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Answer the following. (Class 12 Biology 2024, Q24)

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BiologyCBSE Class 12 · Board exam 2024, set 57/1/1 · 3 marks · Short answer

CBSE Class 12 Biology 2024: question 24

Set in the CBSE Class 12 board exam of 2024, paper 57/1/1, section C, question 24, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q24 · 3 marks · Short answerEvolution

Answer the following.

  1. (a)

    Explain the significance of the experiment carried out by S.L. Miller. Name the scientists whose hypothesis prompted him to carry out this experiment.

    2 marks
  2. (b)

    How does meteorite analysis favour this hypothesis ?

    1 mark

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 57/1/1.

Hints

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

Hint 1

What did Miller find in his flask after electric sparking of CH₄, NH₃, H₂ and water vapour?

Hint 2

Two scientists, one Russian and one British, proposed that life arose from non-living organic molecules.

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) In 1953, S.L. Miller created early-earth conditions in a closed flask containing CH, H, NH and water vapour at 800°C, and passed electric discharges through it. Amino acids were formed.

    ½ mark

  2. (a) Significance: the experiment showed that organic molecules can form from inorganic molecules under primitive earth conditions. It thus supported the theory of chemical evolution of life.

    1 mark

  3. (a) The hypothesis was proposed by Oparin and Haldane.

    1 mark

  4. (b) Analysis of meteorites revealed similar organic compounds. This indicates that similar chemical processes occur elsewhere in space, which supports the hypothesis.

    ½ mark

Answer: (a) Showed formation of amino acids from inorganic gases, supporting chemical evolution; Oparin and Haldane; (b) meteorites contain similar compounds, so similar processes occur in space

Where the marks are

  • Miller's set-up produced amino acids (½ mark)
  • Proved chemical evolution / organic from inorganic (1 mark)
  • Oparin and Haldane (½ + ½ marks)
  • Meteorites contain similar compounds, so similar processes occur in space (½ mark)

Revise the chapter

  • Chapter: Evolution (notes, formulas, where marks are lost and every past question)
Practise this chapterBoard-style questions from Evolution, one at a time, marked against the answer key and marking points.Back to the full paper2024 board paper, set 57/1/1: 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.