Biology (Science 086) · Class X · Chapter-wise Board Questions

Which structure in a leaf is mainly responsible for gaseous exchange ?

1. Xylem
2. Stomata
3. Phloem
4. Cuticle

Pancreas secretes pancreatic juice which contain certain enzyme that helps in digestion of food.

Choose the correct option from the following :

1. Trypsin digests emulsified fats and lipase digests proteins.
2. Trypsin digests proteins and lipase digests emulsified fats.
3. Trypsin and lipase both digests fats.
4. Trypsin digests proteins and lipase digests carbohydrates.

Directions: Questions 8 and 9 are Assertion and Reason based questions. Select the correct answer from the codes (A), (B), (C) and (D) as given below.

Assertion (A) : In human beings, the respiratory pigment is haemoglobin present in red blood cells.

Reason (R) : Haemoglobin has a very high affinity for carbon dioxide.

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 carbohydrates, which are not used immediately in plants, are stored in the form of ‘a’, which serves as an internal energy reserve. What does ‘a’ stand for ?

1. Starch
2. Sugar
3. Fat
4. Protein

The following events occur during the process of photosynthesis. Choose the option that indicates the correct events.

(i) Oxidation of carbon dioxide to carbohydrates

(ii) Conversion of light energy into chemical energy

(iii) Absorption of light energy by chlorophyll

(iv) Conversion of hydrogen and oxygen into water

Options :

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

Assertion (A) : Blood plasma transports carbon dioxide in dissolved form, while oxygen is transported by respiratory pigments.

Reason (R) : Carbon dioxide is more soluble in water than in oxygen.

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.

Pravin was given a list of characteristics associated with the process of anaerobic respiration in humans, in the table given below :

Which of the above characteristics is/are related to the above process ?

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

Observe the figure given below and identify the incorrect step for the activity set-up :

1. Both plants are kept in the dark room for three days before placing them in separate glass jars.
2. Both plants are covered with separate wooden bell-jars.
3. Use vaseline to seal the bottom of the jars with the glass plates.
4. Both potted plants were kept in sunlight for a few hours before the iodine test for the presence of starch.

Assertion (A) : The basic filtration unit in the kidneys, like in the lungs, is a cluster of very thin-walled blood capillaries.

Reason (R) : Each capillary cluster in the kidney is associated with the cup-shaped end of a coiled tube called Bowman’s capsule.

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.

Observe the given figure and select the statement that correctly states how these fungi obtain nutrition.

1. By eating the bread on which it is growing.
2. By using nutrients from the bread to prepare their own food.
3. By breaking down the nutrients of bread outside the body and then absorbing them.
4. By allowing other organisms to grow on the bread and then consuming them.

In human beings the oxygen rich blood is pumped out to the body by :

1. contraction of right atrium
2. relaxation of left ventricle
3. contraction of right ventricle
4. contraction of left ventricle

Identify the part that controls the closing and opening of the stomatal pore in leaves of plants.

Select the correct option.

1. Stomata
2. Epidermal cells
3. Guard cells
4. Chloroplasts

Choose the equation of reaction that correctly represents anaerobic respiration in muscles :

1. Glucose → Pyruvate → (absence of O₂) Ethanol + CO₂ + Energy
2. Glucose → (O₂) Pyruvate → (O₂) Energy
3. Glucose → (O₂) Pyruvate → (lack of oxygen) Ethanol + Energy
4. Glucose → Pyruvate → (lack of oxygen) Lactic acid + Energy

Assertion (A) : The peristaltic movements occur all along the gut.

Reason (R) : The lining of the gut has muscles that contract rhythmically to push the food in regulated manner.

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.

Name the enzyme that acts on the protein-rich diet inside our stomach :

1. Pepsin
2. Amylase
3. Trypsin
4. Lipase

Which of the following is not a function of transpiration ?

1. It helps in regulation of temperature.
2. It helps in upward movement of water.
3. It transports food to different parts of the plant body.
4. It helps in movement of minerals from the roots to the leaves.

Which of the following options is not a step in the process of photosynthesis ?

1. Absorption of light energy by chlorophyll
2. Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen
3. Reduction of carbon dioxide to carbohydrates
4. Storage of food in roots and stems

Directions: For Questions 8 and 9, two statements are given - one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer from the codes (A), (B), (C) and (D) as given below.

Assertion (A) : Walls of the ventricles are thicker than those of the atria.

Reason (R) : Thick walls of the ventricles help in preventing the backflow of blood.

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.

Select the correct option that shows the path of flow of only the deoxygenated blood through the human circulatory system.

1. Body → left atrium → left ventricle → lungs → right atrium → right ventricle → body.
2. Right atrium → right ventricle → lungs → left atrium → left ventricle → body
3. Body → left atrium → left ventricle → lungs
4. Body → right atrium → right ventricle → lungs

Which of the following groups consists entirely of substances that are broken down by an enzyme, lipase ?

1. Carbohydrates, proteins and vitamins
2. Fats, oils and ghee
3. Minerals, starch and vitamins
4. Proteins, sugars and esters

During the process of exhalation, air follows a definite path from lungs to outside.

Choose the correct option showing the path of exhaled air.

1. Alveoli → Trachea → Larynx → Pharynx → Nostril
2. Nasal cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles
3. Body tissue → Blood → Lungs → Nose
4. Alveoli → Trachea → Pharynx → Larynx → Nostril

Secretion of less saliva in mouth will effect the conversion of :

1. proteins into amino acids
2. fats into fatty acids and glycerol
3. starch into simple sugars
4. sugars into alcohol

The breakdown of glucose has taken the following pathway :

Glucose →(a) Pyruvate + Energy →(b) Lactic acid + Energy

The sites ‘a’ and ‘b’ respectively are :

1. Mitochondria and Oxygen deficient muscle cells
2. Cytoplasm and Oxygen rich muscle cells
3. Cytoplasm and Yeast cells
4. Cytoplasm and Oxygen deficient muscle cells

The opening and closing of stomata is regulated by :

1. CO₂ concentration in stomata
2. Temperature in guard cells
3. O₂ concentration in stomata
4. Amount of water in guard cells

One-cell thick blood vessels are known as :

1. Alveoli
2. Capillaries
3. Arteries
4. Veins

Assertion (A) : Animals will not get energy if they eat (consume) coal as food.

Reason (R) : Specific enzymes are needed for the breakdown of a particular food.

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.

The gastric glands present in the wall of the stomach release :

1. Mucus and Trypsin
2. Pepsin and Trypsin
3. Mucus and Pepsin
4. Pepsin and Salivary amylase

The essential element taken up from the soil by the plants to synthesize proteins is :

1. Phosphorus
2. Nitrogen
3. Iron
4. Magnesium

Select TRUE statements about lymph from the following :

A. Lymph vessels carry lymph through the body and finally open into larger arteries.

B. Lymph contains some amount of plasma, proteins and blood cells.

C. Lymph contains some amount of plasma, proteins and red blood cells.

D. Lymph vessels carry lymph through the body and finally open into larger veins.

The true statements are :

1. A and B
2. B and D
3. A and C
4. C and D

Assertion (A) : In large animals, oxygen can reach different parts of the animal's body easily.

Reason (R) : Respiratory pigments take up oxygen from the air and carry it to body tissues.

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, and 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.

Listed below are the steps of nutrition in Amoeba. Select the correct sequence of these steps :

(i) Diffusion of simple nutrients into cytoplasm

(ii) Food vacuole formation

(iii) Formation of finger like temporary extensions of cell surface

(iv) Complex substances broken to simpler ones

(v) Undigested material thrown out of the cell surface

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

In aerobic respiration, the steps are : breakdown of glucose to pyruvate and its further conversion to carbon dioxide. Both processes respectively occur in -

1. Vacuole and Cytoplasm
2. Chloroplast and Mitochondria
3. Mitochondria and Cytoplasm
4. Cytoplasm and Mitochondria

The basic filtration unit of the excretory system in human beings is :

1. Nephron
2. Urethra
3. Neuron
4. Urinary bladder

In human alimentary canal, the digestive juice secreted by the gastric glands are

1. Bile, Trypsin, Pepsin
2. Hydrochloric acid, Pepsin, Mucus
3. Lipase, Bile, Mucus
4. Salivary amylase, Pepsin, Bile

Assertion (A) : Xylem tissue moves water and minerals obtained from the soil by the roots.

Reason (R) : Xylem tissue is found only in the roots of a plant.

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, and 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.

The valves in the human heart ensure that :

(i) Oxygen-rich blood flows from left atrium to left ventricle only.

(ii) Deoxygenated blood flows from left atrium to left ventricle only.

(iii) Oxygen-rich blood flows from right atrium to right ventricle only.

(iv) Deoxygenated blood flows from right atrium to right ventricle only.

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

Assertion (A) : Transpirational pull helps in the absorption and upward movement of water and dissolved minerals in plants.

Reason (R) : The effect of root pressure in transport of water is more significant at night.

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.

A stomata closes when :

(i) it needs carbon dioxide for photosynthesis.

(ii) it does not need carbon dioxide for photosynthesis.

(iii) water flows out of the guard cells.

(iv) water flows into the guard cells.

The correct reason(s) in this process is/are :

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

Assertion (A) : The rate of breathing in aquatic organisms is much faster than in terrestrial organisms.

Reason (R) : The amount of oxygen dissolved in water is very high as compared to the amount of oxygen in air.

