Biology (044) · Class XII · Chapter-wise Board Questions

Identify the plant in which emasculation is not required for artificial hybridization.

1. Rice
2. Wheat
3. Pea
4. Papaya

Given below are stages of embryo sac formation from megaspore mother cell. Identify the correct option for the cell division marked a, b, c and d.

1. a – Meiosis-I, b – No division, c – Mitosis, d – Meiosis-II
2. a – Meiosis-I, b – Meiosis-II, c – No division, d – Mitosis
3. a – Mitosis, b – Meiosis-I, c – Meiosis-II, d – No division
4. a – No division, b – Mitosis, c – Meiosis-I, d – Meiosis-II

Assertion (A): Apomixis leads to production of genetically identical offsprings.

Reason (R): Apomixis involves fertilization between two genetically similar plants.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation for Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation for Assertion (A).
3. Assertion (A) is true, Reason (R) is false.
4. Assertion (A) is false, Reason (R) is true.

Select the correct option for the pair of plants pollinated by water.

1. Vallisneria and Hydrilla
2. Zostera and Water lily
3. Water lily and Parthenium
4. Water hyacinth and Water lily

Choose the option that gives the correct number of pollen grains that will be formed after 325 microspore mother cells undergo microsporogenesis.

1. 325
2. 650
3. 1300
4. 975

Assertion (A): Cleistogamous flowers have assured seed set.

Reason (R): Cleistogamous flowers are invariably autogamous and do not depend on any pollinating agents.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Identify the parts P, Q, R, S in the figure given below and select the option in the correct order.

The undifferentiated sheath that encloses the radicle and root cap in a monocot embryo, is known as :

1. Coleoptile
2. Coleorrhiza
3. Epiblast
4. Scutellum

Assertion (A): Apomictic embryos are genetically identical to the parent plant.

Reason (R): Apomixis is the production of seeds without fertilisation.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

The diagram given below shows labelling of four parts of a dicot embryo during its development as P, Q, R and S.

Choose the option that indicates correct labelling of ‘P’, ‘Q’, ‘R’ and ‘S’ of embryo in different stages of its development :

1. P – Egg; Q – Suspensor; R – Radicle; S – Cotyledon
2. P – Zygote; Q – Suspensor; R – Cotyledon; S – Plumule
3. P – Egg; Q – Radicle; R – Suspensor; S – Cotyledon
4. P – Zygote; Q – Suspensor; R – Cotyledon; S – Radicle

How many pollen grains and ovules are likely to be formed in the anther and the ovary of an angiosperm bearing 50 microspore mother cells and 50 megaspore mother cells respectively ?

1. 100, 25
2. 200, 50
3. 50, 50
4. 200, 100

Given below is a diagram of T.S. of a monocot seed with parts I, II & III labelled :

Choose the option where parts I, II and III are identified correctly.

1. I – Pericarp; II – Endosperm; III – Scutellum
2. I – Pericarp; II – Endosperm; III – Coleorhiza
3. I – Scutellum; II – Pericarp; III – Coleorhiza
4. I – Coleorhiza; II – Scutellum; III – Pericarp

Select the statements that are true for a typical dicotyledonous embryo from the given options.

1. It consists of an embryonal axis and scutellum.
2. The portion of embryonal axis above the level of cotyledon is epicotyl.
3. The portion of embryonal axis below the level of cotyledon is coleorhiza.
4. The lower end of the embryo has radicle covered with a root cap.

Choose the correct answer :

1. (i) and (ii)
2. (i) and (iii)
3. (iii) and (iv)
4. (ii) and (iv)

Select the statements that are true for pollination mechanism in flowering plants from the given options.

1. In Vallisneria, the female flowers are pollinated by pollen grains inside the water.
2. In Zostera, pollen grains are released on the surface of water.
3. In most of the water-pollinated species, pollen grains are covered by a mucilaginous coating.
4. Pollination by water is quite rare and limited to about 30 genera.

Choose the correct answer :

1. (i) and (ii)
2. (ii) and (iii)
3. (iii) and (iv)
4. (i) and (iv)

Select the statements that are true for the seed of angiosperm from the given options :

1. Non-albuminous seeds have no residual endosperm.
2. Residual, persistent nucellus in wheat is known as perisperm.
3. Integuments of ovules harden as tough protective seed coat.
4. Metabolic activity of the embryo slows down in dormancy.

Choose the correct option :

1. (i) and (ii)
2. (ii) and (iii)
3. (iii) and (iv)
4. (i) and (iv)

Given below are the events that are observed in an artificial hybridisation programme. Arrange them in the correct sequential order and select the correct option.

1. Re-bagging
2. Selection of parents
3. Bagging
4. Dusting the pollens on stigma
5. Emasculation
6. Collection of pollens from male parent

Options :

1. (ii), (iii), (v), (vi), (iv), (i)
2. (ii), (v), (iii), (vi), (iv), (i)
3. (v), (ii), (iii), (vi), (i), (iv)
4. (ii), (iii), (vi), (iv), (v), (i)

Choose the option that correctly describes the gynoecium of Michelia :

1. Multicarpellary, Apocarpous
2. Bicarpellary, Apocarpous
3. Multicarpellary, Syncarpous
4. Bicarpellary, Syncarpous

Identify the various parts, ‘a’, ‘b’ and ‘c’, in the given diagram of ovule :

1. a – Embryo sac, b – Inner integuments, c – Outer integuments
2. a – Inner integuments, b – Nucellus, c – Chalazal end
3. a – Hilum, b – Funicle, c – Embryo sac
4. a – Mycropylar end, b – Hilum, c – Inner integuments

Assertion (A): All the events starting from pollen landing on stigma till pollen tube entering the ovule are included in pollen-pistil interaction.

Reason (R): Pollen-pistil interaction ensures that only suitable pollens germinate on the stigma.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

In which of the following plants are both male and female flowers born on the same plant and the mode of pollination can be geitonogamy or xenogamy ?

1. Papaya
2. Date Palm
3. Maize
4. Spinach

An angiosperm embryo sac is located within the :

1. Placenta
2. Megasporangium
3. Nucellus
4. Ovary

The part of the ovule that develops into protective coats of a seed after fertilization in a typical flowering plant is :

1. embryo sac
2. nucellus
3. integuments
4. megaspore

In which one of the following floral plants are many embryos formed in the seeds without fertilisation of the egg cell ?

1. Black pepper
2. Mustard
3. Groundnut
4. Citrus

Assertion (A): The zygote gives rise to heart-shaped embryo and subsequently proembryo in most angiosperms.

Reason (R): The zygote is present at the micropylar end of the embryo sac and develops into an embryo.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

In a fertilized ovule of an angiosperm, the cells in which n, 2n and 3n conditions respectively occur are :

1. antipodal, zygote and endosperm
2. zygote, nucellus and endosperm
3. endosperm, nucellus and zygote
4. antipodals, synergids and integuments

Study the following diagram of Transverse Section of a young anther of an angiosperm :

Select the option where parts ‘A’, ‘B’ and ‘C’ are correctly identified.

1. A – Connective, B – Endothecium, C – Pollen grain.
2. A – Endothecium, B – Connective, C – Pollen grain.
3. A – Pollen grain, B – Connective, C – Endothecium.
4. A – Endothecium, B – Pollen grain, C – Connective.

A phenomenon where a male insect mistakenly identified the patterns of a orchid flower as the female insect partner, and tries to copulate and thereby pollinates the flower is said to be :

1. Pseudocopulation
2. Pseudopollination
3. Pseudoparthenocarpy
4. Pseudofertilisation

Identify the correct labellings in the figure of a fertilised embryo sac of an angiosperm given below :

1. A – zygote, B – degenerating synergids, C – degenerating antipodals, D – PEN
2. A – degenerating synergids, B – zygote, C – PEN, D – degenerating antipodals
3. A – degenerating antipodals, B – PEN, C – degenerating synergids, D – zygote
4. A – degenerating synergids, B – zygote, C – degenerating antipodals, D – PEN

Long ribbon-like pollen grains are seen in some :

1. Aquatic plants
2. Wind-pollinated grasses
3. Gymnosperms
4. Bird-pollinated flowers

Choose the option that gives the correct number of pollen grains that will be formed after 325 microspore mother cells undergo microsporogenesis.

1. 325
2. 650
3. 1300
4. 975

Assertion (A): Endosperm is completely consumed during the development of embryo in ex-albuminous seeds.

Reason (R): Castor, pea and beans are all examples of ex-albuminous seeds.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Which of the following seeds have remained alive for the longest period ?

1. Phoenix dactylifera
2. Striga asiatica
3. Mangifera indica
4. Yucca gigantea

Select the option that shows the correctly identified ‘U’, ‘X’, ‘Y’ and ‘Z’ in a developing dicot embryo.

1. X – Plumule (2n), Y – Suspensor (n), Z – Cotyledon (2n), U – Radicle (2n).
2. X – Plumule (2n), Y – Suspensor (n), Z – Radicle (2n), U – Cotyledon (2n).
3. X – Suspensor (2n), Y – Cotyledon (2n), Z – Radicle (2n), U – Plumule (2n).
4. X – Cotyledon (2n), Y – Radicle (n), Z – Plumule (n), U – Suspensor (n).

Select the option that correctly matches with the labelling in the given diagram of T.S. of an apple which categorizes it as a false fruit.

1. P – Thalamus
2. Q – Seed
3. R – Endocarp
4. S – Mesocarp

Assertion (A): Banana is a parthenocarpic fruit.

Reason (R): It develops only from the ovary.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

The male gametes in plants are formed by:

1. Mitotic division of nucleus of vegetative cell
2. Meiotic division of nucleus of vegetative cell
3. Mitotic division of nucleus of generative cell
4. Meiotic division of nucleus of generative cell

A researcher observes that in a particular flowering plant, the pistil matures several days before the stamens in all flowers of the plant. What is the most significant consequence of this timing difference?

