Biology · Sample Paper 3

General instructions

Section A · Objective

1. Question 11 mark

   A place where living plants are grown for study and reference is a

   1. A.herbarium
   2. B.botanical garden
   3. C.museum
   4. D.zoo
2. Question 21 mark

   Which kingdom includes all unicellular eukaryotes?

   1. A.Monera
   2. B.Protista
   3. C.Fungi
   4. D.Plantae
3. Question 31 mark

   Which plant group is called the 'amphibians of the plant kingdom'?

   1. A.algae
   2. B.bryophytes
   3. C.pteridophytes
   4. D.gymnosperms
4. Question 41 mark

   Animals with jointed appendages belong to

   1. A.Annelida
   2. B.Arthropoda
   3. C.Mollusca
   4. D.Echinodermata
5. Question 51 mark

   A flower that can be divided into two equal halves in only one plane is

   1. A.actinomorphic
   2. B.zygomorphic
   3. C.asymmetric
   4. D.regular
6. Question 61 mark

   The tissue that gives mechanical support and has lignified walls is

   1. A.parenchyma
   2. B.collenchyma
   3. C.sclerenchyma
   4. D.phloem
7. Question 71 mark

   The cell organelle with its own DNA besides the nucleus is

   1. A.Golgi body
   2. B.mitochondrion
   3. C.lysosome
   4. D.ribosome
8. Question 81 mark

   Which of these is a nucleoside?

   1. A.adenine
   2. B.adenosine
   3. C.adenylic acid
   4. D.ATP
9. Question 91 mark

   The number of chromosomes is halved during

   1. A.mitosis
   2. B.meiosis I
   3. C.meiosis II
   4. D.interphase
10. Question 101 mark

    The products of the light reaction used in the Calvin cycle are

    1. A.ATP and NADPH
    2. B.O₂ and water
    3. C.glucose and ATP
    4. D.CO₂ and NADH
11. Question 111 mark

    The number of ATP molecules produced per glucose in aerobic respiration is about

    1. A.2
    2. B.8
    3. C.36–38
    4. D.100
12. Question 121 mark

    The hormone used to induce rooting in stem cuttings is

    1. A.auxin
    2. B.ethylene
    3. C.ABA
    4. D.cytokinin
13. Question 131 mark

    Assertion (A): Oxygen diffuses from alveoli into blood.

    Reason (R): The partial pressure of oxygen in the alveoli is higher than in deoxygenated blood.

    1. A.Both Assertion (A) and Reason (R) are true, and R is the correct explanation of A.
    2. B.Both Assertion (A) and Reason (R) are true, but R is not the correct explanation of A.
    3. C.Assertion (A) is true, but Reason (R) is false.
    4. D.Assertion (A) is false, but Reason (R) is true.
14. Question 141 mark

    Assertion (A): Mammals excrete urea.

    Reason (R): Urea is less toxic than ammonia and needs less water to be removed.

    1. A.Both Assertion (A) and Reason (R) are true, and R is the correct explanation of A.
    2. B.Both Assertion (A) and Reason (R) are true, but R is not the correct explanation of A.
    3. C.Assertion (A) is true, but Reason (R) is false.
    4. D.Assertion (A) is false, but Reason (R) is true.
15. Question 151 mark

    Assertion (A): Red muscle fibres can work for long periods.

    Reason (R): Red fibres have a high myoglobin content and many mitochondria for aerobic respiration.

    1. A.Both Assertion (A) and Reason (R) are true, and R is the correct explanation of A.
    2. B.Both Assertion (A) and Reason (R) are true, but R is not the correct explanation of A.
    3. C.Assertion (A) is true, but Reason (R) is false.
    4. D.Assertion (A) is false, but Reason (R) is true.
16. Question 161 mark

    Assertion (A): Insulin lowers blood glucose.

    Reason (R): Insulin is secreted by the alpha cells of the pancreas.

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

Section B · Very short answer

1. Question 172 marks

   Differentiate between gymnosperms and angiosperms (two points).

2. Question 182 marks

   What are the functions of the Golgi apparatus? (Two points.)

3. Question 192 marks

   What is lymph? Give two of its functions.

4. Question 202 marks

   Differentiate between myelinated and non-myelinated nerve fibres.

5. OR

   Question 202 marks

   Define inspiratory capacity and expiratory capacity.

6. Question 212 marks

   Give two features each of class Aves.

Section C · Short answer

1. Question 223 marks

   Explain three types of root modifications with one example each.

2. Question 233 marks

   Distinguish between dicot and monocot leaves on three bases.

3. Question 243 marks

   Explain the 'lock and key' and 'induced fit' models of enzyme action.

4. Question 253 marks

   What is photoperiodism? Classify plants on the basis of photoperiod with examples.

5. OR

   Question 253 marks

   Explain the electron transport system and oxidative phosphorylation.

6. Question 263 marks

   Describe the role of the liver, lungs and skin in excretion.

7. Question 273 marks

   Name the hormones of the thyroid and parathyroid glands and their functions.

8. Question 283 marks

   Name the three types of joints with one example each.

Section D · Case-based

1. Question 294 marks

   Case study — High blood pressure. Mr Sharma, aged 50, often gets headaches. His doctor measures his blood pressure as 150/95 mm Hg and diagnoses hypertension. He also warns that untreated hypertension can lead to coronary artery disease.

   (i) What is the normal blood pressure of a healthy adult? (1 mark)

   (ii) What do 150 and 95 represent? (1 mark)

   (iii) What is coronary artery disease? How can it be prevented? (2 marks)

   OR

   (iii) What is angina pectoris? (2 marks)

2. Question 304 marks

   Case study — Onion root tips. Students observe onion root tips under a microscope after staining. They count 200 cells: 170 are in interphase, 18 in prophase, 6 in metaphase, 4 in anaphase and 2 in telophase.

   (i) Why are root tips used to study mitosis? (1 mark)

   (ii) Which stage is the longest? How do you know? (1 mark)

   (iii) Describe the main events of metaphase and anaphase. (2 marks)

   OR

   (iii) What happens in the S phase and G₂ phase of interphase? (2 marks)

Section E · Long answer

1. Question 315 marks

   Describe the Hatch–Slack (C₄) pathway. How is it different from the C₃ pathway?

2. Question 325 marks

   Describe the human respiratory system with a labelled (described) diagram. Explain how breathing is regulated.

3. OR

   Question 325 marks

   Describe the structure of the human ear and explain the mechanism of hearing.

4. Question 335 marks

   Describe the five-kingdom classification. Give two features and one example of each kingdom.