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(i) Draw a diagram showing… (Class 10 Science 2024, Q35B)

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

CBSE Class 10 Science 2024: question 35(B)

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

Q35(B) · 5 marks · Long answerHow do Organisms Reproduce?

(i) Draw a diagram showing spore formation in Rhizopus and label the (a) reproductive and (b) non-reproductive parts. Why does Rhizopus not multiply on a dry slice of bread ?
(ii) Name and explain the process by which reproduction takes place in Hydra.

Figure in the paper: Students are asked to draw a diagram of spore formation in Rhizopus (sporangiophore with sporangium and related structures) and label reproductive and non-reproductive parts. See it in the official paper.

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

Hints

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

Hint 1

The black dots on mouldy bread are the spore-containing structures; the threads beneath are the body.

Hint 2

Spores need a damp surface to grow. In Hydra, a small outgrowth appears on the body and later separates.

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) Diagram: draw Rhizopus on bread showing thread-like hyphae spread on the surface, with upright sporangiophores bearing round sporangia full of spores at their tips.

    1 mark

  2. (a) Reproductive part: sporangium (containing spores).

    ½ mark

  3. (b) Non-reproductive part: hyphae.

    ½ mark

  4. Rhizopus does not grow on dry bread because its spores need moisture and nutrients to germinate and multiply, and dry bread lacks moisture.

    1 mark

  5. (ii) Process: Budding (asexual reproduction).

    1 mark

  6. Explanation: in Hydra, regenerative cells divide repeatedly at one specific site to form an outgrowth called a bud. The bud develops into a tiny individual and, when mature, detaches from the parent to live as a new Hydra. (Hydra can also regenerate: each cut piece grows into a whole new organism.)

    1 mark

Answer: (i) Reproductive: sporangium; non-reproductive: hyphae; dry bread lacks the moisture needed for spores to germinate; (ii) budding: a bud forms by repeated cell division, grows and detaches

Where the marks are

  • Neat diagram of Rhizopus (1 mark)
  • Labels sporangium (½ mark) and hyphae (½ mark)
  • Reason: dry bread lacks moisture/nutrients for germination (1 mark)
  • Names budding or regeneration (1 mark)
  • Correct explanation of the process (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from How do Organisms Reproduce?, one at a time, marked against the answer key and marking points.Back to the full paper2024 board paper, set 31/1/1: 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.