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Kidneys are vital organs for… (Class 10 Science 2024, Q38)

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ScienceCBSE Class 10 · Board exam 2024, set 31/4/1 · 4 marks · Case-based

CBSE Class 10 Science 2024: question 38

Set in the CBSE Class 10 board exam of 2024, paper 31/4/1, section E, question 38, for 4 marks. Try it first; the hints and our step-by-step solution are below.

Q38 · 4 marks · Case-basedCompetency-basedLife Processes

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.

  1. (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.

    1 mark
  2. (b)

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

    1 mark
  3. (c)(i)

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

    2 marks

  4. 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.

    2 marks

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 31/4/1.

Hints

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

Hint 1

Think of the blood vessel that carries blood into the kidney, and the capillary knot inside the cup-shaped capsule.

Hint 2

The bladder is muscular – can you consciously hold urine?

Hint 3

Urine formation first separates substances from the blood and then takes the useful ones back. Where in the nephron does the taking back happen?

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. (a)(i) The renal artery brings oxygenated blood to the kidney.

    ½ mark

  2. (a)(ii) The cluster of thin-walled capillaries inside Bowman's capsule is the glomerulus.

    ½ mark

  3. (b) Urine is stored in the urinary bladder.

    ½ mark

  4. (b) The bladder is muscular and under nervous control, so we can control the urge to pass urine.

    ½ mark

  5. (c)(i) Step 1, glomerular filtration: in the glomerulus, blood is filtered under pressure into Bowman's capsule.

    ½ mark

  6. (c)(i) Function: it removes nitrogenous wastes such as urea and uric acid from the blood, along with water, glucose, amino acids and salts.

    ½ mark

  7. (c)(i) Step 2, selective (tubular) reabsorption: the filtrate flows through the tubule.

    ½ mark

  8. (c)(i) Function: useful substances such as glucose, amino acids, salts and a major amount of water are taken back into the surrounding blood capillaries. What remains becomes urine.

    ½ mark

  9. (c)(ii) Selective reabsorption takes place in the tubular part of the nephron.

    1 mark

  10. (c)(ii) The amount of water reabsorbed depends on:

    • how much excess water there is in the body;
    • how much dissolved waste has to be excreted.
    1 mark

Answer: (a) (i) Renal artery (ii) Glomerulus; (b) Urinary bladder, nervous control; (c)(i) Filtration – removes urea and other wastes from blood; reabsorption – returns glucose, amino acids, salts and water to blood; (c)(ii) Tubular part of the nephron; depends on excess water in the body and the amount of dissolved waste to be excreted

Where the marks are

  • Renal artery (½ mark)
  • Glomerulus (½ mark)
  • Urinary bladder (½ mark)
  • Nervous control (½ mark)
  • Filtration named with its function (½ + ½ mark)
  • Reabsorption named with its function (½ + ½ mark)
  • Tubular part of the nephron (1 mark)
  • Two factors: excess water in the body and amount of dissolved waste (½ + ½ mark)

Revise the chapter

  • Chapter: Life Processes (notes, formulas, where marks are lost and every past question)
Practise this chapterBoard-style questions from Life Processes, one at a time, marked against the answer key and marking points.Back to the full paper2024 board paper, set 31/4/1: 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.