Biology · Sample Paper 2

General instructions

Section A · Objective

1. Question 11 mark

   The basic unit of classification is

   1. A.genus
   2. B.species
   3. C.family
   4. D.order
2. Question 21 mark

   The five-kingdom classification was proposed by

   1. A.Linnaeus
   2. B.R.H. Whittaker
   3. C.Darwin
   4. D.Haeckel
3. Question 31 mark

   In gymnosperms, the seeds are

   1. A.enclosed in fruit
   2. B.naked
   3. C.absent
   4. D.formed in sporangia only
4. Question 41 mark

   Which phylum has animals with a pseudocoelom?

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

   A flower with both stamens and carpels is called

   1. A.unisexual
   2. B.bisexual
   3. C.sterile
   4. D.neuter
6. Question 61 mark

   Vascular bundles in a monocot stem are

   1. A.arranged in a ring and open
   2. B.scattered and closed
   3. C.radial
   4. D.absent
7. Question 71 mark

   The site of protein synthesis in a cell is the

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

   Which of the following is a polysaccharide made of glucose units and found in plant cell walls?

   1. A.glycogen
   2. B.starch
   3. C.cellulose
   4. D.chitin
9. Question 91 mark

   DNA replication occurs in which phase of the cell cycle?

   1. A.G₁
   2. B.S
   3. C.G₂
   4. D.M
10. Question 101 mark

    The primary CO₂ acceptor in the Calvin cycle is

    1. A.PEP
    2. B.RuBP
    3. C.OAA
    4. D.PGA
11. Question 111 mark

    The exchange of gases in the lungs takes place in the

    1. A.trachea
    2. B.bronchi
    3. C.alveoli
    4. D.pharynx
12. Question 121 mark

    The joint between the atlas and axis vertebrae is a

    1. A.hinge joint
    2. B.pivot joint
    3. C.ball and socket joint
    4. D.saddle joint
13. Question 131 mark

    Assertion (A): Enzymes lower the activation energy of a reaction.

    Reason (R): Enzymes are consumed in the reactions they catalyse.

    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): C₄ plants are more efficient in hot, dry climates.

    Reason (R): C₄ plants show very little photorespiration because CO₂ is concentrated around RuBisCO in bundle sheath cells.

    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): Veins have valves.

    Reason (R): Valves prevent the backflow of blood flowing at low pressure.

    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): The pituitary is called the master gland.

    Reason (R): It secretes hormones that control several other endocrine glands.

    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

   Name two characteristics of fungi and one disease caused by them.

2. Question 182 marks

   Give two modifications of the stem with one example each.

3. Question 192 marks

   Name the four basic types of animal tissue and one function of each.

4. Question 202 marks

   What is ultrafiltration? Where does it take place in the nephron?

5. OR

   Question 202 marks

   State two functions each of the cerebellum and medulla oblongata.

6. Question 212 marks

   Name the plant hormone responsible for (i) apical dominance (ii) breaking seed dormancy (iii) closing of stomata (iv) delaying senescence.

Section C · Short answer

1. Question 223 marks

   Give three distinguishing features of chordates compared with non-chordates.

2. Question 233 marks

   Describe the internal structure of a dicot root with reference to its vascular bundles and pericycle.

3. Question 243 marks

   Give three differences between mitosis and meiosis.

4. Question 253 marks

   Differentiate between aerobic respiration and fermentation, giving three points.

5. OR

   Question 253 marks

   Explain the light reaction of photosynthesis — photolysis of water, cyclic and non-cyclic photophosphorylation.

6. Question 263 marks

   Explain how oxygen is transported in the blood. What is the oxygen dissociation curve?

7. Question 273 marks

   What is double circulation? Explain its significance.

8. Question 283 marks

   Name the hormones secreted by the adrenal cortex and medulla. Why are adrenaline and noradrenaline called 'emergency hormones'?

Section D · Case-based

1. Question 294 marks

   Case study — Kidney failure. Mr Rao, aged 60, has diabetes and high blood pressure. Tests show high levels of urea and creatinine in his blood. His doctor says his kidneys are failing and advises haemodialysis while he waits for a kidney transplant.

   (i) Why does urea accumulate in the blood when the kidneys fail? (1 mark)

   (ii) What is the medical term for accumulation of urea in blood? (1 mark)

   (iii) Explain the principle of haemodialysis. (2 marks)

   OR

   (iii) Name two hormones that help regulate kidney function and state their role. (2 marks)

2. Question 304 marks

   Case study — Joint pain. Mrs Lata, aged 55, complains of stiff, painful and swollen joints, especially in the morning. Her son, who plays football, has developed severe muscle cramps after a long match. The doctor says both conditions affect the musculo-skeletal system but have different causes.

   (i) Name the disorder Mrs Lata is likely suffering from. (1 mark)

   (ii) What causes muscle cramps or fatigue after strenuous exercise? (1 mark)

   (iii) Explain the sliding filament theory of muscle contraction. (2 marks)

   OR

   (iii) What is osteoporosis? Give two ways to prevent it. (2 marks)

Section E · Long answer

1. Question 315 marks

   Describe the structure and functions of (a) mitochondria (b) chloroplast. Why are they called semi-autonomous organelles?

2. Question 325 marks

   Describe the structure of the human eye with a labelled diagram (labels acceptable). How is an image formed and perceived?

3. OR

   Question 325 marks

   Explain the generation and conduction of a nerve impulse along a myelinated axon.

4. Question 335 marks

   Describe the structure of proteins at primary, secondary, tertiary and quaternary levels. Give one example of a protein with quaternary structure.