1. It guarantees self-pollination
2. It promotes autogamy
3. It ensures cross-pollination
4. It leads to geitonogamy

The primary endosperm nucleus is formed by fusion of which of the following?

1. A male gamete and a female gamete
2. A male gamete and two polar nuclei
3. A female gamete and two synergids
4. Two male gametes and an egg cell

Assertion (A): The ability of the pistil to recognise the pollen is the result of a continuous dialogue between pollen and pistil.

Reason (R): This electrical dialogue allows only compatible pollen to germinate.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

(a) (i) How does a farmer use dormancy of seed to his advantage ?

(ii) Differentiate between pea seed and castor seed.

OR

(b) Identify the stage of follicle where primary oocyte undergoes first meiotic division.

Also mention the products of this division.

(a) Write one way by which apomictic seeds can be developed.

(b) Why do farmers prefer apomictic seeds over hybrid seeds ?

(a) Mention the functions of each of the following :

1. Tassels of Corn Cob
2. Scutellum

OR

(b) Farmers prefer apomictic seeds over hybrid seeds. Give any two reasons.

Attempt either (a) or (b).

(a) How is it possible in Oxalis and Viola plants, to produce assured seed sets even in the absence of pollinators ?

OR

(b) Write the ploidy of the cells of the nucellus, MMC (Megaspore Mother Cell), the functional megaspore and female gametophyte.

Student to attempt either option (A) or (B) :

(A) (i) Write two crucial changes, the seed undergoes while reaching maturity that enable them to be in a viable state until the onset of favourable conditions.

(ii) Name the oldest viable seed excavated from Arctic Tundra as per the records.

OR

(B) (i) Pea flower produce assured seed sets. Give reason.

(ii) In case of Polyembryony, an embryo ‘P’ develops from a synergid and the embryo ‘Q’ develops from the nucellus. State the ploidy of embryo ‘P’ and ‘Q’.

(a) How many meiotic divisions will a wheat plant undergo in order to produce 100 zygotes /100 grains ? Calculate and give explanation.

OR

(b) How many pollen grains and ovules are likely to be formed in the anther and the ovary of an angiosperm bearing 35 microspore mother cells and 35 megaspore mother cells respectively ?

Given below is a transverse sectional view of an apple. Label the following parts (i) and (ii) and write down their functions.

Identify A, B, C and D in the table given below :

1. “Farmers prefer apomictic seeds to hybrid seeds.” Justify giving two reasons.

OR

2. Mention one advantage and one disadvantage of amniocentesis.

1. From which end of the ovule, and how does the pollen tube gain its entry into the embryo sac of a Hibiscus flower ?
2. State the fate of the male nuclei present in the pollen tube.

1. Explain the process of the development of a male gametophyte in an angiosperm.
2. Why is it called a male gametophyte ?

The male and female flowers of corn plant (maize) are well adapted for pollination by wind. Justify.

Attempt either option A or B.

A. During artificial hybridization, it is important to ensure that only desired pollen grains are used for pollination. How is it ensured?

OR

B. Why is manual transfer of desired pollen grains relatively easy in pea plants for hybridization, but in wheat, pollen grains are often utilized from pollen banks for hybridization purposes?

Attempt either option A or B.

A. Geitonogamy can be compared with cross-pollination as well as self-pollination. Comment.

OR

B. Mohit wants to produce hybrid seeds in a plant in his field in which male and female flowers mature at the same time and are close together. Suggest one strategy to promote only desired cross pollination and justify your answer.

(a) Do all pollen grains remain viable for the same length of time ? Support your answer with two suitable examples.

(b) How are pollen grains stored in pollen banks ?

Draw a neat diagram of megasporangium of an angiosperm and label any six parts.

Draw a neat diagram of enlarged view of one microsporangium of a Young anther of an angiosperm. Label the different layers of the wall and write the functions of the outermost and innermost layer.

Answer the following questions :

(a) Explain the different ways by which apomictic seeds can be developed. [2]

(b) Mention one advantage of apomictic seeds for farmers. [1]

Draw a neat diagram of a maize grain showing the internal structure and label any five parts.

Differentiate between wind-pollinated and insect-pollinated flowers. Give an example of each type.

List any three outbreeding devices that flowering plants have developed for cross-pollination and explain how they help to encourage cross-pollination.

(a) Draw a diagram of L.S. of an anatropous ovule of an angiosperm. Label the following parts :

1. Nucellus
2. Outer integument
3. Antipodal cells
4. Polar nuclei

(b) How does endosperm in angiosperms become triploid ?

(a) A bilobed dithecous anther has 200 microspore mother cells per microsporangium. How many male gametophytes can be produced by this anther ?

(b) Write the composition of intine and exine layers of a pollen grains.

Given below is a flower with its characteristic features specialised for the most common type of abiotic pollination.

Answer the following questions based on the above diagram :

1. Name the mode of abiotic pollination that will be adopted by the given plant species in the above picture.
2. State the need of exposed large feathery stigmas for the flower.
3. What will be the two important adaptations in the pollen grains of the flowers pollinated by the above mode of pollination ?
4. What could be the probable reason for the petals being small and non-green ?

Many of the flowering plants producing hermaphrodite flowers have developed many devices to discourage self-pollination and to encourage cross-pollination. Given below is a picture of one such outbreeding device in a flowering plant. Study the picture and answer the questions that follow :

1. Explain how the given type of pollination is advantageous to the plant.
2. Can this flowering plant show geitonogamy ? Justify your answer.

Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow.

Note :

All plants belong to the same species.

× – No pollen tube growth/inhibition of pollen germination on stigma.

✓ – Pollen germination on stigma.

1. Name and define the outbreeding device described in the above table.
2. Explain what would have been the disadvantage to the plant in the absence of the given strategy.

Draw a longitudinal section of pistil of a flower showing growth of the pollen tube. Label the part :

1. through which the pollen tube moves down.
2. the cell wherein the pollen tube releases its contents.

Draw a well labelled diagram of sectional view of male gametophyte/microspore of an angiosperm and write the functions of any two parts labelled. (Any four labels).

If the cells in the leaves of a maize plant contain 10 chromosomes each, write the number of chromosomes in its endosperm and zygote. Name and explain the process by which an endosperm and a zygote are formed in maize.

One of the major approaches of crop improvement programme is Artificial Hybridisation. Explain the steps involved in making sure that only the desired pollen grain pollinate the stigma of a bisexual flower by a plant breeder.

(a) Draw a neat diagram of a mature angiospermic embryo sac and label any four cellular components.

(b) Write the function of filiform apparatus.

In the post-fertilization embryo sac shown in figure, structure 'P' results from the fusion of one male gamete with the egg cell, and structure 'Q' results from the fusion of the other male gamete with the polar nuclei.

1. Identify structure 'P' and structure 'Q' and state their ploidy.
2. Evaluate the following statement: “The division of 'P' always precedes the division of 'Q'.” Justify your evaluation based on the nutritional requirements for seed development.
3. Which characteristic feature of endosperm helps in its nutritive role?

The following question is based on pollination. Study the figures carefully and answer the questions that follow.

1. Give the scientific terms for the processes taking place in Figures A and B respectively.
2. Mention two conditions necessary for the process occurring in Figure B.
3. (i) State one advantage and one disadvantage of the process occurring in Figure B.

OR

3. (ii) Name one plant where, in some flowers only, the process in Figure B takes place and give the reason responsible for it.

Given below is a set of information about some fruits and seeds.

On the basis of the information provided above, answer the following questions with justification for each answer.

A. How many embryo sacs will be present in each ovule of S before maturation and how many egg(s) will be present in each embryo sac when the embryo sac is developed from a single megaspore? (1)

B.

1. Which of these fruits exhibits polyembryony? Will their embryos exhibit genetic variation? Justify.
2. What will be ploidy of the embryonic cells in the above case? (2)

Attempt either subpart C or D.

C. Which of these fruits can be considered as parthenocarpic? Give a reason. (1)

OR

D. Which of the fruits P, Q, R or S is a true fruit with seeds? Give reason. (1)

(a) (i) Explain the role of stigma in pollen pistil interaction. [1]

(ii) Describe the post pollination events leading to double fertilization in angiosperms starting with 2-celled pollen grain. [4]

OR

(b) (i) Explain menstrual phase in the menstrual cycle of human female. [1]

(ii) Why is follicular phase also called proliferative phase ? [1]

(iii) Explain the events that occur in Graafian follicle at the time of ovulation and thereafter. [2]

(iv) Draw a Graafian follicle and label – Antrum and secondary oocyte. [1]

Student to attempt either option-(A) or (B) :

(A) (a) Distinguish between the two cells enclosed in a mature male gametophyte of an angiosperm.

(b) Study the diagram given below showing the modes of pollination. Answer the questions that follow.

1. The given diagram shows three methods of pollen transfer in plants. Examine them carefully and write the technical terms used for pollen transfer methods ‘1’, ‘2’ and ‘3’.
2. How do the following plants achieve pollination successfully ?
   1. Water lily
   2. Vallisneria
3. Write advantages of pollen transfer in method ‘3’.

OR

(B) Given below is the diagram of human ovum surrounded by a few sperms. Observe the diagram and answer the questions that follows :

1. Compare the fate of sperms ‘P’, ‘Q’ and ‘R’ shown in the diagram.
2. Write the role of Zona pellucida in this process.
3. Analyse the changes occurring in the ovum after the entry of sperm.
4. How acrosome and middle piece of a human sperm are able to play an important role in human fertilization ?

Student to attempt either option (A) or (B).

(A) (i) Describe the process of megasporogenesis in an angiosperm.

(ii) Draw a diagram of a mature embryo sac of an angiosperm. Label its any four parts.

OR

(B) The reproductive cycle in the female primates is called menstrual cycle. The first menstruation begins at puberty.

Answer the following questions :

1. Name the four phases of menstrual cycle in a proper sequence.
2. How long does the menstrual phase last in a menstrual cycle ?
3. When and why hormones estrogen and progesterone reach their peak levels respectively, in the menstrual cycle ?
4. Give the significance of LH surge.

