CBSE Class 10 Science 2023 · Paper 31/6/3 · Question 35

(a) The two types are self-pollination and cross-pollination. In self-pollination the pollen is transferred from the stamen to the stigma of the same flower, so it does not have to be carried to another flower, and the offspring show less variation. In cross-pollination the pollen is transferred from one flower to the stigma of another, usually on a different plant of the same species; it needs an agent such as wind, water or animals, and when it brings together gametes from two different plants the offspring show more variation. (b) After fertilisation the zygote divides several times to form an embryo within the ovule; the ovule develops a tough coat and is gradually converted into a seed; and the ovary grows rapidly and ripens to form a fruit. Meanwhile the petals, sepals, stamens, style and stigma may shrivel and fall off. (c) (i) A, the plumule, gives rise to the future shoot. (ii) B, the radicle, gives rise to the future root system. (iii) C, the cotyledon, stores food.