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Draw a neat diagram of… (Class 12 Biology 2026, Q25)

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BiologyCBSE Class 12 · Board exam 2026, set 57/1/1 · 3 marks · Diagram

CBSE Class 12 Biology 2026: question 25

Set in the CBSE Class 12 board exam of 2026, paper 57/1/1, section C, question 25, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q25 · 3 marks · DiagramSexual Reproduction in Flowering Plants

Draw a neat diagram of megasporangium of an angiosperm and label any six parts. (½ × 6 = 3)

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 57/1/1.

Hints

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

Hint 1

A megasporangium is the ovule. Most angiosperm ovules are anatropous (inverted).

Hint 2

Work outwards from the embryo sac: nucellus, integuments, then the openings and the stalk.

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. Draw an anatropous ovule in L.S.: an oval body curved back so that the micropyle lies close to the stalk. Label any six of the parts below.

  2. Funicle: the stalk attaching the ovule to the placenta. Hilum: the junction where the body of the ovule fuses with the funicle.

    1 mark

  3. Outer and inner integuments: two protective layers around the nucellus. Micropyle: the small opening at the tip of the integuments, next to the funicle.

    1 mark

  4. Nucellus: the mass of cells enclosed by the integuments. Embryo sac (female gametophyte): inside the nucellus, showing the egg apparatus (egg cell plus 2 synergids) at the micropylar end, 2 polar nuclei in the centre and 3 antipodals at the chalazal end. Chalaza: the basal part of the ovule, opposite the micropyle.

    1 mark

Answer: Labelled L.S. of an anatropous ovule showing funicle, hilum, micropyle, outer and inner integuments, nucellus, embryo sac and chalaza (any six)

Where the marks are

  • Each correctly labelled part of the ovule (½ × 6 = 3 marks)

Revise the chapter

Practise this chapterBoard-style questions from Sexual Reproduction in Flowering Plants, one at a time, marked against the answer key and marking points.Back to the full paper2026 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.