1. 1. Explain how does double fertilisation take place in a flowering plant.
   2. Write the fate of the products of double fertilization in these plants.

OR

2. 1. Explain the structure of testicular lobules in human male reproductive system. Name the two types of cells present in the seminiferous tubules and state their role.
   2. Describe the role of hypothalamic hormone GnRH in spermatogenesis.

1. 1. Explain the structure of a typical monocotyledonous embryo of a flowering plant.
   2. How are multiple embryos formed in a citrus fruit ? What is the mechanism known as ?

OR

2. 1. Name and explain the structural organisation of the male sex accessory ducts in the human male reproductive system.
   2. Describe the role of gonadotropin FSH in the regulation of spermatogenesis.

1. 1. Explain the structure of a mature embryo sac of a typical flowering plant.
   2. How is triple fusion achieved in these plants ?

OR

2. Describe the changes in the ovary and the uterus as induced by the changes in the level of pituitary and ovarian hormones during menstrual cycle in a human female.

(a) (i) Draw a diagram of an enlarged view of transverse section (T.S.) of one microsporangium of an angiosperm and label the following parts :

1. Tapetum
2. Middle layers
3. Endothecium
4. Microspore mother cell

(ii) Write the function of Tapetum.

(iii) Explain the following giving reasons :

1. Pollen grains are well-preserved as fossils.
2. Pollen tablets are in use by people these days.

OR

(b) (i) Where does spermatogenesis occur in human testes ? Describe the process of spermatogenesis up to the formation of spermatozoa.

(ii) Trace the path of movement of spermatozoa from the testes upto the ejaculatory duct.

(a) (i) Explain the development of male gametophyte in an angiosperm.

(ii) Draw a labelled diagram of a three-celled male gametophyte.

OR

(b) (i) Draw a diagrammatic sectional view of ovary of human female and label the following :

1. Blood vessels
2. Primary follicle
3. Tertiary follicle
4. Ovum

(ii) At which stage of life are primary follicles formed in a human female ?

(iii) Explain the events (both hormonal and structural) that occur at the time of ovulation till the onset of the next menstrual cycle.

(a) (i) Explain the process of double fertilization in an angiosperm starting from the germination of pollen grains on the stigma, mentioning the ploidy of the end products formed at the end. State the role of synergids during the course of the process.

(ii) Why does the development of endosperm precede that of the embryo ?

OR

(b) (i) Mention the site where fertilisation of the ovum occurs in a human female. Explain the process of fertilization and mention how polyspermy is prevented.

(ii) Name the embryonic stage that gets implanted in the uterus. Explain the process of implantation in a human female.

1. 1. Explain any four devices that flowering plants have developed to encourage cross-pollination.
   2. Why do plants discourage self-pollination ? State any one reason.

OR

2. Explain the ovarian and uterine events taking place along with the role of pituitary and ovarian hormones, during menstrual cycle in a normal human female under the following phases :
   1. Follicular phase/proliferative phase
   2. Luteal phase/secretory phase
   3. Menstrual phase

(a) (i) Draw a labelled diagram of a fertilised embryo sac of an angiosperm. (label any four parts)

(ii) Explain double fertilisation in angiospermic plant.

OR

(b) (i) Draw a labelled diagram of a cross-section of human seminiferous tubule. (label any four parts)

(ii) Explain the hormonal regulation of spermatogenesis.

1. Study the diagram given below showing the modes of pollination. Answer the questions that follow.

   

   1. The given diagram shows three methods of pollen transfer in plants. What are the technical terms used for pollen transfer methods ‘1’, ‘2’ and ‘3’ ?
   2. How do the following plants achieve pollination successfully ?
      1. Water lily
      2. Vallisneria
   3. Flowering plants have developed many devices to avoid inbreeding depression. Explain one hereditary and one physiological device which helps plants to achieve this target.

OR

2. Observe the diagram given below showing the menstrual cycle of a normal human female and answer the questions that follow :

   

   Numbers indicate the days of the menstrual cycle

   1. What are the suitable technical terms used for the following ?
      1. Days 1 – 7
      2. Days 8 – 12
      3. Days 16 – 28
      4. Days 13 – 15
   2. Explain the role of ovarian and pituitary hormones during the following time periods :
      1. Days 8 – 12
      2. Days 13 – 15
      3. Days 16 – 28

1. 1. Explain the monosporic development of embryo sac in the ovule of an angiosperm.
   2. Draw a diagram of the mature embryo sac of an angiospermic ovule and label any four parts in it.

OR

2. 1. Explain the formation of placenta after the implantation in a human female.
   2. Draw a diagram showing human foetus within the uterus and label any four parts in it.

Select the option that shows correct statements :

1. Corpus luteum secretes progesterone.
2. Only FSH attains a peak level in middle of cycle.
3. LH surge induces rupture of graafian follicle.
4. Luteal phase of menstrual cycle is also called proliferative phase.

Options :

1. Only (ii) is correct.
2. (i) and (iii) are correct.
3. Only (iv) is correct.
4. (ii) and (iv) are correct.

Which connective tissue connects ovary to pelvic wall and uterus ?

1. Tendons
2. Ligaments
3. Cartilage
4. Bone

Foetal ejection reflex in human female triggers the release of which hormone ?

1. Oxytocin from foetal pituitary gland
2. hCG from placenta
3. Progesterone from corpus luteum
4. Oxytocin from maternal pituitary gland

Select the phase of menstrual cycle in which the remaining parts of Graafian follicle transform into the corpus luteum.

1. Secretory phase
2. Proliferative phase
3. Menstrual phase
4. Ovulatory phase

The foetal ejection reflex in human triggers the release of _________ hormone from __________.

Fill in the blanks by choosing right option.

1. oxytocin, foetal pituitary
2. oxytocin, maternal pituitary
3. human chorionic gonadotropin, placenta
4. progesterone, corpus luteum

In a human female, menstrual cycle of 28 days is represented by the diagram given below.

Select the correct statement related with this diagram.

1. Primary follicle of ovary matures into Graafian follicle in phase II.
2. The hormone secreted in large amounts in phase III is also responsible for maintaining pregnancy in human females.
3. Corpus luteum secretes progesterone in phase I, however it degenerates completely in phase III.
4. Both (A) and (B).

Assertion (A): The embryo with 8 to 16 blastomeres is called a morula.

Reason (R): The morula continues to divide and transform into trophoblast.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

The path of the sperm transport is shown below. Identify P and Q and select the correct option.

1. P – Vasa efferentia, Q – Ureter
2. P – Ejaculatory duct, Q – Vas deferens
3. P – Vasa efferentia, Q – Vas deferens
4. P – Vas deferens, Q – Vasa efferentia

Match the following items of Column-I with that of Column-II :

Choose the option that matches Column-I with Column-II correctly.

1. (a)–(iv), (b)–(i), (c)–(ii), (d)–(iii)
2. (a)–(i), (b)–(ii), (c)–(iii), (d)–(iv)
3. (a)–(ii), (b)–(i), (c)–(iv), (d)–(iii)
4. (a)–(ii), (b)–(iv), (c)–(iii), (d)–(i)

The number of autosomes present in a human secondary spermatocyte

1. 44
2. 22
3. 23
4. 46

Assertion (A): Corpus luteum secretes the hormone, progesterone.

Reason (R): Hormone Progesterone is essential for maintenance of the endometrium.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.

Given below are a few statements with reference to the accessory ducts of the human male reproductive system :

1. The seminiferous tubules of the testes open into rete testis then into the vas deferens.
2. The vasa efferentia leave the testes and open into the epididymis.
3. The epididymis leads to vas deferens that ascends into the abdomen.
4. The vas deferens receives a duct from the prostrate gland and opens into the urethra as ejaculatory duct.
5. The urethra originates from the urinary bladder and extends through the penis to its external opening, urethral meatus.

Choose the option with all true statements from the given options :

1. (i), (ii), (iv)
2. (ii), (iii), (v)
3. (ii), (iv), (v)
4. (i), (iii), (iv)

Given below are few statements with reference to the uterus in the female reproductive system :

1. The myometrium exhibits strong contractions during the delivery of the baby.
2. The uterus opens into the cervix through a narrow opening called vagina.
3. The cavity of the cervix and the vagina forms the birth canal.
4. The outermost layer of uterus is a thin membranous perimetrium.
5. The uterus is supported by tendons attached to the pelvic wall.

Choose the option with all true statements from the given options :

1. (i), (ii) and (iv)
2. (ii), (iii) and (v)
3. (ii), (iv) and (v)
4. (i), (iii) and (iv)

Given below are a few statements with respect to spermatogenesis in a human male.

1. Sperms are released from the seminiferous tubules by the process of spermiation.
2. Spermiogenesis involves the maturation of spermatids into sperms.
3. Spermatogonia produce spermatids by the process of spermiogenesis.
4. Meiosis II in secondary spermatocytes results in the formation of four equal haploid spermatids.
5. Primary spermatocyte completes the first meiotic division forming two equal, diploid cells called secondary spermatocytes.

Choose the option with all true statements from the given options :

1. (i), (ii) and (iv)
2. (ii), (iii) and (v)
3. (ii), (iv) and (v)
4. (i), (iii) and (iv)

Which of the following statements are true in respect of chorionic villi in humans ?

1. It appears after implantation of human embryo in the uterus.
2. It becomes interdigitated with cervical tissue of female reproductive tract.
3. It increases the surface area for exchange of materials.
4. It develops from the inner cell mass of blastocyst.

1. (i) and (ii)
2. (ii) and (iii)
3. (i) and (iv)
4. (i) and (iii)

Which one of the following hormones is secreted by the human placenta that helps in the maintenance of pregnancy ?

1. Relaxin
2. Human Chorionic Gonadotropin
3. Oxytocin
4. Human Placental Lactogen

In humans, the secondary oocyte completes meiotic division when :

1. it gets implanted in the uterine endometrium.
2. it is released from the matured Graafian follicle.
3. it is penetrated by the sperm cell.
4. acrosomal enzymes break down the zona pellucida.

