Fig. 1 shows a half-section through a flower of a crop plant. The parts labelled A, B, C, D and E are important in reproduction. (a) Name the parts labelled...

Labelled answer diagram:

(a) The parts of the flower labelled in Fig. 1 are:

• A - Anther [1]. The anther produces pollen grains, which contain the male gametes. It is the upper part of the stamen.
• B - Stigma [1]. The stigma is the receptive surface at the top of the carpel where pollen grains land during pollination. In insect-pollinated flowers it is often sticky.
• C - Ovary [1]. The ovary is the swollen base of the carpel that contains the ovules. After fertilisation it develops into the fruit.
• D - Ovule [1]. The ovule is found inside the ovary and contains the female gamete (egg cell). After fertilisation it develops into the seed.
• E - Petal [1]. Petals are often brightly coloured and scented in insect-pollinated flowers to attract pollinators.

(b) Pollination in an insect-pollinated flower occurs as follows:

1. An insect (such as a bee or butterfly) visits the flower, attracted by the brightly coloured petals, scent, or nectar [1].
2. As the insect feeds or collects nectar, pollen grains from the anther stick to its body (legs, abdomen, or head) [1].
3. When the insect moves to another flower of the same species, pollen grains are transferred from its body onto the stigma, completing pollination [1].

This process is called cross-pollination when pollen is transferred between different plants, which promotes genetic variation in the offspring.