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 statement(s) is (are) true about human heart ?

(a) Right atrium receives oxygenated blood from lungs through pulmonary artery.

(b) Left atrium transfers oxygenated blood to left ventricle which sends it to various parts of the body.

(c) Right atrium receives deoxygenated blood through vena cava from upper and lower body.

(d) Left atrium transfers oxygenated blood to aorta which sends it to different parts of the body.

1. (a)
2. (a) and (d)
3. (b) and (c)
4. (b) and (d)

In human respiratory system, when a person breathes in, the position of ribs and diaphragm will be :

1. lifted ribs and curve/dome shaped diaphragm.
2. lifted ribs and flattened diaphragm.
3. relaxed ribs and flattened diaphragm.
4. relaxed ribs and curve/dome shaped diaphragm

Which of the following statement (s) is (are) true about human heart ?

(a) Right atrium receives oxygenated blood from lungs through pulmonary artery.

(b) Left atrium transfers oxygenated blood to left ventricle which sends it to various parts of the body.

(c) Right atrium receives deoxygenated blood from different parts of the body through vena cava.

(d) Left atrium transfers oxygenated blood to aorta which sends it to different parts of the body.

1. (b) only
2. (a) and (d)
3. (b) and (c)
4. (b) and (d)

In human beings, when the process of digestion is completed, the (i) proteins, (ii) carbohydrates, and (iii) fats are respectively finally converted into :

1. (i) Amino acids, (ii) glucose and (iii) fatty acids
2. (i) Amino acids, (ii) glucose, (iii) fatty acids and glycerol
3. (i) Glucose, (ii) fatty acids and glycerol, (iii) amino acids
4. (i) Sugars, (ii) amino acids, (iii) fatty acids and glycerol

Assertion (A) : In the human heart ventricles have thicker muscular walls than atria.

Reason (R) : Ventricles have to pump the blood into various organs.

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.

The process in which transport of soluble products of photosynthesis takes place in plants is known as :

1. Transpiration
2. Evaporation
3. Conduction
4. Translocation

In the human respiratory system, the path taken by air when we breathe in is :

1. Nostrils → Larynx → Trachea → Pharynx → Alveoli
2. Nostrils → Trachea → Larynx → Pharynx → Alveoli
3. Nostrils → Pharynx → Larynx → Trachea → Alveoli
4. Nostrils → Larynx → Pharynx → Trachea → Alveoli

In plants, waste products like resins and gums are stored in :

1. leaves that fall off
2. old xylem
3. phloem
4. cellular vacuoles

An organism which breaks down the food material outside the body and then absorbs it is

1. a plant parasite, Cuscuta
2. an animal parasite, Tapeworm
3. a bacteria, Rhizobium
4. a fungi, Rhizopus

Consider the following statements about small intestine and select the one which is NOT correct :

1. The length of the small intestine in animals differs as it depends on the type of food they eat.
2. The small intestine is the site of complete digestion of food.
3. The small intestine receives secretions from liver and pancreas.
4. The villi of the small intestine absorb water from the unabsorbed food before it gets removed from the body via the anus.

Assertion (A) : Blood clotting prevents excessive loss of blood.

Reason (R) : Blood clotting is due to blood plasma and white blood cells present in the blood.

Select the correct answer from the options given below.

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.

Sphincter muscles are present at the exit of :

1. Stomach and small intestine
2. Stomach and anus
3. Small intestine and large intestine
4. Oesophagus and stomach

In the following diagram, identify the cells through which massive amounts of gaseous exchange takes place for photosynthesis :

1. I
2. IV
3. III
4. II

During vigorous exercise, the occurrence of cramps in the outer muscles of an athlete is due to the conversion of pyruvate to :

1. Glucose
2. Ethanol
3. Lactic acid
4. Lactose

Observe the following diagram and identify the process and its significance from the following options :

1. Evaporation : maintains water contents in leaf cells.
2. Transpiration : creates a suction force which pulls water inside the plant.
3. Excretion : helps in excreting out waste water from the plant.
4. Translocation : helps in transporting materials from one cell to another.

Opening and closing of stomata is due to :

1. High pressure of gases inside the cells.
2. Movement of water in and out of the guard cells.
3. Stimulus of light in the guard cells.
4. Diffusion of CO₂ in and out of the guard cells.

Assertion (A) : The inner walls of the small intestine have finger like projections called villi which are rich in blood.

Reason (R) : These villi have a large surface area to help the small intestine in completing the digestion of food.

Select the correct answer from the codes (a), (b), (c) and (d) given below.

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.

The process in which loss of water in the form of vapours from the aerial parts of plants takes place is X, which helps in Y. Here X and Y respectively are :

1. transpiration and photosynthesis.
2. transpiration and temperature regulation.
3. translocation and movement of soluble products of photosynthesis in phloem.
4. translocation and absorption of water and minerals from soil by roots.

As compared to terrestrial organisms, the rate of breathing in aquatic organisms is :

1. faster because they need more oxygen for their survival.
2. faster because the amount of dissolved oxygen in water is fairly low.
3. slower because the amount of dissolved oxygen in water is fairly low.
4. slower because the capacity of water of dissolving atmospheric air is limited.

Assertion (A) : The walls of atria are thicker than those of the ventricles.

Reason (R) : Ventricles have to pump blood into various organs at high pressure.

Select the correct answer from the codes (a), (b), (c) and (d) given below.

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 the given diagram of a closed stomata : (1), (2), (3) and (4) respectively are

1. nucleus, chloroplast, guard cell, vacuole
2. nucleus, chloroplast, vacuole, guard cell
3. chloroplast, nucleus, vacuole, guard cell
4. vacuole, guard cell, nucleus, chloroplast

Assertion (A) : Amoeba takes in food using finger like extensions of the cell surface.

Reason (R) : In all unicellular organisms, the food is taken in by the entire cell surface.

Select the correct answer from the options given below.

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

Which one of the following molecules is produced initially when glucose breaks down in the cytoplasm of a cell in aerobic as well as anaerobic respiration ?

1. Lactic acid
2. Ethanol
3. Carbon dioxide
4. Pyruvate

As compared to daytime, the amount of carbon dioxide released by the plants during night is more because :

1. It is not produced during daytime.
2. It is stored in the leaves of plants during daytime.
3. Major amount of carbon dioxide produced is used up for photosynthesis during daytime.
4. Plants do not respire during daytime.

Select the group in which all organisms have the same mode of nutrition.

1. Cuscuta, yeast, legumes, leeches and tapeworm
2. Cactus, ticks, lice, leeches and cow
3. Cuscuta, ticks, lice, leeches and tapeworm
4. Cactus, grass, lice, lion and tapeworm

Which of the following options indicates the products formed after breakdown of the glucose in our muscle cells when there is lack of oxygen?

1. Ethanol + carbon dioxide + Energy
2. Lactic acid + Energy
3. Lactic acid + carbon monoxide + Energy
4. Carbon dioxide + Water + Energy

During photosynthesis, what happens to carbon dioxide and water as glucose is formed?

1. Carbon dioxide gains hydrogen, while water loses electrons.
2. Carbon dioxide loses oxygen, while water gains oxygen.
3. Carbon dioxide is oxidised, while water is reduced.
4. Both carbon dioxide and water undergo reduction.

Lime water turns cloudy in the presence of a gas, which is a by-product of respiration. Shown below are four setups kept in sunlight for 24 hours. In which setup is lime water expected to be the cloudiest?

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

During urine formation, tubular reabsorption and secretion take place in the kidneys. Which of the following sets correctly indicates both the substances that are reabsorbed in the kidneys?

1. Glucose and salts
2. Glucose and starch
3. Glycogen and salts
4. Glycogen and starch

Assertion (A) : The rate of breathing in aquatic organisms is much lower than in the terrestrial organisms.

Reason (R) : The amount of oxygen dissolved in water is less as compared to the amount of oxygen in air.

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.

What is the function of diaphragm in human respiratory system ? Where is it present in human body ?

What kind of respiration provides more energy and why ?

Separation of right side and left side of the heart is useful to keep oxygenated and deoxygenated blood from mixing. Various organisms have different types of heart.

(I) Fill in the blanks (i) to (iii) correctly according to the type of organisms and their evolution in terms of blood circulation :

(II) Which type of circulation is most efficient ?

“Transpiration in plants is a necessary evil.” Comment on the statement giving two reasons.

Give a diagrammatic representation of nutrition in Amoeba.

Briefly mention the steps in double-circulation through human heart.

(A) How does translocation of food and other substances take place in plants ?

OR

(B) Explain mechanism of opening and closing of stomata in plants.

(a) Besides minimising the loss of blood, why is it essential to plug any leak in a blood vessel ? Name the component of blood which helps in this process and state how this component perform this function.

OR

(b) (i) The transport system in plants is relatively slower than in animals. Give reasons.

(ii) State the role of phloem in the transport of materials in plants.

State the main function of veins in human circulatory system. Why do they not need thick walls ?

“Plants use a variety of techniques to get rid of waste material.” Justify this statement giving any four ways.

(A) How is lymph formed ? State its important function.

OR

(B) (a) Identify ‘X’ in the figure of human nephron shown below. What role does it play in the process of urine formation ?

(b) Why some substances are selectively reabsorbed from the initial filtrate of urine, as it flows along the tubular part of nephron ?