Select the option that gives the correct identification of ovum, morula and blastocyst in a human female reproduction system as shown in the following diagram :

1. Ovum – B, Morula – D, Blastocyst – F
2. Ovum – A, Morula – B, Blastocyst – G
3. Ovum – A, Morula – E, Blastocyst – G
4. Ovum – B, Morula – D, Blastocyst – G

Estrogen is secreted by :

1. Corpus luteum
2. Membrane granulosa of Graafian follicle
3. Pituitary gland
4. Germinal epithelium

In which one of the following options does the endocrine gland correctly match with its hormonal secretion and its function ?

1. Sertoli cells – Testosterone – Development of secondary sexual characteristics
2. Placenta – Estrogen – Initiates secretion of milk
3. Leydig cells – Androgen – Initiates the production of sperms
4. Ovary – FSH – Stimulates follicular development

Which of the following options correctly matches the name of the hormone to its site of production in the human body ?

1. P-i, Q-iii, R-ii, S-iv
2. P-i, Q-iv, R-iii, S-ii
3. P-iii, Q-iv, R-i, S-ii
4. P-ii, Q-iii, R-i, S-iv

During the menstrual cycle of a human female, formation of graafian follicle is stimulated by secretion of which of the following gonadotropin hormones?

1. Estrogen and progesterone
2. FSH and Estrogen
3. FSH and LH
4. Progesterone and LH

During the early stage of human embryonic development, the blastomeres are arranged into an outer layer and an inner group of cells known as the Inner Cell Mass (ICM). What is the fundamental significance of the outer layer, the trophoblast?

1. It is responsible for forming the primary germ layers (ectoderm, mesoderm, endoderm).
2. It provides essential nutrients to developing embryo and helps in its implantation.
3. It secretes colostrum which contains antibodies.
4. It gives rise to all the organs of the future embryo (organogenesis).

Assertion (A): Spermatogenesis is an ongoing process throughout the reproductive life of a human male, while oogenesis is a discontinuous process.

Reason (R): Oogenesis begins during the embryonic stage, gets arrested at prophase-I, resumes after puberty, and is arrested again at metaphase-II.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

(a) (i) Name the organ that forms a connection between foetus and the uterus of a pregnant human female. [½]

(ii) How does it support both nutrition and hormonal regulation ? [1½]

OR

(b) Give reasons for :

1. All copulations do not lead to pregnancy.
2. Meiosis I in spermatogenesis and oogenesis are markedly different.

1. 1. Explain why the milk produced by the mother during the initial days of lactation is considered to be very essential for the newborn infant.
   2. What is the term used for the milk produced during the initial days of lactation ?

OR

2. Many children in the metro cities are suffering from a very common exaggerated response of the immune system to certain weak antigens in air.
   1. What is the term used for the above mentioned disease ?
   2. Name the main type of antibody produced by the immune system in response to this disease.
   3. Which two main inflammation-causing chemicals are produced by the mast cells in such an immune response ?

1. “A fully developed foetus initiates its delivery from the mother’s womb.” Explain.

OR

2. Give reasons for the following :
   1. Why can a woman generally not conceive a child after 50 years of age ?
   2. Polar bodies are formed during oogenesis and not during spermatogenesis.

Study the graph given below that represents the changes in the thickening of the uterine wall in women ‘X’ and women ‘Y’ over a period of one month :

What does the graph with respect to woman ‘X’ and woman ‘Y’ indicate ? Give suitable reason.

State the cellular nature and functions of myometrium and endometrium.

The diagram given below shows a developmental stage of human embryo. Answer the following questions with reference to it :

1. Identify and name the human embryonic stage shown.
2. Mention its exact location in the normal pregnancy of a woman.
3. Write one function of each of the two parts labelled ‘X’ and ‘Y’.

The graph given below shows the number of primordial follicles per ovary in women at different ages. Study the graph and answer the questions that follow.

1. What is the average age of the women at the onset of menopause ?
2. At what age are maximum primordial follicles present in the ovary, according to the given graph ?

Differentiate between Follicular phase and Luteal phase of the Menstrual cycle in human females on the basis of the following criteria :

1. Days of their occurrence in the cycle
2. Stage of the follicle
3. Hormones influencing the phases
4. State of endometrium

Explain the process of formation of placenta in a human female after the implantation of the blastocyst in the endometrium of the uterus.

Explain the neuroendocrine mechanism involved in the process of parturition in a human female leading to the expulsion of the baby out of the uterus through the birth canal.

1. Name and explain the role of inner and middle walls of the human female uterus.
2. Write the location and function of fimbriae in human female.

Given below is the diagram showing a part of the reproductive system of a human female.

(a) Identify ‘Y’ and write its function.

(b) Identify ‘Z’ and write the events that may occur here.

(c) Mention the stage at which the process of oogenesis temporarily gets arrested and name the cells thus formed in the ‘X’ of a baby girl at the time of her birth.

1. Write the characteristics of ‘stem cells’.
2. From where can one obtain ‘stem cells’ in humans ?
3. State any two applications of ‘stem cells’ in curing human diseases.

Given below is a diagrammatic sectional view of a seminiferous tubule. State the developmental process of :

1. 1. ‘b’ from ‘a’.
   2. ‘e’ from ‘d’.
   3. ‘d’ from ‘b’.
2. Identify ‘a’, ‘b’ and ‘c’.

Given below is a figure showing transport of ovum, fertilisation and passage of growing embryo through fallopian tube in a human female. Answer the questions that follow:

1. What will be the ploidy of cells shown in (a) and (c) stage in the figure given below?
2. What will happen if component L as shown in the figure (g) given below does not attach properly to the endometrium?
3. In a pregnant mother (case X), during early pregnancy, the fertilised egg splits into two embryos at stage C shown in the figure given below, resulting in the formation of twins. Will the genome of cells of these two embryos exhibit variation? Justify your answer.

Study the graphs given below for Case 1 and Case 2 showing different levels of certain hormones and answer the question that follows :

(a) Which hormone is responsible for the peak observed in Case 1 and Case 2 ? Write one function of that hormone.

(b) Write changes that take place in the ovary and uterus during follicular phase.

Student to attempt either sub-part (c) or (d) :

(c) Name the hormone Q of Case 2. Write one function of hormone Q.

OR

(d) Which structure in the ovary will remain functional in Case 2 ? How is it formed ?

Read the following passage and answer the questions that follow.

Spermatogenesis is an important primary sex characteristic in humans and all other vertebrates. The process is coordinated and controlled under the influence of hormones. It starts with the onset of puberty in humans and thereafter continues. The primordial cells within the embryonic testis which differentiate into spermatogonia are the precursors of the sperms. These are located at the outer walls of the seminiferous tubules where the process of spermatogenesis proceeds.

(a) State the site of action of FSH in the testes and describe its action thereafter.

OR

(a) Describe the role of LH in the process of spermatogenesis.

(b) Name the cells and their products which undergo :

1. Mitosis and Differentiation
2. Meiosis I and Meiosis II

during the process of spermatogenesis.

(c) Name the accessory ducts that the sperms travel through from seminiferous tubules to reach the epididymis.

In a human female, the reproductive phase starts on the onset of puberty and ceases around middle age of the female. Study the graph given below regarding menstrual cycle and answer the questions that follow :

1. Name the hormones and their source organ, which are responsible for menstrual cycle at puberty.
2. For successful pregnancy, at what phase of the menstrual cycle an early embryo (upto 3 blastomeres) should be Implanted in the Uterus (IUT) of a human female who has opted for Assisted Reproductive Technology (ART) ? Support your answer with a reason.
3. Name the hormone and its source organ responsible for the events occurring during proliferative phase of menstrual cycle. Explain the event.

OR

3. In a normal human female, why does menstruation only occurs if the released ovum is not fertilised ? Explain.

Madhuri, a 17-year-old girl, has been experiencing irregular periods for the past one year. Sometimes, her cycles are as short as 20 days and sometimes as long as 45 days. She occasionally has very heavy bleeding that lasts over a week, causing fatigue and weakness. A doctor reviews her menstrual diary and explains that these changes can be linked to hormonal fluctuations in the hypothalamic-pituitary-ovarian (HPO) axis. He shows Madhuri the lack of a clear ovulation peak and low progesterone levels in her recent cycles.

A. Madhuri experiences heavy bleeding lasting over a week causing fatigue. What possible complication could arise from this condition? (1)

B. Examine how the absence of a distinct LH (luteinizing hormone) surge in the menstrual cycle might explain both the irregularity and heaviness of Madhuri's periods. (2)

Attempt either subpart C or D.

C. Madhuri's cycles vary between 20 and 45 days. What might this irregularity indicate about her ovarian function? (1)

OR

D. If a doctor suspects hypothalamic-pituitary dysfunction in Madhuri, which hormone secretion pattern would you expect to be disrupted? (1)

(a) Trace the events from fertilization till implantation of blastocyst in human female. Also mention the site where fertilization takes place.

OR

(b) (i) Case studies of some couples are given below. They were not able to have kids even though the parents were not taking any precautions. They also do not wish to adopt a child or take the help of donors. Study these cases and suggest an appropriate Assisted Reproductive Technology that could help them.

Case I – Female – Normal Reports
Male – Normal sperms but no connection between epididymis and vas deferens.

Case II – Female – Normal eggs but Fallopian tube blocked.
Male – Normal sperms. Male reports are normal.

Case III – Female – Normal Reports.
Male – Low sperm count with less motility.

(ii) Copper releasing intrauterine devices are very effective and popular contraceptive devices. Name any two copper releasing IUDs. Write two reasons that make them effective contraceptives.

(a) Oogenesis is a discontinuous process that begins before birth and is completed after puberty.

