In a typical flower, germinating pollen grains pass through several parts of the gynoecium before they reach the ovule. A list of the parts of gynoecium is given below in different combinations. Choose the combination that represents the correct sequence of pollen tube pathway/journey:
- (a)Style, Stigma, Ovary
- (b)Stigma, Style, Ovary
- (c)Pistil, Stigma, Ovary
- (d)Ovary, Pistil, Style
Correct — B, Stigma, Style, Ovary. Pollination deposits pollen grains on the stigma, the receptive tip of the gynoecium. Each grain germinates there and sends out a pollen tube that grows down through the style (the slender connecting stalk) and enters the ovary at the base, where it delivers the male gametes to the ovule. So the pollen tube's journey is Stigma → Style → Ovary.
- (a)Style, Stigma, Ovary — This reverses the first two steps: the pollen lands on the stigma first and only then travels down the style, not the other way round.
- (c)Pistil, Stigma, Ovary — 'Pistil' is another name for the whole gynoecium (stigma + style + ovary together), not a separate stage, so it cannot be the first step in a sequence of its own parts.
- (d)Ovary, Pistil, Style — This starts at the ovary (the destination) and again lists 'pistil', the entire unit; the order is both inverted and includes the whole structure as a part.
The gynoecium — the female part of a flower — is made of one or more pistils, each with three regions: the stigma (pollen-receiving tip), the style (connecting stalk) and the ovary (base, containing ovules). After pollination the pollen tube grows from stigma through style into the ovary to reach the ovule for fertilisation.
The distractors work by inverting the order and by slipping in 'pistil', which is the whole organ rather than a stage. Fix the top-to-bottom anatomy — stigma on top, ovary at the base — and the sequence follows.
- Parts of a pistil, top to bottom: stigma → style → ovary (containing ovules).
- Pollen lands on the stigma, germinates and grows a pollen tube down the style.
- The pollen tube enters the ovary and delivers the male gametes to the ovule.
- 'Pistil' is the whole gynoecium unit, not a single region.
- Confusing 'pistil' (the whole gynoecium) with a single part in the sequence.
- Reversing stigma and style — pollen always lands on the stigma first.
Asked as the correct sequence of pollen-tube travel, or by labelling stigma/style/ovary on a flower diagram.
No directly related past PYQ was found.
- practice — not a real PYQ
In a flower, pollen grains are received on which part of the pistil?
- (a)Style
- (b)Stigma
- (c)Ovary
- (d)Ovule
Answer(b) Stigma — the receptive tip where pollen lands and germinates.
- practice — not a real PYQ
The ovules of a flower are contained in the
- (a)Stigma
- (b)Style
- (c)Ovary
- (d)Anther
Answer(c) Ovary — the swollen base of the pistil that holds the ovules.