Give reasons :

(a) During a breathing cycle, the lungs always contain a residual volume of air.

(b) As compared to oxygen, carbon dioxide is mostly transported in dissolved form in our blood.

State one role of each of the following in human digestive system :

(i) Hydrochloric acid

(ii) Villi

(iii) Anal Sphincter

(iv) Lipase

Photosynthesis takes place in the leaves and the food prepared by it reaches other parts of the plants. Name the process involved and explain it.

(a) We need to water the soil in plants on a regular basis. But it ultimately reaches the leaves of the plant. Explain how this takes place.

OR

(b) Name the type of nutrition exhibited by Amoeba. Explain how food is taken in and digested by this organism.

(a) Sometimes while running, the athletes suffer from muscle cramps. Why ? How is the respiration in this case different from aerobic respiration ?

OR

(b) Write the other name given to lymph. State its two functions.

(a) Name the type of blood (oxygenated / deoxygenated) transported by each of the following mentioning the path (i.e. from one organ (which place) to another (which place)).

(i) Vena cava

(ii) Pulmonary artery

OR

(b) With the help of a schematic flow chart, show the breakdown of glucose in a cell to provide energy –

(i) in the presence of oxygen

(ii) in lack of oxygen

Name the part of the human excretory system where nephrons are found. Write the structure and function of nephrons.

(a) Why is it important to prevent oxygenated and deoxygenated blood from mixing in birds and mammals ?

(b) Which animals can tolerate some mixing of the oxygenated and deoxygenated blood streams ? On what factor does the body temperature of these animals depend ?

Write one specific function each of the following organs in relation with excretion in human beings :

(i) Renal Artery

(ii) Urethra

(iii) Glomerulus

(iv) Tubular part of nephron

Two green plants are kept separately in oxygen free containers, one in the dark and other in sunlight. It was observed that plant kept in dark could not survive longer. Give reason for this observation.

(a) List the events in proper sequence that take place during the process of photosynthesis.

OR

(b) Explain in brief two ways by which leaves of a plant help in excretion.

In the process of digestion of food in human beings, two protein-digesting enzymes are secreted. Name the enzymes along with the glands that secrete them.

Give the name of the enzyme present in the fluid in our mouth cavity. State the gland which produces it. What would happen to the digestion process if this gland stops secreting this enzyme ?

Unlike animals, plants do not have any excretory products as they do not eat food. Comment upon the statement with justification.

Students to attempt either option A or B.

A. How many chambers are there in the heart of the following organisms? How is mixing of oxygenated and deoxygenated blood prevented in their body?

(i) Fishes

(ii) Humans

OR

B. Explain the mechanism by which the water is transported in plants?

A. Due to narrowing of the bile duct, the bile secretion from the liver to the small intestine was obstructed. How will the process of digestion be affected?

B. How does the length of the intestine depend on the nature of food habit in different animals?

Give differences between the following :

(a) Nephron and neuron

(b) Sensory nerve and motor nerve

(c) Consumers and decomposers

Complete the pathways given below, showing the breakdown of glucose.

Identify ‘A’, ‘B’, ‘C’, ‘D’, ‘E’ and ‘F’.

In xylem tissue, vessels and tracheids of the roots, stems and leaves are interconnected to form a continuous system of water-conducting channels reaching all parts of the plant. Explain how this is achieved.

During respiration, glucose is broken down into pyruvate. State the end products formed from it on further breakdown, in each of the following cases :

(a) In yeast, in absence of oxygen.

(b) Lack of oxygen in muscles.

(c) In presence of oxygen in mitochondria.

On the basis of the characteristics of the processes given in the brackets in each case, differentiate between the following :

(a) Products of breakdown of pyruvate in aerobic and anaerobic respiration in human beings (product(s) of the processes)

(b) Respiration and photosynthesis in plants (gas released)

(c) Respiration in terrestrial animals and fishes (organs involved)

The digestion of food in human alimentary canal is a complex process. State the enzyme/salt present in the following and mention their function in the process of digestion :

(i) Saliva

(ii) Bile Juice

(iii) Pancreatic Juice

(a) Write the name and one function of respiratory pigment found in human beings.

(b) Why do lungs always contain a residual volume of air ?

(c) Why is ATP known as energy currency of the living beings ?

Name the blood vessel that brings (i) oxygenated blood (ii) deoxygenated blood, to the human heart. Also name that chamber of the heart which receives deoxygenated blood and state how deoxygenated blood from this chamber is sent to lungs for oxygenation.

(a) Write the end products of the breakdown of pyruvate in yeast cells and in our muscle cells under anaerobic conditions.

(b) In which part of the cell does the above process take place ?

(a) Explain the process of translocation of food and other substances in the phloem of plants.

OR

(b) Differentiate between xylem and phloem on the basis of the following :

(i) Direction of transport of the substances

(ii) Major driving forces involved in the transport

(iii) Nature of the substance(s) transported

(i) Why is respiratory pigment needed in multicellular organisms with large body size ?

(ii) Give reasons for the following :

(a) Rings of cartilage are present in the throat.

(b) Lungs always contain a residual volume of air.

(c) The diaphragm flattens and ribs are lifted up when we breathe in.

(d) Walls of alveoli contain an extensive network of blood vessels.

(a) Give reasons for the following :

(i) Alveoli in lungs are richly supplied with blood capillaries.

(ii) Respiratory pigment in the blood takes up oxygen and not carbon dioxide.

(iii) During anaerobic respiration, a 3-carbon molecule is formed as an end product instead of CO₂ in human beings.

OR

(b) (i) Name the movements that occur all along the gut in human digestive system. How do they help in digestion ?

(ii) Where is bile juice stored in human body ? List two roles of bile juice.

We water the soil but it reaches the topmost leaves of the plants. Explain in brief the process involved.

(a) (i) State the role of ATP in cellular respiration.

(ii) What ensures sufficient exchange of gases in plants ?

(iii) State the conditions on which the direction of diffusion of gases in plant depend upon.

OR

(b) (i) What is the internal energy reserve in plants and animals ?

(ii) How desert plants perform photosynthesis if their stomata remain closed during the day ?

(a) (i) What is the first step in the breakdown of glucose during aerobic and anaerobic respiration ? Where does it take place ?

(ii) ATP is called the energy currency of the cell. Why ?

(iii) What is meant by residual volume of air in a breathing cycle ?

OR

(b) Write in sequence the steps for experimental verification of the fact that sunlight is essential for photosynthesis.

(A) (i) How does Paramecium obtain its food ?

(ii) List the role of each of the following in our digestive system :

(a) Hydrochloric acid   (b) Trypsin   (c) Muscular walls of stomach   (d) Salivary amylase

OR

(B) (i) What is double circulation ?

(ii) Why is the separation of the right side and the left side of the heart useful ? How does it help birds and mammals ?

(a) With the help of an activity, explain the action of saliva on the food we eat.

(b) Why is bile juice important in the process of digestion ?

Explain the process of transport of oxygenated and deoxygenated blood in a human body.

What is photosynthesis ? Name the organelle and the organs in which photosynthesis takes place. Where does the oxygen liberated come from during this process ? What happens to the carbohydrates which are not immediately used by the plant ?

(a) Give the structure and function of alveoli in human respiratory system.

(b) What is meant by residual volume of air in the lungs ?

Write any two ways by which plants obtain carbon dioxide. What causes the opening and closing of the stomata ?

Read the following passage and answer the questions that follow :

Not all plants carry out photosynthesis by the same mechanism. In most plants, it depends directly on gaseous carbon dioxide that diffuses into the leaf. However, some plants can store carbon dioxide in the vacuole of the leaf cells as part of a complex carbon compound. This compound is transported to the chloroplast and releases carbon dioxide when required for photosynthesis. This special mechanism is believed to have evolved as an adaptation in such plants which do not open stomata during the daytime to conserve water for survival in dry conditions (desert conditions).

Attempt either (a) or (b) :

(a) (i) Which process in these plants is minimised to help the plants survive in dry conditions ?

(ii) Which part of the leaf is responsible for exchange of gases during photosynthesis ?

OR

(b) (i) List the events that occur during the process of photosynthesis.

(ii) When are such desert plants likely to take in carbon dioxide from the environment, unlike other plants ?

(iii) Draw a labelled diagram of stomata with open stomatal pore.

Kidneys help to regulate the volume of fluid and various metabolites waste products in the body. Normally, kidney filter about 180 L of fluid daily but the volume actually excreted out is only a litre or two a day. Patients with kidney failures can be saved by dialysis and kidney transplant.

(a) Write the structure and function of Bowman’s capsule. [1]

(b) Although kidneys filter a large amount (about 180 L daily) of fluids, still the excretion from the body is only about a litre or two. Why ? [1]

(c) What is excretion ? Why is it necessary for any living organism ? [2]

OR

(c) State two similarities between lungs and kidneys. [2]

The given diagram shows the human kidney and its associated structures.

Study the Table I and Table II that shows the concentration of certain substances found within the structure P and Q.

Table I - Structure P

Table II - Structure Q

(A) Where are kidneys located in the human body ? Name the filtration unit of them. [1]

(B) List two factors on which reabsorption of water from the filtrate depends. [1]

(C) Why is there variation in the concentration of given substance in structure P and Q listed in table I and II respectively ? [2]

OR

(C) If a person is suffering from diabetes, concentration of which substance present in structure Q (listed in table II) will be modified and why ? [2]

The maintenance functions of all living organisms must go on even when they are not doing anything particular. Even when we are just sitting in a class or even asleep, this maintenance job has to go on. These maintenance processes require energy to prevent damage and break-down of cells and tissues, which is obtained by the individual organism from the food prepared by the autotrophs, called producers.