(i) Trace the development of a gamete mother cell till its release from the ovary during ovulation. [4]

(ii) Name the two pituitary hormones that play an important role in the process. [1]

OR

(b) (i) Draw a labelled two-celled structure of male gametophyte of an angiosperm. [1]

(ii) Name the three layers that surround the cytoplasm of a male gametophyte starting from innermost to outermost layer. [1½]

(iii) Which organic material makes the outermost layer ? Mention its advantage. [1½]

(iv) Why is the outermost layer of male gametophyte not continuous ? [1]

(a) Study the flow chart given below. Name the hormones involved at each stage and explain their functions.

Hypothalamus
↓
Pituitary
↓
Ovary
↓
Pregnancy

OR

(b) (i) Draw a diagram of L.S. of maize grain and label its any six parts.

(ii) Differentiate between perisperm and endosperm giving one example of each.

(a) Briefly explain the events of fertilisation and implantation in an adult human female.

OR

(b) (i) Arrange the following hormones in sequence of their secretion in a pregnant woman : hCG; LH; FSH; Relaxin. [1]

(ii) Mention the source and the functions of the above mentioned hormones. [4]

Attempt either (a) or (b).

(a) Draw a flow chart to show hormonal control of the human male reproductive system.

OR

(b) Explain the changes that the primary oocyte undergoes while in different follicular stages before ovulation.

1. Study the given diagram showing the sectional view of a seminiferous tubule.

   

   Answer the following questions :

   1. Label A, B, C and D in the figure.
   2. What will be the number of chromosomes in secondary spermatocyte and spermatid respectively ?
   3. Explain the terms – Spermiogenesis and Spermiation.

OR

2. Study the figures given below showing initial stages in the formation of female gametophyte and answer the questions that follow.

   

   1. Identify (P) and (Q).
   2. 1. What kind of division does cell (P) undergo to form (Q) ?
      2. How many (Q) cells form the embryo sac ? What is the name given to such kind of development ?
      3. How many free nuclear mitotic divisions will the functional megaspore undergo to form the embryo sac ?
      4. Describe the structure of a mature female gametophyte.

1. The given diagram shows the sectional view of a seminiferous tubule of Human testis :

1. Name and describe the process depicted in the diagram which results in the development of spermatozoa.
2. Identify the cell where you are seeing a cluster of spermatozoa attached in the diagram. Write the function of the cell.

OR

2. 

   Observe the picture of Commelina plant bearing two types of flowers given above.

   1. Identify the two types of flowers labelled ‘A’ and ‘B’ in the picture.
   2. Compare the two types of flowers with reference to :
      1. Characteristic feature
      2. modes of pollination
   3. List any two ‘out breeding devices’ in flowering plants. Explain why do plants develop such devices.

1. 1. Draw a diagram of a human sperm. Label any four parts and write their functions.
   2. In a human female, probability of an ovum to get fertilized by more than one sperm is impossible. Give reason.

OR

2. 1. With the help of labelled diagram only, show the different stages of embryo development in a dicot plant.
   2. Endosperm development precedes embryo development. Justify.

1. Given below is a diagrammatic representation of a human ovum.

   

   1. Identify the parts ‘a’, ‘b’ and ‘c’.
   2. This ovum is released from the ovary with incomplete meiotic division. When, where and how is the meiotic division completed ?
   3. How does an ovum ensure the entry of a single sperm during fertilisation ?

OR

2. 1. Double fertilisation is an event unique to all flowering plants. Explain the process.
   2. Give a reason for the following :
      1. A seed of an orange has many embryos.
      2. Cashew is a false fruit but Guava is a true fruit.

(a) (i) Draw a labelled diagram of a matured human ovum ready for fertilization. Explain the events thereafter, leading to zygote formation.

(ii) It is said that the sex of the baby is decided as soon as the process of fertilization begins. Justify the statement.

OR

(b) (i) Write any four steps that you would recommend to improve the human reproductive health standards in India.

(ii) Refer to the following diagrams ‘A’ and ‘B’ showing sterilization in humans and answer the questions.

1. Identify the labellings in the diagrams ‘A’ and ‘B’ where the procedure is carried out.
2. Write the technical terms, and the procedures followed in the above-mentioned techniques.

How many of the following features are related to Nirodh – a popular brand of condoms ?

1. Prevention of sexually transmitted infections.
2. Phagocytosis of sperms.
3. Male contraceptive device.
4. Acts as chemical barrier.
5. Physiological changes in cervical mucus.

1. (i), (ii), (iv)
2. (i) and (iii)
3. (i), (ii), (v)
4. (ii) and (iv)

A female undergoing IVF treatment has blocked fallopian tube. The technique by which the embryo with more than 8 blastomeres will be transferred into the female for further development is :

1. ZIFT
2. GIFT
3. IUT
4. AI

Assertion (A): Determining the sex of an unborn child followed by MTP is an illegal practice.

Reason (R): Amniocentesis is a practice to test the presence of genetic disorders.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Assertion (A): Saheli is the World’s first non-steroidal oral contraceptive pill.

Reason (R): It has been developed by National Institute of Immunology, New Delhi.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.

Assertion (A): ‘Saheli’, an oral contraceptive inhibits ovulation and increases phagocytosis of sperms.

Reason (R): It is a non-steroidal preparation.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Assertion (A): Cu-T, Cu-7 and LNG-20 are the most widely used copper-releasing IUDs.

Reason (R): Cu-ions in IUDs effectively suppress sperm motility and the fertilising capacity of sperms.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Assertion (A): Male contraceptive ‘Nirodh’ works on the principle of avoiding chances of ovum and sperm meeting.

Reason (R): It is made of thin rubber/latex sheath and is used to cover the penis before coitus.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Given below is Column A with a list of certain Assisted Reproductive Technologies (ART), and Column B, with the procedures followed during ART :

Select the correct match :

1. a-i, b-ii, c-iii, d-iv
2. a-iv, b-i, c-ii, d-iii
3. a-iv, b-iii, c-i, d-ii
4. a-i, b-iii, c-iv, d-ii

The periodic abstinence by a couple for family planning should be from :

1. Day 5 to 10 of menstrual cycle
2. Day 13 to 15 of menstrual cycle
3. Day 10 to 17 of menstrual cycle
4. Day 16 to 20 of menstrual cycle

Assertion (A): The laws of our country permit legal adoption and it is as yet, one of the best methods for childless couples looking for parenthood.

Reason (R): Emotional, religious and social factors are no deterrents to the legal adoption of orphaned and destitute children in India.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Study the table given below :

Select the option where contraceptive/contraceptive method are correctly matched with their mode of action.

1. A – III, B – II, C – I, D – IV
2. A – II, B – III, C – I, D – IV
3. A – III, B – I, C – IV, D – II
4. A – IV, B – III, C – II, D – I

Observe the schematic representation of assisted reproductive technology given below :

Identify the most appropriate technique depicted in the above diagram.

1. IUT
2. IUI
3. ICSI
4. ZIFT

Amniocentesis is a technique that is used to :

1. determine any disease of the heart
2. determine any genetic disorder of the foetus
3. determine any disorder of the brain
4. detect any abnormality in the bone formation

Assertion (A): Periodic abstinence is a method in which couples avoid coitus from day 10 to 17 of menstrual cycle.

Reason (R): Periodic abstinence has limited effectiveness because menstrual cycles are not always regular.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Given below are two columns. In Column I the names of four contraceptive devices are given and in Column II the modes of action of the contraceptives are given. Select the option where the contraceptive devices are correctly matched with their respective modes of action.

1. P-ii, Q-iv, R-iii, S-i
2. P-i, Q-ii, R-iii, S-iv
3. P-iii, Q-i, R-iv, S-ii
4. P-iv, Q-iii, R-ii, S-i

A human male decides to adopt a surgical method for contraception. Identify the point in the diagram where a cut would be made and tied.

1. Point S
2. Point R
3. Point Q
4. Point P

Given below are Column A with a list of certain Assisted Reproductive Technologies (ART) and in Column B the procedures followed during ART :

Choose the option where ART correctly matches with the procedure.

1. (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
2. (A)-(iv), (B)-(i), (C)-(ii), (D)-(iii)
3. (A)-(iv), (B)-(iii), (C)-(i), (D)-(ii)
4. (A)-(i), (B)-(iii), (C)-(iv), (D)-(ii)

Assertion (A): Determining the sex of an unborn child followed by MTP is an illegal practice.

Reason (R): Amniocentesis is a practice to test the presence of genetic disorders also.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.

Which one of the following techniques is employed in test tube baby programme ?

1. Intra Cytoplasmic Sperm Injection
2. Intra Uterine Insemination
3. Gamete Intra Fallopian Transfer
4. Zygote Intra Fallopian Transfer

Assertion (A): Cervical caps and vaults are barrier methods of contraception used by human females.

Reason (R): They prevent conception by phagocytosis of sperms.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

A male patient undergoes a medical procedure where a small section of the vas deferens is cut and tied at both ends. Which of the following effects is the intended and direct result of this procedure?

1. Blockage of sperm transport into the ejaculatory duct and urethra.
2. Inhibition of testosterone production by the testes.
3. Suppression of the formation of seminal plasma by accessory glands.
4. Prevention of spermatogenesis in the seminiferous tubules.

How do ‘implants’ act as an effective method of contraception in human females ? Mention one advantage of implants over contraceptive pills.

Define the term ‘amniocentesis’. Why has the government imposed a statutory ban in spite of its importance in the medical field ?

How can childless couples get help by the following assisted reproductive technologies ?

(a) GIFT

(b) ICSI

1. Explain what is meant by the term MTP. What was the main reason to legalize MTP by the Government of India ?

OR

2. Name any two STIs which might occur in a human female. State its two early symptoms.

1. Explain what is meant by the term amniocentesis. How is this technique misused in India ?

OR

2. Name any two VDs which might occur in a human female. State any two complications in a female if it is left untreated.

1. Why are restrictions imposed on MTP in India ? Up to how many weeks or trimesters, is MTP considered relatively safe for a female, if necessary to perform, by a medical practitioner ?

OR

2. Expand PID. Name any two common viral infections transmitted through sexual contact in human females.

Write the basic steps followed in the Assisted Reproductive Technologies (ART) programme to help childless couples. Why is it also known as test tube baby programme ?

