Identify A, B, C and D parts in the given diagram of an Angiospermic ovule and give the fate of each part after fertilization: [Figure: L.S. of an anatropous ovule with two integuments around the nucellus and embryo sac; the micropyle faces downward…

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Q.28 Identify A, B, C and D parts in the given diagram of an Angiospermic ovule and give the fate of each part after fertilization: [Figure: L.S. of an anatropous ovule with two integuments around the nucellus and embryo sac; the micropyle faces downward beside the funicle. A points to the inner layer at the micropylar end, B to the outer layer, C to the cells at the micropylar end of the embryo sac (egg apparatus), and D to the nucleus in the centre of the embryo sac.]

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Answer: LabelPartFate after fertilisation AInner integumentForms the tegmen (inner seed coat). BOuter integumentForms the testa (outer seed coat). CEgg cell (egg apparatus)Egg fuses with one male gamete (syngamy) to form the diploid zygote (oospore), which develops into the embryo. The synergids degenerate. DSecondary nucleus (fused polar nuclei, 2n) in the central cellFuses with the second male gamete (triple fusion) to form the triploid primary endosperm nucleus, which forms the endosperm. Also, the ovule as a whole becomes the seed and the micropyle remains as the micropyle of the seed. (If A is read as the micropyle, its fate is the micropyle of the seed, through which water enters during germination.)

Identify A, B, C and D parts in the given diagram of an Angiospermic ovule and give the fate of each part after fertilization: [Figure: L.S. of an anatropous ovule with two integuments around the nucellus and embryo sac; the micropyle faces downward…

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Label	Part	Fate after fertilisation
A	Inner integument	Forms the tegmen (inner seed coat).
B	Outer integument	Forms the testa (outer seed coat).
C	Egg cell (egg apparatus)	Egg fuses with one male gamete (syngamy) to form the diploid zygote (oospore), which develops into the embryo. The synergids degenerate.
D	Secondary nucleus (fused polar nuclei, 2n) in the central cell	Fuses with the second male gamete (triple fusion) to form the triploid primary endosperm nucleus, which forms the endosperm.