(a) Name and define the process by which green plants prepare food. [1]

(b) Write chemical equation involved in the above process. [1]

(c) (i) State in proper sequence the events that occur in synthesis of food by desert plants. [2]

OR

(c) (ii) Explain giving reasons what happens to the rate at which the green plants will prepare food (I) during cloudy weather, and (II) when stomata get blocked due to dust. [2]

Human digestive system is a tube running from mouth to anus. Its main function is to breakdown complex molecules present in the food which cannot be absorbed as such into smaller molecules. These molecules are absorbed across the walls of the tube and the absorbed food reaches each and every cell of the body where it is utilised for obtaining energy.

(a) Name the glands present in the buccal cavity and write the components of food on which the secretion of these glands act upon.

(b) Two organs have a sphincter muscle at their exit. Name them.

(c) What will happen if :

(i) mucus is not secreted by the gastric glands.

(ii) Villi are absent in the small intestine.

OR

(c) “Bile juice does not contain any enzyme, yet it has important roles in digestion.” Justify the statement.

Kidneys are vital organs for survival. Several factors like infections, injury or restricted blood flow to kidneys reduce the activity of kidneys. This leads to accumulation of poisonous wastes in the body, which can even lead to death. In case of kidney failure, an artificial kidney can be used. An artificial kidney is a device to remove waste products from the blood through dialysis.

(a) (i) Name the artery that brings oxygenated blood to the kidney.

(ii) Name the cluster the thin-walled blood capillaries present in the Bowman's capsule.

(b) In human excretory system name the organ which stores urine. Is this organ under hormonal control or nervous control ?

(c) (i) List two major steps involved in the formation of urine and state in brief their functions.

OR

(c) (ii) In which part of the nephron does selective reabsorption take place ? List the factors which the amount of water reabsorbed depends on.

Neha consumed boiled sweet potatoes and boiled eggs for breakfast. Help her to understand some steps in the process of digestion of the food taken by her by answering the questions given below.

Attempt either subpart A or B.

A. Which of these food items is rich in proteins? In which part of the alimentary canal is the digestion of this component initiated? Name the enzymes, conditions required and the glands associated with the digestion here.

OR

B. Which of these food items contains fats? How is it digested?

C. Which of these food items is rich in starch? How is its digestion initiated?

D. The figure given below represents parts of the human alimentary canal. Which of these parts will have the maximum amount of digested food as soon as the process of digestion is completed?

(A) (a) Draw a labelled diagram showing open and closed stomatal pore.

(b) List the main events that occur during the process of photosynthesis.

(c) Write a balanced chemical equation showing photosynthesis in plants.

OR

(B) (a) Draw a well-labelled diagram of nephron and label atleast 4 of its parts.

(b) Write the role of capillary cluster inside Bowman’s capsule.

(c) What is meant by selective reabsorption ?

(a) (i) “The length of the small intestine in various animals depends on the food they eat.” Justify the statement.

(ii) Discuss the role of the pancreas and bile juice in the digestion of food in human beings.

(iii) How is the small intestine designed to absorb digested food ?

OR

(b) (i) State the role of rings of cartilage present in the throat.

(ii) Discuss the role of the ribs and diaphragm when air is taken in during the breathing cycle.

(iii) Why do we get muscle cramps during heavy exercise ? Explain.

(a) Design an experiment to demonstrate that carbon dioxide is essential for photosynthesis. Write the observation and conclusion of the experiment.

OR

(b) (i)

In the experimental set-up shown above in diagram (I) atmospheric air is being passed into lime water with a syringe while in diagram (II) air is being exhaled into lime water. The time taken for the lime water to turn milky in both the test tubes is different. Give reason.

(ii) Draw the diagram of an open stomatal pore and label (I) Guard cells, and (II) Chloroplast on it. Mention two functions performed by stomata.

(a) (i) Study the diagram below of alimentary canal of man and name the parts marked as A, B and C. Write the name of the enzyme present in each labelled part.

(ii) Explain how digested food reaches each and every cell of the body and is utilised.

OR

(b) (i) Study the diagram below showing schematic representation of transport and exchange of gases in human heart and name the parts labelled as A, B and C. Mention the function of each part.

(ii) Explain how separation of right and left side of the heart is useful for birds.

Attempt either option A or B

A. Observe the structure of hearts A, B and C shown above and answer the following questions

I. Which of the hearts depicted above is present in both birds and Mammals and how are they able to maintain their body temperature? Give reason for your answer.

II. Which of the hearts depicted above is present in fishes, how does circulation of blood take place in them?

OR

B.

I. Observe both the diagrams A and B. Which diagram indicates inhalation? Describe how it occurs.

II. If diffusion were to move oxygen in our body, it is estimated that it would take 3 years for a molecule of oxygen to get to our toes from our lungs. Then, how is oxygen delivered to all parts of our body?

Human brain has various parts or regions that help in different actions responses and coordination. From the following, identify the part responsible for precision of voluntary actions :

1. Cerebrum
2. Cerebellum
3. Medulla
4. Pons

Directions: Questions 8 and 9 are Assertion and Reason based questions. Two statements are given, one labelled as Assertion (A) and the other as Reason (R). Select the correct answer from the codes (A), (B), (C) and (D) as given below.

Assertion (A) : Reflex actions do not involve thinking.

Reason (R) : Most reflex actions are controlled by the spinal cord.

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 type of tropic movement that is responsible for the movement of the pollen tube towards an ovule from the following options.

1. Hydrotropism
2. Geotropism
3. Chemotropism
4. Phototropism

Walking in a straight line and riding a bicycle are activities which are possible due to coordination of which part of the brain ?

In a synapse, the chemical signal is transmitted from :

1. Dendritic end of one neuron to axonal end of another neuron.
2. Axon to cell body of the same neuron.
3. Cell body to axonal end of the same neuron.
4. Axonal end of one neuron to dendritic end of another neuron.

The growth of tendrils in grapes plants is due to :

1. Effect of light
2. Effect of gravity
3. Rapid cell division in tendril cells in contact with the support
4. Rapid cell division in tendril cells that are away from the support

Following are the statements about the different parts of the brain. Select the correct statements.

(i) The thinking part of the brain is the forebrain.

(ii) Centres for smell, hearing, memory, sight are located in forebrain.

(iii) Salivation, vomiting, blood pressure are controlled by medulla in the hind brain.

(iv) Cerebellum does not control the posture and balance of the body.

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

Identify the endocrine gland that regulates the growth of human body.

1. Pituitary gland
2. Thyroid gland
3. Pancreas
4. Adrenal gland

The growth of tendril in pea plant is due to which of the following ?

1. Effect of chemotropism
2. Effect of gravity
3. Rapid growth of part of the tendril away from the point of contact with the support (object)
4. Rapid growth of the part of the tendril in contact with the support (object)

Identify the hormone that regulates carbohydrate, protein and fat metabolism in the body :

1. Growth hormone
2. Adrenaline
3. Thyroxin
4. Testosterone

Identify the gland that enables the human beings to deal with an emergency situation.

1. Pineal gland
2. Pituitary gland
3. Adrenal gland
4. Pancreatic gland

A man underwent MRI of brain which shows some defects in the cerebellum of his brain. Which activity of that person will be affected ?

1. Heart beat
2. Feeling of hunger and thirst
3. Reflexes
4. Walking in straight line

The plant hormone whose concentration stimulates the cells to grow longer on the side of the shoot which is away from light is :

1. Cytokinins
2. Gibberellins
3. Adrenaline
4. Auxins

Observe the given figures A and B. When chhui-mui (sensitive) plant is touched, its leaves fold. This is due to :

1. Hormonal effect
2. Thermal effect
3. Change in amount of water in cells
4. Electromagnetic effect

The part of the brain which maintains the posture and balance of the body is :

1. Pons
2. Cerebrum
3. Cerebellum
4. Medulla

The plant hormone present in greater concentration in the areas of rapidly dividing cells is :

1. Auxin
2. Cytokinins
3. Gibberellins
4. Abscisic acid

Assertion (A) : In our actions of writing or talking, our nervous system communicates with the muscles.

Reason (R) : Cranial nerves and spinal nerves form the peripheral nervous system.

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.

Which among the following is not a neural action controlled by the part of human brain labelled ‘X’ in the figure above ?

1. Salivation
2. Hunger
3. Vomiting
4. Blood Pressure

The plant hormones promoting rapid cell division in seeds and wilting of leaves respectively are

1. Auxins and Abscisic acid
2. Cytokinins and Abscisic acid
3. Gibberellins and Auxins
4. Abscisic acid and Gibberellins

A pair of endocrine glands located in the human brain is

1. Parathyroid and Pituitary
2. Pineal and Thymus
3. Hypothalamus and Thymus
4. Hypothalamus and Pineal

The part of the hindbrain present immediately above the medulla is :

1. Cerebellum
2. Pons
3. Cerebrum
4. Spinal cord

Application of Abscisic acid on plants promotes :

1. Development of fruits
2. Wilting of leaves
3. Elongation of stem
4. Formation of flowers

In a nerve cell, the site where the electrical impulse is converted into a chemical signal is known as :

1. Axon
2. Dendrites
3. Neuromuscular junction
4. Cell body

Select out of the following a gland which does NOT occur as a pair in the human body :

1. Pituitary
2. Ovary
3. Testis
4. Adrenal

Select from the following a plant hormone which promotes cell division.