(a) Name any two copper releasing intra-uterine devices. State two reasons that make them effective contraceptives.

OR

(b) Name any two outbreeding devices that flowering plants have developed and explain how they help in encouraging cross-pollination.

Oral contraceptives are widely accepted for controlling the increasing rate of population. Name the two important components of oral contraceptives. Why is ‘Saheli’ considered a preferred contraceptive by women ?

1. Intensely lactating mothers generally do not conceive. Why ?
2. Our government has intentionally imposed strict conditions for MTP. Why ?

How do ‘implants’ act as an effective method of contraception in human females ? Mention their one advantage over contraceptive pills.

Study the diagram given below :

(a) Name and explain the procedure shown in the diagram. Mention one of its advantage and one disadvantage. [2]

(b) How is ‘Saheli’ different from other oral pills in terms of its composition and advantage ? [1]

In vitro fertilization (IVF) is a popular method these days that is helping childless couples to bear a child.

(a) Write the different steps that are carried out in this technique. [2]

(b) Would you consider gamete intra fallopian transfer as a type of IVF ? Justify your answer. [1]

Shyam and Radha are expecting their first child with Radha being in her second month of pregnancy with no complications. Shyam’s family has a history of cystic fibrosis while Radha’s family has a history of Down’s syndrome, leading to a concern that the baby may have one of these conditions.

(a) Suggest and explain a way of testing if their baby is at risk for any genetic disorders.

(b) In case of presence of one or both of the abnormalities and posing a risk to the mother’s health, mention one possible option for them to consider. Is that option safe for Radha at the current gestational age ? Justify.

(c) Under what conditions is the process mentioned in (b) illegal ?

(a) List two reasons that make copper releasing IUDs as effective contraceptives.

(b) Explain how the intake of oral contraceptive pills prevent pregnancy in humans.

A village health worker was taking a session with women. She tells them that one has to be careful while using oral pills as a method of birth control. Wrong usage can actually promote conception.

1. Analyse the above statement and compare the merits and demerits of using oral pills and surgical methods of birth control.
2. Village women are confused as to how a thin metallic copper loop can provide protection against pregnancy. Explain the mode of action of IUDs. Give two points.

A woman has certain queries as listed below, before starting with contraceptive pills. Answer them.

(a) What do contraceptive pills contain ? Why are they considered as contraceptives ?

(b) What schedule should be followed for taking these pills ?

Explain the mode of action of contraceptive pills taken by human females. Mention the schedule to be followed for effective outcome.

(a) Why is “in vitro fertilization (IVF)” so named ? State its importance.

(b) Distinguish between GIFT and ZIFT.

Explain the IUI and IUT methods of assisted reproductive technologies.

1. 1. Expand the abbreviations given below, used for different modes of assisted reproductive technologies :
      1. ZIFT
      2. ICSI
      3. IUT
      4. GIFT
   2. Which one of them cannot be considered as a procedure of IVF ? Give reasons in support of your answer.

OR

2. Differentiate between the following :
   1. Perisperm and Pericarp
   2. Syncarpous pistil and Apocarpous pistil
   3. Plumule and Radicle

Expand and explain the following techniques used in the ‘Test Tube Baby’ programme :

1. GIFT
2. ZIFT
3. IUI

Name and explain a surgical contraceptive method that can be adopted by the male partner of a couple.

Suggest a suitable contraceptive device for the following cases with justification.

1. Mohini does not want to take the risk of conception and sexually transmitted infections (STIs).
2. Lalita has two children and does not want any more children.
3. Geeta wants a contraceptive that she can take till she wants to avoid conception and can resume back to her fertile life without the intervention of the doctor. Also, it should have a lower failure rate.

A couple, A and B, visit a fertility clinic. Examination reveals that female A has a blockage in her fallopian tubes, but her ovaries can produce viable ova. Male B produces sperm with a very low sperm count, making natural fertilization unlikely.

Which two different Assisted Reproductive Technologies (ARTs) would a doctor most likely recommend for this couple to increase their chances of conceiving? Justify your selection by briefly stating the principle behind each chosen technique concerning the couple's specific issues.

In the following figure, two ways of pairing of two homologous pairs of chromosomes are shown. Which of the following phenomena is expressed ?

1. Linkage of genes
2. Independent assortment of genes
3. Multiple alleles
4. Incomplete dominance

In a dihybrid cross, 2400 individuals are produced in F₂ generation. Approximately how many will be phenotypically similar to parents ?

1. 2000
2. 1500
3. 580
4. 450

The smallest part of DNA molecule that can be changed by point mutation is :

1. Oligonucleotide
2. Codon
3. Gene
4. Nucleotide

Select the correct statement. All genes located on the same chromosome :

1. form different groups depending upon their relative distance.
2. form one linkage group.
3. will not form linkage groups.
4. form interactive groups that affect the phenotype.

Assertion (A): The human blood group ‘AB’ exemplifies co-dominance.

Reason (R): The gene for human blood group trait exists in three allelic forms I^A, I^B and i.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

In Pisum sativum, the flower colour may be violet (V) or white (v). What proportion of the offspring in a cross of ‘VV’ × ‘vv’ would be expected to be violet ?

1. 25%
2. 50%
3. 75%
4. 100%

Morgan hybridised Drosophila white-eyed and yellow-bodied female with red-eyed and brown-bodied male (wild type) and intercrossed their F₁ progeny. He observed that the two genes :

1. Did not segregate independent of each other.
2. Showed very low percentage of parental gene combinations.
3. Segregated independently of each other.
4. Showed very high percentage of recombinations.

A man whose father was colour-blind marries a woman who had a colour-blind mother and normal father. What percentage of male children of this couple will be colour-blind ?

1. 25%
2. 0%
3. 50%
4. 75%

Assertion (A): When the two genes in a dihybrid cross are situated on the same chromosome, the proportion of parental gene combinations is much higher than non-parental type.

Reason (R): Higher parental gene combinations can be attributed to crossing over between two genes.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.

A child with blood group A has father with blood group B and the mother with blood group AB. Choose the option that gives the correct genotypes of father, mother and the child :

1. Father: I^Ai; Mother: I^Bi; Child: I^Ai
2. Father: I^AI^B; Mother: I^Ai; Child: I^AI^A
3. Father: I^Bi; Mother: I^AI^B; Child: I^Ai
4. Father: I^BI^B; Mother: I^AI^B; Child: I^AI^A

In a pedigree chart the symbol

represents :

1. unrelated mating
2. affected individuals
3. mating between relatives (consanguineous mating)
4. Non-identical twins

In the given pedigree chart, a cross between a normal couple resulted in a son who was haemophilic and a normal daughter. In course of time, when the daughter was married to a normal man, to their surprise the grandson was also haemophilic.

Choose the option that indicates the correct inheritance of trait in the above pedigree chart :

1. Autosome linked dominant trait
2. Sex-linked dominant trait
3. Autosomal recessive trait
4. Sex-linked recessive trait

In a pea plant (Pisum sativum) inflated pod shape is dominant over constricted pod shape. The expected ratio of phenotypes of the offspring in a cross between both the parents with heterozygous inflated pod shape will be :

1. 1 : 0
2. 1 : 1
3. 2 : 1
4. 3 : 1

Assertion (A): ABO blood grouping in humans is an example of multiple allelism.

Reason (R): More than two genes in a population govern the same character in ABO blood grouping in humans.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Which of the following is not an example of aneuploidy ?

1. Turner’s syndrome
2. Down’s syndrome
3. Phenylketonuria
4. Klinefelter’s syndrome

During a monohybrid cross involving a tall pea plant with a dwarf pea plant, the offspring populations were tall and dwarf in equal ratio. Find out the genotype of parent pea plants.

1. Tt × tt
2. TT × Tt
3. tt × tt
4. Tt × Tt

Assertion (A): Gene pairs present on the same chromosome may be tightly linked or loosely linked.

Reason (R): Frequency of recombination between gene pairs on different chromosomes as a measure of the distance between genes can be used for ‘mapping’ their position on the chromosomes.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Study the pedigree chart of a family sharing the inheritance of sickle cell anemia.

The trait traced in the above pedigree chart is :

1. Dominant X-linked
2. Autosomal dominant
3. Recessive X-linked
4. Autosomal recessive

Which of the following do not follow the law of independent assortment ?

1. Genes on non-homologous chromosomes and absence of linkage
2. Two or more genes on homologous chromosomes
3. Linked genes located on the same chromosomes
4. Two or more distant genes present on the same chromosome

Assertion (A): In dihybrid crosses involving sex-linked genes in Drosophila generation of non-parental gene combinations are observed.

Reason (R): Two genes present on different chromosomes show linkage and recombination in Drosophila.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Which of the following conditions correctly describes the manner of determining the sex in the given options ?

1. Homozygous sex chromosomes (ZZ) determine female sex in birds.
2. XO type of chromosomes determine male sex in grasshoppers.
3. XO condition in humans determines female sex.
4. Homozygous sex chromosomes (XX) produce male in Drosophila.

Assertion (A): A male individual always inherits haemophilia from his mother.

Reason (R): The gene for haemophilia lies on X-chromosome.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

A man with a certain disease marries a normal woman. They have four children (three daughters and one son). All the daughters suffer from their father’s disease but the son is not affected. Which of the following mode of inheritance do you suggest for this disease ?

1. Autosome Linked Recessive
2. Sex-linked Dominant
3. Autosome Linked Dominant
4. Sex-linked Recessive

What would be the genotype of parents if the F₁ offspring have the phenotypes in 1 : 1 proportion ?

1. Aa × Aa
2. AA × AA
3. Aa × AA
4. Aa × aa

Which of the following animals exhibit male heterogamety ?

1. Fruit fly
2. Fowl
3. Human
4. Honey bee

1. (i) and (iii)
2. (ii) and (iv)
3. (ii) and (iii)
4. (i) and (iv)

Select the incorrect match from the following :

Assertion (A): Linked genes do not show dihybrid F₂ ratio 9 : 3 : 3 : 1.

