25 multiple-choice (MCQ / objective) questions from this chapter, in every exam-style shape used in the paper. Every question comes with an explanation along with the answer, so you remember why the option is correct, not just which one it is.
1 Direct Questions
Direct Questions
- 1 markWhich cell organelle contains chlorophyll and carries out photosynthesis?
(A) Mitochondria(B) Chloroplast(C) Ribosome(D) Nucleus - 1 markWhich enzyme in saliva breaks down starch into simple sugar?
(A) Pepsin(B) Trypsin(C) Salivary amylase(D) Lipase - 1 markThe first common step of respiration, breaking glucose down to pyruvate, takes place in the
(A) Mitochondria(B) Nucleus(C) Cytoplasm(D) Chloroplast - 1 markAerobic respiration, which releases a large amount of energy, takes place in the
(A) Cytoplasm(B) Nucleus(C) Chloroplast(D) Mitochondria - 1 markWhich blood vessels carry blood away from the heart to the organs of the body?
(A) Veins(B) Capillaries(C) Arteries(D) Lymph vessels - 1 markOxygen-rich blood arriving from the lungs first enters which chamber of the heart?
(A) Right atrium(B) Right ventricle(C) Left atrium(D) Left ventricle - 1 markThe basic filtration unit of the kidney is called the
(A) Ureter(B) Bowman’s capsule(C) Nephron(D) Urethra - 1 markThe sticky layer of bacteria and food particles that forms on teeth, blocking saliva from reaching the enamel to neutralise acid, is called
(A) Dental caries(B) Dental plaque(C) Gastric mucus(D) Bile - 1 markSmoking destroys the tiny hair-like structures in the upper respiratory tract that normally sweep out germs, dust and other harmful particles from inhaled air. These structures are called
(A) Villi(B) Cilia(C) Alveoli(D) Nephrons - 1 markIn Paramoecium, food is moved to a fixed spot on the cell by the beating of
(A) Pseudopodia(B) Cilia(C) Guard cells(D) Villi - 1 markDuring breathing in (inhalation), what happens to the ribs and the diaphragm?
(A) Ribs lift and the diaphragm flattens(B) Ribs lower and the diaphragm domes upward(C) Both the ribs and the diaphragm stay still(D) Ribs lift and the diaphragm also domes upward
2 Assertion-Reason
Assertion-Reason
- 1 markAssertion (A): Anaerobic respiration in yeast produces ethanol and carbon dioxide.
Reason (R): Anaerobic respiration takes place in the mitochondria in the absence of oxygen.
(A) A is true, R is true, R is the correct explanation(B) A is true, R is true, R is NOT the correct explanation(C) A is true, R is false(D) A is false, R is true - 1 markAssertion (A): In birds and mammals, the right and left sides of the heart are completely separated, so oxygenated and de-oxygenated blood do not mix.
Reason (R): Birds and mammals have high energy needs, because they constantly use energy to maintain their body temperature, so they need a highly efficient supply of oxygen.
(A) A is true, R is true, R is the correct explanation(B) A is true, R is true, R is NOT the correct explanation(C) A is true, R is false(D) A is false, R is true
3 Match the Following
Match the Following
- 1 markMatch Column A with Column B:
A: 1. Salivary glands 2. Stomach 3. Pancreas 4. Small intestine wall
B: (i) Trypsin and lipase (ii) Intestinal juice (iii) Salivary amylase (iv) Hydrochloric acid and pepsin
(A) 1-iv, 2-iii, 3-ii, 4-i(B) 1-iii, 2-iv, 3-i, 4-ii(C) 1-i, 2-ii, 3-iii, 4-iv(D) 1-ii, 2-i, 3-iv, 4-iii - 1 markMatch Column A with Column B:
A: 1. Artery 2. Vein 3. Capillary 4. Platelet
B: (i) Plugs a leak by clotting blood (ii) One-cell-thick wall for exchange (iii) Carries blood away from the heart (iv) Has valves to prevent backflow
(A) 1-i, 2-ii, 3-iii, 4-iv(B) 1-iv, 2-i, 3-iii, 4-ii(C) 1-iii, 2-iv, 3-ii, 4-i(D) 1-ii, 2-iii, 3-i, 4-iv
4 Statement-Based Questions
Statement-Based Questions
- 1 markStatement I: Herbivores like cows need a longer small intestine than carnivores.
