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Answer the following. (Science 2024 31/2/1 Q35a)

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ScienceCBSE Class 10 · Board exam 2024, set 31/2/1 · 5 marks · Long answer

CBSE Class 10 Science 2024: question 35(a)

Set in the CBSE Class 10 board exam of 2024, paper 31/2/1, section D, question 35(a), for 5 marks. Try it first; the hints and our step-by-step solution are below.

Q35(a) · 5 marks · Long answerControl and Coordination

Answer the following.

  1. (i)

    Distinguish between hormonal co-ordination in plants and animals.

    0 marks
  2. (ii)

    Which part of the brain is responsible for – (1) intelligence (2) riding a bicycle (3) vomiting (4) controlling hunger

    0 marks
  3. (iii)

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

    0 marks

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 31/2/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

Compare how a hormone travels and where it is made in a plant and in an animal.

Hint 2

Higher thinking is done by the forebrain. Balance and posture belong to the hindbrain, which also has a centre for involuntary actions.

Hint 3

Think of the bony structures that enclose the brain and the spinal cord.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. (i) Difference 1: In plants, hormones reach the target cells by simple diffusion, from cell to cell. In animals, hormones are carried by the blood to distant target organs.

    1 mark

  2. (i) Difference 2: In plants, there are no specialised glands; hormones are made in growing regions such as the root and shoot tips. In animals, hormones are secreted by specialised endocrine glands such as the thyroid and pituitary.

    1 mark

  3. (ii)(1) Intelligence: cerebrum (forebrain).

    ½ mark

  4. (ii)(2) Riding a bicycle, which needs balance, posture and precise voluntary movement: cerebellum (hindbrain).

    ½ mark

  5. (ii)(3) Vomiting, an involuntary action: medulla oblongata (hindbrain).

    ½ mark

  6. (ii)(4) Controlling hunger: hypothalamus (forebrain).

    ½ mark

  7. (iii) The brain lies inside a bony box, the skull (cranium). It is also cushioned by a fluid-filled balloon (cerebrospinal fluid within the membranes), which absorbs shocks.

    ½ mark

  8. (iii) The spinal cord is enclosed and protected by the vertebral column (backbone).

    ½ mark

Answer: (i) Plants: diffusion, no glands; animals: blood transport, endocrine glands. (ii) (1) cerebrum (2) cerebellum (3) medulla (4) hypothalamus. (iii) Brain: skull + fluid-filled balloon; spinal cord: vertebral column

Where the marks are

  • Any two correct differences between plant and animal hormonal coordination (1 + 1 marks)
  • Cerebrum, cerebellum, medulla, hypothalamus correctly matched (½ mark each)
  • Brain protected by the skull/cranium with a fluid cushion (½ mark)
  • Spinal cord protected by the vertebral column (½ mark)

Revise the chapter

Practise this chapterBoard-style questions from Control and Coordination, one at a time, marked against the answer key and marking points.Back to the full paper2024 board paper, set 31/2/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.