Reason (R): Linked genes do not undergo independent assortment.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Match the items in Column I with those in Column II and select the correctly matched option from those given below :

Options :

1. 1 (ii), 2 (iv), 3 (i), 4 (iii)
2. 1 (iii), 2 (i), 3 (iv), 4 (ii)
3. 1 (iii), 2 (iv), 3 (i), 4 (ii)
4. 1 (ii), 2 (i), 3 (iv), 4 (iii)

A woman with normal vision has a colour blind father. She marries a man with normal vision. The percentage chance of their progeny being colour blind is :

1. 25%
2. 50%
3. 75%
4. 100%

A Snapdragon plant bearing pink colour flowers is crossed with a Snapdragon plant bearing white colour flowers. The expected phenotypic percentage of the offspring is :

1. 50% Red : 50% White
2. 25% Red : 50% Pink : 25% White
3. 50% Pink : 50% White
4. 25% Pink : 50% Red : 25% White

In which of the given chromosomal disorders does the individual have tall stature with feminised character ?

1. Klinefelter’s syndrome
2. Down’s syndrome
3. Turner’s syndrome
4. Edwards’ syndrome

Identify the category of genetic disorder depicted in the pedigree chart given below :

1. X-Linked recessive
2. X-Linked dominant
3. Autosomal recessive
4. Autosomal dominant

Turner’s syndrome in humans occurs due to

1. Aneuploidy
2. Euploidy
3. Polyploidy
4. Autosomal abnormality

A single gene that controls the expression of more than one trait is said to show

1. Multiple allelism
2. Polygenic inheritance
3. Incomplete dominance
4. Pleiotropism

A person with trisomy of 21^st chromosome shows

1. Furrowed tongue
2. Characteristic palm crease
3. Rudimentary ovaries
4. Gynaecomastia

Select the correct option, from the choices given below :

1. (ii) and (iv)
2. (i), (ii) and (iv)
3. (ii) and (iii)
4. (i) and (ii)

Study the pedigree chart of a family showing the inheritance pattern of a certain disorder. Select the option that correctly identifies the nature of the trait depicted in the pedigree chart.

1. Dominant X – linked
2. Recessive X – linked
3. Autosomal dominant
4. Autosomal recessive

If both the parents are carriers for thalassaemia, the chances of an afflicted child to be born to them is :

1. 25%
2. 50%
3. 75%
4. 100%

Assertion (A): In birds the sex of the offspring is determined by males.

Reason (R): Males are homogametic while females are heterogametic.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.

In humans, non-disjunction of the 21st pair of chromosomes leads to :

1. Acquired Immune Deficiency Syndrome
2. Klinefelter’s Syndrome
3. Turner’s Syndrome
4. Down’s Syndrome

Which one of the following processes results in the production of recombinants in future generations ?

1. Mutation
2. Independent assortment during meiosis I
3. Independent assortment during meiosis II
4. Crossing over of bivalents

1. (iv) only
2. (ii) and (iv)
3. (i), (ii) and (iii)
4. (i), (ii), (iii) and (iv)

Assertion (A): Birds like pigeon have heterogametic females whereas the males are homogametic.

Reason (R): In pigeons, females have Z and W sex chromosomes whereas males have ZZ sex chromosomes.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Choose the set of sex determining chromosomes that indicates the correct sex of the respective organism.

1. Homozygous sex chromosomes (ZZ) determine female sex in birds
2. XO type of sex chromosomes determine male sex in grasshoppers
3. XXY condition in humans, as found in Turner Syndrome, determines male sex
4. Homozygous sex chromosomes (XX) produce male sex in Drosophila

Assertion (A): In humans the genotype with all the dominant alleles (AABBCC) will have the darkest skin colour.

Reason (R): In a polygenic trait, phenotype reflects the contribution of each allele.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Assertion (A): In Thalassemia an abnormal myoglobin chain is synthesized due to a gene defect.

Reason (R): α-Thalassemia is controlled by genes HBA1 and HBA2 on chromosome 16.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.

When round yellow seed bearing heterozygous pea plant is selfed, the frequency of occurrence of RrYY genotype among the F₂ offsprings is :

1. 9/16
2. 3/16
3. 1/16
4. 2/16

In a pedigree analysis, the symbol shown below represents :

1. Unrelated mating
2. Affected individuals
3. Consanguineous mating
4. Non-identical twins

Albinism is known to be due to an autosomal recessive mutation. The first child of a couple with normal skin pigmentation was an albino. What is the probability that their second child will also be an albino?

1. 100%
2. 25%
3. 50%
4. 75%

Study the given pedigree and identify the disease represented

1. Myotonic Dystrophy
2. Sickle cell anaemia
3. Haemophilia
4. Colour blindness

Assertion (A): There is no variation in the percentage recombination due to loosely or tightly linked genes.

Reason (R): Linked genes result in occurrence of higher proportion of parental gene combinations.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

(a) Analyse the following two cases of sex determination in different organisms :

Case I : Males have (XO) sex chromosomes and females have two copies of same sex chromosome (XX).

Case II : Females have two different sex chromosomes (ZW) and males have two copies of same sex chromosome (ZZ).

Identify the type of heterogamety in each case, giving one example of each.

OR

(b) (i) Differentiate between a DNA and RNA nucleotide.

(ii) Name the two types of bonds present within a single nucleotide.

(a) The diagram below shows the sequence of amino acids in part of haemoglobin molecule.

(i) If the base T* is substituted with A, in ‘CTT*’ of DNA strand how would it affect the haemoglobin chain ? [1]

(ii) Name the condition and the effects associated with the above substitution. [1]

OR

(b) DNA is considered a more stable genetic material than RNA. Justify this statement with suitable reasons.

What did Henking observe in his experiments on insects that led to the discovery of sex chromosome ? How did his observation contribute to our understanding of sex determination ?

Study the cross given below :

Identify the abnormalities ‘1’ and ‘2’ in the offsprings of a cross done between a couple and distinguish between them.

Study the pedigree chart given below, showing the inheritance pattern of blood group in a family :

Answer the following questions :

(a) Give the possible genotypes of individual 1 and 2.

(b) Which antigen or antigens will be present on the plasma membranes of the R.B.Cs of individuals ‘5’ and ‘8’ ?

Study the given pedigree chart in which neither of the parents shows the trait but the trait is present in both male and female children.

Answer the following questions :

(a) Write about the trait, also explain the inheritance of such trait in the progeny on the basis of given pedigree chart.

(b) Give one example of such trait in human beings.

A karyotype of a human suffering from a certain disorder is given below :

1. Identify the disorder.
2. Write the symptoms of the disorder.
3. Give reason for such a disorder.

(a) A couple believed that hospital authorities have exchanged babies and they have been given another baby by them. The wife is blood group ‘A’, her husband is blood group ‘B’ and the child is blood group ‘O’.

1. Could the baby be theirs ?
2. Justify your answer with the help of a cross.

OR

(b) Observe the diagram given below and answer the following questions.

1. Name the molecule ‘X’ synthesized by ‘i’ gene.
2. Which one of the structural genes codes for β-galactosidase ?
3. When will the transcription of this gene stop ?

Although Haemophilia and sickle cell anemia are two blood related Mendelian disorders, yet, they differ in their pattern of inheritance. State any two differences.

By using Punnett square depict the genotypes and phenotypes of test crosses (where green pod colour (G) is dominant over yellow pod colour (g)) in Garden pea with unknown genotype.

(a) What is pedigree analysis ? Mention its importance in human genetics. (2 pts.)

(b) Analyse the following pedigree and write the

(i) Pattern of inheritance.

(ii) Give one example of disease showing such an inheritance pattern.

(a) Give the scientific name of the organism used by Morgan to study sex-linked traits. [1]

(b) Write any four reasons why this organism made it an ideal experimental model. [2]

(a) Describe the experiment conducted by T.H. Morgan on Drosophila melanogaster involving eye colour and body colour. [1]

(b) How did the results deviate from Mendelian inheritance pattern ? [1]

(c) Explain the two genetic terms used by Morgan for his observations. [1]

Define test cross. How does test cross help to determine the genotype of an individual ? Explain with the help of an example.

Using a Punnett square workout the distribution of an autosomal phenotypic feature in the first filial generation after a cross between a homozygous female and a heterozygous male for a single locus.

Gregor Mendel conducted hybridisation experiments in garden pea for seven years and proposed the law of inheritance.

1. Why was he successful in his hybridisation experiments ? Give two reasons.
2. State the law of independent assortment as proposed by Mendel after his dihybrid crosses.

During a medical investigation, an infant was found to possess an extra copy of chromosome no. 21. Identify the disorder the child is suffering from. Describe the symptoms the child is likely to develop later in life.

Study the diagram above and answer the following questions :

1. How many alleles are involved in blood grouping ?
2. A person having ‘AB’ blood group has both dominant alleles. What is this inheritance type called ?
3. A man with ‘A’ blood group marries a woman with ‘B’ blood group. Can they have a child with ‘O’ blood group ? Explain with the help of a cross.

Answer the following questions with respect to the sex determining mechanism observed in honey bee.

1. Name the type of sex determination system observed in honey bee.
2. Fill in the blanks (i), (ii) and (iii) in the given question.

   Parent	Male
   Type of cell division involved during gamete formation in males	(i) ____________
   Number of chromosomes in the gametes	(ii) ____________
   Number of chromosomes in the diploid cell of the progeny	(iii) ____________

3. What will be the sex and chromosome number of the progeny formed from the unfertilised eggs of honey bee ?

In a family, the father, the daughter and the son are colour blind, whereas the mother has normal vision. Do you think the son and the daughter have inherited the disease from their father ? Work out a cross to justify your answer.

(a) (i) Write the karyotype and the genetic disorder of an individual who has developed from a zygote formed from an ‘XX’ egg fertilised by a ‘Y’ sperm.

(ii) Mention any two symptoms of this genetic disorder.

(iii) Write the possible reason that leads to the formation of this ‘XX’ egg.