1. Gibberellins
2. Auxins
3. Abscissic Acid
4. Cytokinins

A plant growth inhibitor hormone which causes wilting of leaves is called :

1. Auxin
2. Cytokinin
3. Abscisic acid
4. Gibberellin

The correct sequence of events when someone's hand touches a hot object unconsciously :

1. Receptors in skin → Motor neuron → Relay neuron → Sensory neuron → Effector muscle in arm
2. Receptors in skin → Relay neuron → Sensory neuron → Motor neuron → Effector muscle in arm
3. Receptors in skin → Sensory neuron → Relay neuron → Motor neuron → Effector muscle in arm
4. Receptors in skin → Sensory neuron → Effector muscle in arm → Motor neuron → Relay neuron

Sense organ in which olfactory receptors are present is :

1. Nose
2. Skin
3. Tongue
4. Inner ear

A doctor advised a person to take an injection of insulin because :

1. his heart was beating slowly.
2. his blood pressure was low.
3. he was looking short in height.
4. his pancreas was not secreting the required hormone in proper amounts.

The movement of sunflowers is in response to a stimulus such as :

1. gravity
2. chemicals
3. day or night
4. water

Assertion (A) : Chemical co-ordination is seen in both plants and animals.

Reason (R) : Plant hormones control directional growth, whereas in animals, growth is never seen in one direction only.

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.

Select from the following the correct statement about tropic movement in plants :

1. It is due to stimulus of touch and temperature.
2. It does not depend upon the direction of stimulus received.
3. It is observed only in roots and not in stems.
4. It is a growth related movement.

In plants the role of cytokinin is :

1. Promote cell division.
2. Wilting of leaves.
3. Promote the opening of stomatal pore.
4. Help in the growth of stem.

The part in which gustatory receptors are present in our body is :

1. inner ear
2. skin
3. tongue
4. inner lining of nose

Walking in a straight line and riding a bicycle are the activities which are possible due to a part of the brain. Choose the correct location and name of this part from the given table :

Assertion (A) : A hormone called abscisic acid inhibits growth in plants.

Reason (R) : The role of auxins is opposite to that of abscisic acid in plants.

Select the correct answer from the codes (a), (b), (c) and (d) given below.

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 a correct combination of function and part of the brain?

1. Posture and balance: Cerebrum
2. Salivation: Medulla in midbrain
3. Hunger: Pons in hindbrain
4. Blood pressure: Medulla in hindbrain

The blood glucose level in a patient was very high. It may be due to inadequate secretion of:

1. growth hormone from pituitary gland
2. oestrogen from ovary
3. insulin from pituitary gland
4. insulin from pancreas

(a) State two differences between the act of chewing food and salivation on sight of food.

OR

(b) State two differences between pollination and fertilization.

(a) “The timing and the amount of hormone secreted by a gland are regulated in the human body.” Justify this statement with the help of an example.

OR

(b) Electrical impulse is an excellent means to transmit information in the animal body, but there are some limitations to the use of electrical impulses. State any two limitations.

(A) Varun is diabetic. His latest ultrasound reports showed a blockage in his pancreatic duct. How will this affect the dual functioning of the pancreas ?

OR

(B) Sunil unconsciously touched the hot iron rod and immediately withdrew his hand. Which type of action is involved ? Also define this action. Draw a flow chart to show the path followed for this action.

(A) Observe the given figure and identify the labelled parts P, Q, R and S :

OR

(B) Which of the plant hormones are responsible for the following processes ?

(i) Promote cell division

(ii) Inhibition of growth

(iii) Detection of light

(iv) Wilting of leaves

The sensitive plant shows movement of leaves in response to touch. Explain such movement briefly.

Name the parts of hind-brain of the human brain. Which part of the hind-brain controls involuntary actions such as blood pressure and salivation ?

(a) How is brain protected in our body ?

(b) A doctor finds in one of his patients that he is not maintaining a proper posture and balance of his body. State the region of brain and also the part of brain which is responsible for it.

(a) Explain how tendrils help a pea plant climb up other plants or fences.

OR

(b) List two major limitations of the use of electrical impulses as a means of communication between the cells in most multicellular animals.

(A) How is the movement of leaves of a sensitive plant different from the downward movement of the roots ?

OR

(B) There is a hormone which regulates carbohydrate, protein and fat metabolism in our body. Name the hormone and the gland which secretes it. Why is it important for us to have iodised salt in our diet ?

Where are auxins synthesized ? How do they promote phototropism ?

(a) In the diagram given below, name the labelled parts X and Y. Mention one function for each.

OR

(b) Name the parts of the nervous system which are involved in the following activities :

(i) Maintaining body posture

(ii) Salivation

(iii) Hunger

(iv) Answering a question

(a) Write the role of insulin in regulating blood sugar levels in human body. Mention the disease caused due to it.

(b) How is the timing and the amount of release of insulin in the blood regulated ?

(A) Name the part of brain which is responsible for the following actions :

(i) Maintaining posture and balance

(ii) Beating of heart

(iii) Thinking

(iv) Blood pressure

OR

(B) Where are auxins synthesized in a plant ? Which organ of the plant shows :

(i) Positive phototropism

(ii) Negative geotropism

(iii) Positive hydrotropism

Write the name and function of parts (i) and (ii) in the diagram of a neuron given below.

(a) List two differences between the movement of leaves of a sensitive plant and the movement of a shoot towards light.

OR

(b) What happens at synapse between two neurons ? State briefly.

Students to attempt either option A or B.

A. Which parts of the brain perform certain actions for which we do not have any thinking control? What are such actions called, give two examples.

OR

B. How is the information of touch in the 'sensitive plant' controlled and coordinated?

Give reasons for the following :

(a) Adrenal gland is known as the stress gland of the body.

(b) Prenatal sex determination is banned in India.

(c) Vegetative propagation is advantageous in some plants.

Plants have neither a nervous system nor muscles, even then they respond to stimuli. For example, the leaves of chhui-mui (touch-me-not) plant when touched begin to fold up and droop.

(a) How is the information communicated in “touch-me-not” plants ?

(b) What enables the plant cells to bring out the observable response ?

(c) Differentiate the movement mentioned above from the movement of tendrils in a pea plant.

(a) Define hormone.

(b) “Hormones should be secreted in precise quantities. We have a feedback mechanism through which this is done.” With the help of an example justify the statement.

State two limitations of electrical impulses in multicellular organisms. Why is chemical communication better than electrical impulses as a means of communication between cells in multicellular organisms?

Define reflex action. With the help of a flow chart show the path of a reflex action such as sneezing.

(a) List two constituents of Central Nervous System (CNS). How are these components protected from injuries ?

(b) Write two limitations of the use of electrical impulses.

Taking the example of any two animal hormones along with their gland of secretion, explain how these hormones help (i) in growth and development and (ii) regulate metabolism, in the body.

Name the hormone released and the gland which secretes it in human beings during scary situations. How does the body respond to enable it to deal with the situation ?

(a) Name the gland and the hormone secreted by it in scary situations in human beings. List any two responses shown by our body when this hormone is secreted into the blood.

OR

(b) In the given diagram

(i) Name the parts labelled A, B, and C.

(ii) Write the functions of A and C.

(iii) Reflex arcs have evolved in animals ? Why ?

Draw and explain how the nerve cells help in transmission of impulses?

How do muscles move at the cellular level and respond when processed messages are received from the brain?

Read the following passage and answer the questions that follow :

A middle-aged person is facing some cognitive changes in himself. His early symptoms included mild forgetfulness. For example, forgetting where he left his mobile or failing to find words to complete his sentences. He was facing problems in driving a car, climbing up and down the stairs, inserting a plug into an outlet. He slowly developed a sad mood and anxiety.

(a) What are voluntary actions ? [1]

(b) Which part of the brain is responsible for precision of voluntary actions ? [1]

(c) (i) Explain the role of the medulla. [2]

OR

(c) (ii) How do the animal muscles move ? [2]

Plants exhibit movements in response to various environmental stimuli to adopt and survive in their surroundings. These movements, influenced by external factors such as light, gravity, water and chemicals are regulated by specific plant hormones. For example, the differential growth of plant parts allows them to bend, grow or orient themselves in particular directions. Roots and shoots often show contrasting response to the same stimulus, highlighting the complex mechanisms involved in plant growth and development.

(a) Why is hydrotropism essential for plants ?

(b) What role does auxin play in the growth of plants ?

(c) Differentiate between movement shown by the sensitive plant and tropic movement by plants (Two points).

OR

(c) How does movement of roots differ from that of shoots in response to gravity and light ?

A person while climbing up a rocky hill comes into a panic state and fear. His body starts reacting in a “flight-or-flight” condition to adjust to the dangerous and stressful situation. Based on the above facts, answer the questions that follow.

