Fig. 5.1 shows drawings of two flowers, labelled P and Q, which were taken from two different species of wild plant. The two plants are not pollinated in th...
Question 1 Report
Fig. 5.1 shows drawings of two flowers, labelled P and Q, which were taken from two different species of wild plant. The two plants are not pollinated in the same way: one of them relies on insects to carry its pollen from flower to flower, while the other relies on the wind to blow its pollen through the air. Flowers that use these two different methods of pollination usually look quite different from one another. Features such as the size and colour of the petals, and the position of the anthers and the stigmas, all give clues about how a particular flower is pollinated. Both flowers have been drawn to a similar scale so that these features can be compared.
(a) State which flower, P or Q, is pollinated by wind, and give one visible feature from Fig. 5.1 that supports your answer. [2]
(b) Describe how the stigma of the wind-pollinated flower is adapted to its method of pollination. [3]
(c) Explain why wind-pollinated flowers produce very large numbers of pollen grains. [3]
Answer Details
(a) The wind-pollinated flower is Q [1]. One visible supporting feature (any one): its anthers hang outside the flower, it has a large feathery stigma outside the flower, or it has small green petals [1] - all features suited to releasing or catching pollen carried on the wind, rather than attracting insects. [2]
(b) The stigma of a wind-pollinated flower is adapted by being (1 mark each, max 3): large with a big surface area; feathery / branched; and hanging outside the flower, so that it catches pollen grains blown through the air. [3]
(c) Wind carries pollen randomly in all directions [1], so most of the pollen is wasted and never lands on a stigma [1]; producing very large numbers of grains raises the chance that at least some reach a stigma of the same species, allowing successful pollination [1]. [3]
Download The App On Google Playstore
Everything you need to excel in your exams