OR

(b) In case of any dispute, a very small sample of tissue or even a drop of blood can help us to determine the paternity of a child. Provide a scientific explanation to substantiate the statement.

Three crosses were carried out in pea plants with respect to flower colour violet/white (V/v) and flower position axial/terminal (A/a). Study in the table the crosses ‘a’, ‘b’ and ‘c’ where parental phenotypes and their F₁ progeny phenotypes are given.

Find the genotypes of each of the parental pairs of crosses ‘a’, ‘b’ and ‘c’.

1. A man with blood group ‘A’ marries a woman with blood group ‘AB’. The first child born to them has blood group ‘B’. Work out a cross to find the genotype of the father. Give the possible blood groups and their genotypes of the children that could be born to this couple. (Use a Punnet square).
2. State the basis of ‘ABO’ blood grouping in humans.

Given below is the pedigree chart up to 3 generations (Generation I, Generation II, Generation III) of a family with respect to their blood groups.

(a) Mention the blood group along with the genotype of the offspring numbered ‘1’ in Generation II.

(b) Write the possible blood groups along with their genotypes of the offsprings numbered ‘2’ and ‘3’ in Generation III.

Study the given pedigree chart and answer the questions that follow.

1. Is the trait given in the chart dominant or recessive ? Give reason in support of your answer.
2. Is this trait autosomal or sex-linked ? Give reason in support of your answer.
3. Write the possible genotypes of the children numbers ‘1’ and ‘3’ of the second generation.

(a) The male fruit fly and female fowl are heterogametic, whereas female fruit fly and male fowl are homogametic. Explain.

(b) Male honey bees do not have a father and hence no sons, but can have a grandfather and grandson. Justify.

In guinea pigs, black coat colour (G) dominates over white (g) and brown eyes (B) dominate over blue (b). The alleles for coat colour and eye colour are not linked. What will be the probability of the offspring having blue eyes and a white coat if both parents are heterozygous for eye and coat colour? Find the probability using a Punnett square.

In mice, the traits for running ability and hair colour assort independently. Running (R) is dominant over walking in circles (r). Black hair (B) is dominant over brown hair (b). A heterozygous running, brown-haired female mouse was artificially inseminated using sperm from a heterozygous running, heterozygous black male.

1. Write the genotypes of both parents and draw a Punnett square showing all possible offspring combinations. (1)
2. Using the Punnett square, state the phenotypic ratio for: Running–Black, Running–Brown, Walking–Black, Walking–Brown. (1)
3. If 64 offspring were produced, calculate how many would be expected to show the Running–Black phenotype. (1)

How can a single gene defect caused by the mutation result in Phenylketonuria (PKU)? Explain the molecular mechanism underlying pleiotropy.

A student performed some crosses in plants and represented the result in the form of bar graphs as shown below. Each graph displays the phenotypic proportion of the progeny. Study the graphs and answer the questions :

(a) What can you infer about the genotype of parents in crosses I and II ?

OR

(a) Which genetic cross is represented by these crosses ?

(b) Looking at bar graph of cross III, identify the type of cross performed and its importance in genetics.

(c) What conclusion can you draw from the results of bar graphs of crosses I and II ? Name the genetic principle illustrated.

Read the following passage and answer the questions that follow :

Haemophilia is a sex-linked recessive disease. Study the pedigree analysis given below showing the inheritance of the disease in a family and answer the questions that follow :

(a) Analyse the given pedigree chart to explain why Haemophilia is considered a sex-linked recessive disorder.

(b) (i) The possibility of a human female becoming a haemophilic is extremely rare. Explain.

(ii) Why do the sons of a haemophilic father never suffer from this disease ?

(c) (i) Write the possible genotype of the individuals 2 and 5.

OR

(c) (ii) Why is haemophilia categorised as a Mendelian disorder ?

Read the following passage and answer the questions that follow.

The chromosome number is fixed for all normal organisms leading to species specification, whereas any abnormality in the chromosome number of an organism results into abnormal individuals. Sometimes an error may occur during meiosis of cell cycle, where the sister chromatids fail to segregate, called non-disjunction, leading to the production of abnormal gametes with altered chromosome number. On fertilization, such gametes develop into abnormal individuals.

(a) State what is aneuploidy.

(b) A normal human sperm (22 + Y) fertilizes an ovum with karyotype (22 + XX). Name the disorder of the offspring thus produced and write any two symptoms of the disorder.

(c) (i) What is meant by trisomy ? Mention the chromosome number that shows trisomy in Down’s syndrome.

OR

(c) (ii) Write any two symptoms of Down’s syndrome.

The following pedigree chart shows the inheritance of a genetic disorder up to three generations of a family. Observe the chart and answer the questions that follow.

1. Is the disease sex-linked or autosomal as per the chart ? Give reasons in support of your answer.
2. Is it a recessive or a dominant disorder ?
3. Write the genotypes of the individuals ‘C’, ‘D’ and ‘H’.
4. 1. If the female ‘D’ marries a normal man, what will be the probability of their daughter being a sufferer of this disease ?

   OR

   2. If the mother ‘B’ is a carrier of the disease, what will be the probability of their daughter being a sufferer of this disease ?

The chromosome number is fixed for all normal organisms leading to species specification whereas any abnormality in the chromosome number of an organism results into abnormal individuals. For example, in humans 46 is the fixed number of chromosomes both in male and female. In male it is ‘44 + XY’ and in female it is ‘44 + XX’. Thus the human male is heterogametic, in other words produces two different types of gametes one with ‘22 + X’ chromosomes and the other with ‘22 + Y’ chromosomes respectively. Human female, on the other hand, is homogametic i.e. produces only one type of gamete with ‘22 + X’ chromosomes only.

Sometimes an error may occur during meiosis of cell cycle, where the sister chromatids fail to segregate called nondisjunction, leading to the production of abnormal gametes with altered chromosome number. On fertilisation such gametes develop into abnormal individuals.

1. State what is aneuploidy.
2. If during spermatogenesis, the chromatids of sex chromosomes fail to segregate during meiosis, write only the different types of gametes with altered chromosome number that could possibly be produced.
3. A normal human sperm (22 + Y) fertilises an ovum with karyotype ‘22 + XX’. Name the disorder the offspring thus produced would suffer from and write any two symptoms of the disorder.

OR

3. Name a best known and most common autosomal aneuploid abnormality in human and write any two symptoms.

(a) Write the types and locations of the genes causing thalassemia in humans. State the cause and symptoms of the disease. How is sickle-cell anemia different from this disease ?

OR

(b) (i) Enlist any four prime goals of the Human Genome Project (HGP).

(ii) List the two methodologies which were involved in the human genome project. Mention how they were used.

(iii) Expand ‘YAC’ and mention what it was used for.

(a) Work out separate monohybrid crosses up to F₂ generation between two pea plants and two Antirrhinum plants, both having contrasting traits with respect to the colour of the flower. Comment on the patterns of inheritance in the crosses carried out in such two cases.

OR

(b) Answer the following questions : [2+3 = 5]

(i) How does a chromosomal disorder differ from a Mendelian disorder ? Write one example for each.

(ii) Name the phenomenon that leads to situations like ‘XO’ abnormality in humans. Also name this genetic disorder. How are individuals with an XO chromosomal abnormality affected ? Write its symptoms as well as karyotype.

Student to attempt either option-(A) or (B) :

(A) (i) Perform a cross between two sickle cell carriers. What ratio is obtained between carrier, disease free and diseased individuals in F₁ progeny ? Name the nitrogenous base substituted, in the haemoglobin molecule in this disease.

(ii) Explain the difference in inheritance pattern of flower colour in garden pea plant and snap-dragon plant with the help of monohybrid crosses.

OR

(B) Explain with the help of well-labelled diagrams how lac operon operates in E. coli :

1. In presence of an inducer.
2. In absence of an inducer.

(a) (i) Compare the pattern of inheritance of flower colour in garden pea plant (violet/white) with snapdragon plant (red/white) on the basis of the following :

1. F₁ phenotypic expression;
2. expected phenotypic and genotypic expression of F₂ generation;
3. the conclusion you reached at the end of the comparison made.

(ii) List any two characteristics of pattern of inheritance of human blood group ABO.

OR

(b) (i) Draw a schematic, self-explanatory labelled diagram of lac operon in ‘switched on’ condition.

(ii) Why is regulation of lac operon referred to as negative regulation ?

1. “The influence of both the alleles in a heterozygous state is clearly expressed in codominance.” Explain with the help of inheritance of ABO blood group in humans.

OR

2. “A group of genes are regulated and expressed together as a unit in lac operon.”
   1. Explain the mechanism of switching ‘on’ of the structural genes of lac operon.
   2. “Regulation of ‘lac operon’ is referred to be negatively regulated.” Justify giving a reason.

(a) Work out a monohybrid cross up to F₂ generation (1) between two pea plants (2) between two Antirrhinum plants, both having contrasting traits with respect to colour of the flower. Comment on their pattern of inheritance.

OR

(b) (i) Expand hnRNA. Name the type of cells and the enzyme that transcribes it.

(ii) Is it a precursor ? Explain the process that it undergoes to become a functional molecule. Name this molecule.

(iii) Differentiate between mRNA and tRNA with respect to their roles in the cells.

To separate repetitive DNA from bulk genomic DNA, which of the following method is used ?

1. Elution
2. Southern Blotting
3. Polymerase Chain Reaction
4. Density Gradient Centrifugation

A bacterium having radioactive thymidine in its DNA is allowed to multiply in a medium having non-radioactive thymidine for two generations. What percentage of bacteria will have radioactive thymidine in its DNA ?

1. 100
2. 50
3. 75
4. 25

Four different transcription units are shown below. Choose the option with the correct image.

Options (A)–(D) are shown in the figure.

Assertion (A): Repetitive sequences are stretches of DNA sequences that are thought to have no direct coding functions.

Reason (R): They shed light on chromosome structure, dynamics and evolution.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Choose the correct statements :