(a) (i) Name the hormone secreted in the blood of the person in this situation. [2]

OR

(a) (ii) Name the source gland of the hormone secreted in this condition. [2]

(b) State any two responses in the body of the person as a result of the secretion of this hormone. [1]

(c) How does the action of the chemical signal in terms of hormones differ from the electrical impulses via nerve cells ? [1]

In life there are certain changes in the environment called ‘stimuli’ to which we respond appropriately. Touching a flame suddenly is a dangerous situation for us. One way is to think consciously about the possibility of burning and then moving the hand. But our body has been designed in such a way that we save ourself from such situations immediately.

(i) Name the action by which we protect ourself in the situation mentioned above and define it.

(ii) Write the role of (a) motor and (b) relay neuron.

(iii) (A) What are the two types of nervous system in human body? Name the components of each of them.

OR

(iii) (B) Which part of the human brain is responsible for :

(a) thinking

(b) picking up a pencil

(c) controlling blood pressure

(d) controlling hunger

The growth movements of plant parts in which the direction of the stimulus determines the direction of the response is known as tropic movements or tropism. Plants also have non-directional movements which may not be growth dependent.

(I) Name the movement which causes ‘X’ and ‘Y’ to grow downwards and upwards respectively. (Refer above figure)

(II) Write the name of a hormone that plays a major role in (i) falling of leaves (ii) rapid cell division

(III) (a) Leaves of the sensitive plant move very quickly in response to ‘touch’. How is this stimulus of touch communicated and explain how the movement takes place.

OR

(III) (b) Name the plant hormone which is synthesized at the shoot tip. How does this hormone helps the plant to bend towards light ?

In animals the control and coordination is provided by nervous and muscular tissues. Nervous tissue is made of an organized network of nerve cells or neurons. In human beings, thinking is a complex activity which involves more complex mechanisms and neural connections. These are concentrated in the brain which is the main coordinating centre of the human body. The brain and spinal cord constitute the Central Nervous System which receives information from all parts of the body and integrates it.

(a) How is the brain protected from shocks and injuries ?

(b) Write the main functions of (i) sensory neuron and (ii) motor neuron in a reflex arc.

(c) Which part of the brain is involved in activities like (i) picking a pencil and (ii) vomiting ? State whether these actions are voluntary or involuntary.

OR

(c) How does the central nervous system communicate with other parts of the body to carry out various activities ? Name two components of this system.

Attempt either (a) or (b) :

(a) (i) What are the limitations of electrical impulses in multicellular organisms ?

(ii) (I) In a 'Touch-me-not' plant, movement is seen on touch. Compare it with that of animals.

(II) Name the type of movement shown by the growth of pollen tube towards an ovule.

OR

(b) (i) Reflex arcs have evolved in animals because the thinking process of the brain is not fast enough for all situations. Draw a flow chart showing the path of a reflex arc.

(ii) Given below are some actions/activities. Identify the part of brain involved in controlling them :

(I) Taking a walk in the garden
(II) Dancing
(III) Blood pressure

(A) (a) Analyse the given situations and interpret the possible reason for each :

(i) Iodine deficiency in diet increases the possibility of a disease of swollen neck in a person.

(ii) Some people in population may have very short heights (dwarfs).

(iii) Thick facial hairs develop in boys at the age of 10-12 years.

(b) Explain two reasons which necessitate the need of chemical communication in multicellular organisms.

OR

(B) (a) Differentiate between voluntary and involuntary action.

(b) Define reflex action. With the help of a flow diagram, show the correct sequence of path of Nerve impulse from place of its origin.

(a) (i) Distinguish between hormonal co-ordination in plants and animals.

(ii) Which part of the brain is responsible for -

(1) intelligence

(2) riding a bicycle

(3) vomiting

(4) controlling hunger

(iii) How is brain and spinal-cord protected against mechanical injuries ?

OR

(b) (i) What are tropic movements ? Give an example of a plant hormone which (1) inhibits growth and (2) promotes cell division.

(ii) Explain directional movement of a tendril in pea plant in response to touch. Name the hormone responsible for this movement.

(a) (i) Define a reflex arc. Why have reflex arcs evolved in animals ? Trace the sequence of events which occur, when you suddenly touch a hot object.

(ii) Name the part of nervous system which helps in communication between the central nervous system and other parts of the body. What are the two components of this system ?

OR

(b) (i) Leaves of chhui-mui plant begin to fold up and droop in response to a stimulus. Name the stimulus and write the cause for such a rapid movement. Is there any growth involved in the movement ?

(ii) Define geotropism in plants. What is meant by positive and negative geotropism ? Give one example of each type.

(a) (i) List three points of difference between nervous and hormonal mechanisms for control and coordination in animals.

(ii) How are auxins related with the bending of plant shoot towards unidirectional light ? Explain.

OR

(b) (i) Name the disorder which a person is likely to suffer from due to the following :

(I) Over-secretion of growth hormone

(II) Deficiency of oestrogen in females

(III) Less secretion of thyroxine

Also name the gland that secretes each of the hormones mentioned above.

(ii) How is the timing and amount of hormone released regulated ? Explain with the help of an example.

Identify the type of reproduction shown in the diagram given below :

1. Budding
2. Fragmentation
3. Spore Formation
4. Binary Fission

Identify the correct statement for spirogyra, leishmania and hydra :

1. they reproduce sexually.
2. they are unicellular.
3. they are multicellular.
4. they reproduce asexually.

Spirogyra, despite being a multi-cellular organism, still shows a simple reproductive method. Select the correct option with regard to reproduction in Spirogyra :

1. Asexual reproduction by division of cells into two cells
2. Sexual reproduction by division of cells into many cells
3. Asexual reproduction by breaking up of Spirogyra filaments into smaller parts
4. Sexual reproduction by the formation of gametes after meiosis of cells of filaments followed by fusion of male and female gametes

If the part ‘P’ of the flower is removed, which of the following processes will not take place ?

1. Formation of pollens
2. Formation of flower
3. Formation of fruit
4. Formation of seed

Assertion (A) : Variations are not often seen in off-springs produced by asexual reproduction.

Reason (R) : DNA molecule generated by replication is not similar to the original DNA.

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.

In human beings, the implantation of fertilised egg takes place in which part of female reproductive system ?

1. Oviduct
2. Cervix
3. Uterus
4. Vagina

Assertion (A) : Bacteria that can withstand heat have better chances of survival in a heat wave.

Reason (R) : Accumulation of variations in a species increases the chances of its survival in changing environment.

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.

From the following, identify the sexually transmitted diseases caused by bacteria.

(i) Warts   (ii) Gonorrhoea   (iii) AIDS   (iv) Syphilis

Choose the correct option :

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

Directions: Questions 8 and 9 consist of two statements - Assertion (A) and Reason (R). Answer these questions selecting the appropriate option from (A), (B), (C) and (D) given below.

Assertion (A) : In regeneration, organisms have the ability to give rise to new individual organisms from their body parts.

Reason (R) : Simple animals like Hydra and Planaria show regeneration.

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 correct/true statement(s) for a bisexual flower is/are :

(i) They possess both stamen and pistil.

(ii) They possess either stamen or pistil.

(iii) They exhibit either self-pollination or cross-pollination.

(iv) They cannot produce fruits on their own.

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

Bryophyllum produces new plant through :

1. Apical buds formed on the tip of the plant
2. Vegetative buds produced in the notches of the leaf
3. Flowers produced in the notches of the branches
4. Fruits formed on the branches of the plant

The number of chromosomes in a cell division is halved. This kind of cell division is observed in :

1. Only testis
2. Only ovary
3. Ovary and testis both
4. All cells of the body

Match Column-I with Column-II and select the correct option from the choices provided.

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

Select a pair of bisexual flowers from the following :

1. Papaya and mustard
2. Hibiscus and mustard
3. Hibiscus and papaya
4. Hibiscus and watermelon

Plants like rose and banana have lost the capacity to produce :

1. flowers
2. buds
3. seeds
4. fruits

In a bisexual flower the male gametes are present in the :

1. anther
2. ovary
3. stigma
4. filament

The modes of reproduction in Spirogyra and Planaria respectively are

1. Regeneration and budding
2. Regeneration and fragmentation
3. Fragmentation and regeneration
4. Budding and regeneration

Assertion (A) : The embryo gets nutrition from the mother's blood with the help of a special tissue called placenta.

Reason (R) : Placenta is a disc which is embedded in the uterine wall.

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, and 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.

Select the option having correct matching of the organism given in Column I with the mode of reproduction in Column II :

1. P-4, Q-2, R-1, S-3
2. P-3, Q-4, R-5, S-2
3. P-3, Q-4, R-1, S-2
4. P-4, Q-3, R-2, S-1

The end product of meiosis in a reproductive cell in plants is :

1. Zygote
2. Pollen grains
3. Sperms
4. Egg

In which of the following organisms, multiple fission is a means of asexual reproduction ?

1. Yeast
2. Leishmania
3. Paramoecium
4. Plasmodium

Identify the mode of asexual reproduction in the following organism :

1. Fragmentation
2. Multiple fission
3. Budding
4. Binary fission

Part(s) of a flower which attracts insects for pollination is (are)

1. petals and Sepals
2. anther and Stigma
3. petals only
4. sepals only

Assertion (A) : Offsprings produced by asexual reproduction are genetically similar to the parents.

Reason (R) : Asexual reproduction involves a single parent.

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 correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.