Statement II: Cellulose in a grass-based diet takes longer to digest than meat.
(A) Both true, II is the correct explanation(B) Both true, II is NOT the correct explanation(C) I true, II false(D) I false, II true - 1 markStatement I: During the day, transpiration pull is the major force moving water up the xylem.
Statement II: Stomata are open during the day, so water evaporates fast from leaf cells, creating a suction that pulls water upward.
(A) Both true, II is the correct explanation(B) Both true, II is NOT the correct explanation(C) I true, II false(D) I false, II true
5 Arrange in the Correct Order
Arrange in the Correct Order
- 1 markStarting from blood returning to the heart from the body, arrange the following steps of blood flow through the human heart in the correct order: (i) blood is pumped to the lungs from the right ventricle (ii) blood is pumped to the body from the left ventricle (iii) blood enters the right atrium from the body (iv) oxygenated blood enters the left atrium from the lungs
(A) iii-i-iv-ii(B) i-iii-ii-iv(C) iii-iv-ii-i(D) iv-i-iii-ii - 1 markStarting in the lungs, arrange the following events in the correct order for oxygen used in aerobic respiration in the human body: (i) pyruvate is broken down using the oxygen inside the mitochondria, giving carbon dioxide and water (ii) haemoglobin in the red blood corpuscles takes up oxygen from the alveolar air (iii) the carbon dioxide formed, mostly dissolved in the blood, is brought to the alveoli and released (iv) the oxygen is released to a tissue cell that is deficient in oxygen
(A) i-ii-iii-iv(B) ii-iv-i-iii(C) iv-ii-i-iii(D) ii-i-iv-iii
6 Fill in the Blanks
Fill in the Blanks
- 1 markThe nitrogenous waste removed by the kidneys is urea or ______.
(A) Glucose(B) Uric acid(C) Glycogen(D) Bile - 1 markThe loss of water, as vapour, from the aerial parts of a plant is called ______.
(A) Translocation(B) Transpiration(C) Respiration(D) Osmosis
7 Odd One Out
Odd One Out
- 1 markPick the odd one out, based on whether the animal shows double circulation:
(A) Fish(B) Amphibian(C) Bird(D) Reptile
8 Passage-Based Questions
Passage-Based Questions
Passage
A student took 1 mL of 1% starch solution in each of two test tubes, A and B. 1 mL of saliva was added to test tube A only, and both tubes were left undisturbed for 25 minutes. A few drops of dilute iodine solution were then added to each tube. Test tube B turned deep blue-black, while test tube A showed almost no colour change.
- 1 markWhy did test tube A show almost no colour change with iodine?
(A) Saliva destroyed the iodine solution(B) The starch in tube A had already been broken down into simple sugar by salivary amylase(C) Tube A never had any starch in it to begin with(D) Iodine does not react with starch at body temperature
Passage
A doctor recorded a patient’s blood pressure during a routine check-up. The reading taken during the contraction of the ventricles was 150 mm Hg, and the reading taken during the relaxation of the ventricles was 95 mm Hg, both well above the normal range.
- 1 markWhat are the two blood pressure readings described in the passage called?
(A) Diastolic and systolic(B) Systolic and diastolic(C) Arterial and venous(D) Atrial and ventricular
9 True / False
True / False
- 1 mark(A) Xylem transports water and minerals only in the upward direction.
(B) Phloem can transport food both upward and downward.
(A) A true, B true(B) A false, B true(C) A true, B false(D) A false, B false
Answer Key and Explanations
Direct Questions
- (B) Chloroplasts are the cell organelles containing chlorophyll, and photosynthesis takes place inside them.