The plants that can be raised by the method of vegetative propagation are :

1. Sugarcane, roses, grapes
2. Sugarcane, mustard, potato
3. Banana, orange, mustard
4. Papaya, mustard, potato

The part of seed which is a source of food during germination of seed is :

1. Cotyledon
2. Radicle
3. Plumule
4. Embryo

The incorrect statement about placenta is :

1. It is a disc embedded in the uterine wall.
2. It contains villi on the embryo's side of the tissue.
3. It has a very small surface area for glucose and oxygen to pass from mother to the embryo.
4. The embryo gets nutrition from the mother's blood through it.

Select from the following the conditions responsible for the rapid spread of bread mould on a slice of bread :

(i) Formation of large number of spores

(ii) Presence of moisture and nutrients in bread

(iii) Low temperature

(iv) Presence of hyphae

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

In bread mould, the structures labelled A and B respectively are :

1. hyphae and spore
2. root and sporangium
3. hyphae and sporangium
4. root and spores

Select the INCORRECT match (between the plant and its vegetative part) from the following :

1. Bryophyllum, leaf
2. Potato, stem
3. Money-plant, stem
4. Rose, root

Plants which bear unisexual flowers are :

1. Mustard and Papaya
2. Hibiscus and Watermelon
3. Mustard and Hibiscus
4. Watermelon and Papaya

Assertion (A) : When a bacterium divides into two, and the resultant two bacteria divide again, the four bacteria produced would be almost similar.

Reason (R) : DNA copying involves small inaccuracies in the reproduction process.

Select the correct answer from the codes (a), (b), (c) and (d) given below.

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 number of chromosomes in parents and offsprings of a particular species undergoing sexual reproduction remain constant due to :

1. doubling of chromosomes after zygote formation.
2. halving of chromosomes after zygote formation.
3. doubling of chromosomes before gamete formation.
4. halving of chromosomes at the time of gamete formation.

The bacterial and the viral infections that may be caused due to unsafe sex respectively are :

1. Warts and HIV-AIDS
2. HIV-AIDS and Warts
3. Gonorrhoea and Syphilis
4. Syphilis and Warts

Choose the correct order of the stages of binary fission in Leishmania.

1. I, II, III, IV, V
2. I, III, II, V, IV
3. I, III, V, II, IV
4. I, II, III, V, IV

Consider the following three flowers namely X, Y and Z. Which flower(s) would develop into a fruit ?

1. ‘X’ only
2. ‘Z’ only
3. ‘X’ and ‘Y’ only
4. ‘Y’ and ‘Z’

The organism in which an outgrowth on the parent body develops into a new individual is :

1. Amoeba
2. Paramecium
3. Rhizopus
4. Yeast

In a controlled experiment, the anthers of a mustard plant's flowers were carefully removed in the bud stage before they matured. The bud was covered with a paper bag.

What will be the most likely result for these flowers?

1. They will still produce seeds and fruit through self-pollination.
2. They will attract more insects and produce larger flowers but no fruit.
3. They will not produce any seeds or fruits.
4. They will produce seeds and fruits that are genetically identical to the parent.

The Vas deferens and the Oviduct are both targets for surgical contraception (Vasectomy and Tubectomy respectively). Analysing the process of reproduction, what common biological event is prevented by blocking both these structures?

1. The production of gametes (sperm and egg).
2. The implantation of the fertilized egg into the uterine wall.
3. The successful meeting and fusion of the male and the female gametes.
4. The release of hormones - testosterone and estrogen.

Draw a neat diagram to show germination of pollen on the female reproductive part of the flower. Name and label only the following parts :

(a) The part that receives the pollen grain.

(b) The structure that carries the male germ cell to reach the female germ cell.

“Variation is useful for the survival of species over time.” Explain this statement with the help of an example.

(a) In a tobacco plant, the male gametes have twenty-four chromosomes. The number of chromosomes in the female gametes is also twenty-four. What is the number of chromosomes in the zygote produced ? How is the chromosome number in the zygote re-established ?

OR

(b) Draw a diagram of the longitudinal section of a flower and label : Sepal, Petal, Ovary and Stigma.

Following are the diagrammatic representations of different organisms performing a process.

(i) Identify the organisms (a) and (b).

(ii) Name the process commonly shown in both the figures.

(iii) How is this process advantageous to the organisms ?

Draw labelled diagrams to show different stages of budding in Hydra.

(a) Write one function each of the following, in a seed :

(i) Seed coat

(ii) Cotyledon

(iii) Radicle

(iv) Plumule

OR

(b) Write the main steps to culture yeast in the laboratory.

Give reasons :

(a) The male reproductive organ responsible for formation of germ cells is located outside the abdominal cavity.

(b) The roles of the glands, present along the path of the vas-deferens, are very significant.

"Stability of DNA in a species is ensured during sexual reproduction." Justify the statement.

The survival of a species is promoted through creation of variations. Illustrate with an example.

Some unicellular organisms such as Plasmodium and Leishmania differ in the manner in which they reproduce. Name and explain the reproductive process taking place in them.

List two ways due to which variations arise in a population. State the importance of variation.

Name the glands which add their secretions to the sperms. List two function of these secretions.

(a) Which of the following flowers will have higher possibility of self-pollination ?

Mustard, Papaya, Watermelon, Hibiscus

(b) List the two reproductive parts of a bisexual flower.

Which one of the two multicellular organisms Spirogyra and Planaria reproduces by regeneration and why ? Give an example of any other organism which can also reproduce by the same process.

Give reasons :

(i) Placenta is extremely essential for foetal development.

(ii) Uterine lining becomes thick and spongy after fertilisation.

(a) Name the reproductive and non-reproductive parts of bread mould (Rhizopus).

(b) List any two advantages of vegetative propagation.

Name the reproductive parts of an angiosperm. Where are these parts located ? Explain the structure of its male reproductive part.

OR

What is puberty ? Mention any two changes that are common to both boys and girls in early teenage years.

Suggest any two contraceptive methods to control the size of human population and explain them.

Name the part/organ of the human female reproductive system

(a) where contraceptive devices such as loop or copper-T are placed to prevent pregnancy.

(b) which is blocked to prevent the transfer of eggs.

(c) where formation of green cells as ova takes place.

(d) from where the embryo gets nutrition from the mother's blood.

Mention the functions of (a) Placenta (b) Fallopian tubes (c) Uterus and (d) Ovary in the human female reproductive system.

(a) Differentiate between binary fission in Amoeba and binary fission in Leishmania.

(b) How does reproduction take place in malarial parasite ?

How is the number of chromosomes in the progeny of sexually reproducing organisms re-established ? Explain.

Name the parts A, B and C of the diagram given below. Write a function of the part B.

What changes are observed in the uterus subsequent to implantation of the young embryo in a human female?

(a) Define fertilisation.

(b) What happens to Zygote, Ovule, Ovary and Stamens after fertilisation in a flowering plant ?

Explain the events that take place once a sperm reaches the oviduct till it becomes a foetus. Write the role of placenta in pregnancy.

(a) Explain with the help of a labelled diagram, the process of reproduction in Hydra by budding. Name the cells used for reproduction in this process.

OR

(b) List two roles of each of the following in human reproductive system :

(i) Seminal vesicles and prostate gland

(ii) Oviduct

(iii) Testis

(a) Name a part of the flower which (i) persists even after a fruit is formed, (ii) attracts insects for pollination, (iii) produces pollen grains and (iv) changes into seed after fertilisation.

(b) After pollination, how does a male germ cell reach the ovary ? Mention the significance of this event.

(a) Name the parts of a bisexual flower that are not directly involved in reproduction.

(b) Differentiate between self pollination and cross pollination. List any two significance of pollination.

(c) What is the fate of ovules and ovary after fertilization in a flower ?

(a) Mention one function each of the following organs in human male reproductive system :

(i) Testis

(ii) Scrotum

(iii) Vas deferens

(iv) Prostate gland

(b) Name the type of germ cell which (i) is motile, and (ii) stores food.

In flowering plants, the pollen grains are transferred to stigma by pollination but the female germ cells are present in the ovary. Explain with the help of a labelled diagram (only concerned parts), how the male germ cell reaches the ovary.

What is vegetative propagation ? Name two methods in which this process is used to grow many plants. List any two advantages of vegetative propagation.

When a girl is born, the ovaries already contain thousands of immature eggs. On reaching puberty, some of these start maturing. One matured egg is released every month by one of the ovaries. The two oviducts unite into an elastic bag-like structure known as uterus.

(a) Write the site of fertilization in human female. [1]

(b) How does the uterus prepare itself to receive and nurture the growing embryo ? Explain. [1]

(c) (i) What happens when the egg is not fertilized ? [2]

OR

(c) (ii) How does the developing embryo get nutrition from the mother’s blood ? Explain. [2]

Asexual reproduction involves a single parent to produce offsprings without the formation of gametes. It occurs by the following ways : Fission, Budding, Fragmentation, Spore formation and Regeneration. In one of the methods like regeneration, Planaria A is cut horizontally into three pieces – L, M and N and Planaria B is cut vertically into two equal halves – O and P.

(a) Which of the cut pieces of the two Planaria could regenerate to form a complete organism ?

(b) Give an example of another organism which follows the same mode of reproduction as Planaria.

(c) What is the meaning of 'development' in regeneration ?

OR

(c) Differentiate between regeneration and fragmentation.