- (C) Saliva contains the enzyme salivary amylase, which breaks down starch (a complex molecule) into simple sugar.
- (C) In every organism and every pathway, glucose (6-carbon) first breaks down to pyruvate (3-carbon) in the cytoplasm.
- (D) Aerobic respiration (breakdown of pyruvate using oxygen) takes place in the mitochondria.
- (C) Arteries carry blood away from the heart; because this blood is under high pressure, arteries have thick, elastic walls.
- (C) Oxygen-rich blood from the lungs enters the thin-walled left atrium first.
- (C) The nephron is the kidney’s basic filtration unit; Bowman’s capsule is only one part of it.
- (B) Bacterial cells together with food particles stick to the teeth to form dental plaque, which blocks saliva from reaching the tooth surface to neutralise the acid that causes decay.
- (B) Cilia line the upper respiratory tract and remove germs, dust and other harmful particles from inhaled air; smoking destroys these cilia.
- (B) Unlike Amoeba, Paramoecium has a definite cell shape and takes in food at a specific spot; cilia covering its entire surface beat and move food to that spot.
- (A) When we breathe in, we lift our ribs and flatten our diaphragm, which enlarges the chest cavity so air is sucked into the lungs.
Assertion-Reason
- (C) A is true: fermentation in yeast does give ethanol and CO2. R is false: anaerobic respiration happens in the cytoplasm, not the mitochondria (mitochondria is where the aerobic pathway happens).
- (A) Both are true and R explains A: the book says separating the two sides of the heart gives a highly efficient oxygen supply, which is useful in animals with high energy needs, such as birds and mammals, that constantly use energy to maintain body temperature. (Double circulation itself is found in all vertebrates other than fish; it is the complete separation that birds and mammals add.)
Match the Following
- (B) Salivary glands: salivary amylase (iii); Stomach: HCl and pepsin (iv); Pancreas: trypsin and lipase (i); Small intestine wall: intestinal juice (ii). This order is option (B).
- (C) Artery: carries blood away from the heart (iii); Vein: has valves (iv); Capillary: one-cell-thick wall (ii); Platelet: plugs a leak by clotting (i). This order is option (C).
Statement-Based Questions
- (A) Both statements are true, and II correctly explains I: the extra time needed to digest cellulose is exactly why herbivores need a longer small intestine.
- (A) Both are true, and II correctly explains why transpiration pull dominates during the day: open stomata let water evaporate quickly, creating the suction that drives xylem transport.
Arrange in the Correct Order
- (A) Starting from blood coming back from the body: it enters the right atrium (iii), the right ventricle pumps it to the lungs (i), oxygenated blood returns from the lungs to the left atrium (iv), and the left ventricle pumps it to the body (ii): iii-i-iv-ii, option (A).
- (B) Haemoglobin first takes up oxygen in the lungs (ii) and releases it to a tissue that is short of oxygen (iv); inside the cell, pyruvate is broken down using this oxygen in the mitochondria, giving carbon dioxide and water (i); the carbon dioxide is then carried, mostly dissolved in the blood, to the alveoli and released (iii): ii-iv-i-iii, option (B).
Fill in the Blanks
- (B) The book names urea or uric acid as the nitrogenous waste products the kidneys filter out of the blood.
- (B) This is the book’s own definition of transpiration.
Odd One Out
- (A) Amphibians, birds and reptiles all show double circulation, blood passing through the heart twice per body cycle. Fish are the exception: blood passes through their two-chambered heart only once per cycle (single circulation).
Passage-Based Questions
- (B) Saliva’s enzyme, salivary amylase, had already converted the starch in tube A into simple sugar, so there was no starch left to give the blue-black colour with iodine.
- (B) The reading taken during ventricular contraction is the systolic pressure (150 mm Hg here); the reading taken during ventricular relaxation is the diastolic pressure (95 mm Hg here).
True / False
- (A) Both statements are true: xylem moves water/minerals upward only, while phloem moves food in whichever direction the plant needs it, upward or downward.
More for this chapter