Pollination is an important process in sexual reproduction of plants. It is an essential process that facilitates fertilisation in plants. Pollinating agents can be wind, water, insects and birds. Several changes take place in the flower after the fertilization has taken place.

(a) Write the main difference between self-pollination and cross-pollination.

(b) Name the part of the flower which attracts insects for pollination. What happens to this part after fertilisation ?

(c) (i) Define fertilisation. What is the fate of ovules and the ovary in a flower after fertilisation ?

OR

(c) (ii) In a germinating seed, which parts are known as future shoot and future root ? Mention the function of cotyledon.

Plantation drives are often carried out especially during monsoon season for the protection of our environment. Such programmes need a lot of saplings for tree plantation. Plants are propagated by sexual or asexual means in fields and nurseries. Over the years horticulturists have developed asexual methods that use vegetative parts of the plants to multiply. Many plants can reproduce by this method naturally as well as by artificial means.

(a) Which specific part of the plant is used for sexual and asexual means of propagation to produce a new plant ? [1]

(b) Give one example of (i) a flower, and (ii) a fruit grown by vegetative propagation. [1]

(c) (i) List two advantages of growing plants by vegetative propagation. [2]

OR

(c) (ii) Describe an activity to show how potatoes reproduce asexually. [2]

All the reproductive methods of living organisms are broadly categorized into two types : 1. Asexual reproduction, and 2. Sexual reproduction.

Asexual reproduction involves the participation of a single parent without the formation of gametes, fertilisation and transfer of genetic material. This method is a common means of rapidly increasing offsprings under favourable conditions.

(a) Name the type of fission that occurs in Leishmania and Plasmodium.

(b) Write one advantage of sexual mode of reproduction over asexual reproduction.

(c) Give reasons why :

(i) Colonies of yeast fail to multiply in water but multiply in sugar solution.

(ii) Rhizopus individuals do not grow on a dry slice of bread.

OR

(c) Name the filamentous structures a student could identify when he collected water from a pond that appeared dark green. How do these organisms multiply ? Explain.

The modes by which various organisms reproduce depend on the body design of the organisms. In asexual reproduction, a single individual parent produces offsprings without the involvement of gametes. This method is a common means of increasing the offsprings rapidly under favourable conditions. Asexual reproduction occurs mostly in unicellular organisms, some plants and certain simple multicellular animals.

(a) State the name of the organism in which binary fission takes place in a definite orientation. Also name the disease caused by this organism.

(b) List any two advantages of producing plants through vegetative propagation.

(c) (i) Explain the process of budding in Hydra.

OR

(ii) What happens when (I) a spirogyra filament matures and attains a considerable length, and (II) a sporangia in Rhizopus bursts on maturation ?

(a) Given below are certain situations. Analyse each and describe its possible impact :

(i) A population of bacteria living in temperate waters whose temperature increased by global warming.

(ii) The sperm encounters the egg when it reaches the oviduct in human females.

(iii) Self pollination does not occur in a flower that contains only pistil.

(iv) Egg does not get fertilised in a human female.

(v) When the seed is placed under appropriate condition of water and air in the soil ?

OR

(b) Given below are certain situations. Analyse and describe what would happen when :

(i) Spores are liberated from blob-like structures of the bread mould ?

(ii) Leaves of bryophyllum fall on wet soil ?

(iii) A pollen from different species land on the stigma of totally unrelated species ?

(iv) Copper-T is placed in the uterus of a human female ?

(v) Spirogyra breaks into smaller fragments upon maturation ?

Attempt either (a) or (b) :

(a) (i) Name an organ that helps in the formation of male germ cells in humans and also mention the condition that favours the formation of male germ cells.

(ii) In male reproductive system, write the pathway followed to deliver male germ cells to the site of fertilisation.

(iii) Mention the main physical feature of the male germ cell that helps it move towards the female germ cell. [2+2+1=5]

OR

(b) Radha has three children. She does not want to have more children. Radha visits a nearby hospital, to know the methods to prevent pregnancy.

(i) Mention the name of any two ways other than the surgical methods, following which Radha can avoid unwanted pregnancies.

(ii) Name the surgical methods to prevent pregnancy.

(iii) Give one example each of sexually transmitted diseases caused by bacteria and virus. [2+2+1=5]

Attempt either (a) or (b) :

(a) Observe the given diagram and answer the questions that follow :

(i) Give the name of the structure and type of reproduction shown in the above diagram.

(ii) State one advantage and one disadvantage of the above mentioned method of reproduction.

(iii) Give reason : Asexual reproduction lacks genetic variation.

(iv) Why have higher organisms resorted to sexual reproduction in spite of its complexity ?

OR

(b) Observe the given diagram and answer the questions that follow :

(i) Give the name and type of reproduction shown in the above diagram.

(ii) Comment on the processes taking place in stage P.

(iii) Name an organism which reproduces by the above mentioned method.

(iv) Name the method that can be used to raise plants that have lost their capacity to produce seeds. List any two advantages of growing plants by such a method.

(A) (i) In an angiospermic flower, fertilization is said to take place when male gametes carried in the pollen tube fuse with the female gamete, present in the embryo sac. This results in lot of changes in different parts of the flower. State the changes taking place in the following structures of flower post fertilization :

(a) Zygote

(b) Ovule

(c) Ovary

(d) Sepals

(ii) Define germination.

OR

(B) (i) Sugarcane does not produce seeds so name the process through which it will be able to reproduce.

(ii) List any two advantages of this method.

(iii) Besides sugarcane, give two more examples of plants that reproduce by this method.

(iv) Why regeneration is not possible in all the types of animals ?

(A) In flowering plants, the process of pollination leads to fertilization.

(i) Explain with the help of a well-labelled diagram how the male germ cell from the pollen grain reaches the female germ cell located in the ovule.

(ii) Differentiate between self-pollination and cross-pollination.

(iii) Identify and name the parts 'R' and 'S' in the given diagram of seed.

OR

(B) (i) Name the special tissue inside the uterus that provides nutrition to the developing embryo. Describe its structure. State its two functions besides nutrition. [3]

(ii) Write any two sexually transmitted diseases in humans and their causative microbial agents. [2]

(a) (i) Write the functions of the following parts of human female reproductive system :

(I) Ovary

(II) Fallopian tube

(III) Uterus

(ii) State briefly two contraceptive methods used by human males.

OR

(b) (i) Differentiate between self-pollination and cross-pollination.

(ii) Identify A, B and C in the diagram given below and write one function of each.

(a) (i) Identify the parts ‘X’ and ‘Y’ in the figure given below :

(ii) Name the yellowish coloured structures produced by the part labelled as ‘Y’.

(iii) Write the name of the process by which these are transferred to the part labelled as ‘X’.

(iv) Explain the process of seed formation in a flowering plant.

OR

(b) (i) Name the type of asexual mode of reproduction shown in the given figure.

(ii) Identify the unicellular organism in the diagram.

(iii) List any two advantages of asexual reproduction over sexual reproduction.

(iv) Name and explain any one mode of asexual reproduction observed in Hydra.

(A) (i) What is regeneration? Give one example of an organism that shows this process and one organism that does not. Why does regeneration not occur in the latter?

(ii) Water in a pond appears dark green and contains filamentous structures. Name these structures and the method by which they reproduce. Explain the process.

OR

(B) (i) Name the part performing following functions in human male reproductive system :

(a) Carries sperm

(b) Production of male gametes

(c) Whose secretion makes the transport of sperms easier

(d) Provide suitable temperature for sperm formation

(ii) Write any two characteristics of sperms.

(iii) What are surgical contraceptive methods? Give the side effect caused by this procedure.

(a) Define Puberty. List any two changes seen in boys at the time of puberty.

(b) Why are testes in human males located outside the abdominal cavity in scrotum ?

(c) List any three techniques of contraception used by humans. Which one of these is not meant for males ?

OR

(a) Name the part performing following functions in human female reproductive system :

(i) production of eggs

(ii) site of fertilization

(iii) site of implantation

(iv) entry of the sperms

(b) What changes are observed in the uterus :

(i) subsequent to implantation of zygote and

(ii) if an egg does not get fertilized ?

(a) (i) In which form is the information for inheritance of features transmitted from one generation to the next generation ?

(ii) Differentiate between binary fission in Amoeba and Leishmania.

(iii) "Fragmentation cannot be a method of reproduction in all multicellular organisms." Justify this statement.

OR

(b) (i) Define placenta. State the structure and role of placenta in the development of embryo in human beings.

(ii) List three categories of contraceptives and give one example of each.

(A) (i) Name three techniques/devices used by human females to avoid pregnancy. Mention the side effects caused by each.

(ii) What will happen if in a human female (a) fertilisation takes place, (b) an egg is not fertilised ?

OR

(B) (i) Draw a diagram showing spore formation in Rhizopus and label the (a) reproductive and (b) non-reproductive parts. Why does Rhizopus not multiply on a dry slice of bread ?

(ii) Name and explain the process of asexual reproduction that takes place in Hydra.

(a) (i) What are spores ? On which structures are they formed ? How do they overcome unfavourable conditions ? Name the organism which multiplies with the help of these structures.

(ii) Give two reasons why some plants are grown by the method of vegetative propagation. List two methods used to grow plants vegetatively.

OR

(b) (i) Study the diagram given below and name the parts marked as A, B and C. What happens when B reaches C in the ovary ? Mention its significance.

(ii) Write the post fertilisation changes that occur in a flower.