State four features of flowers pollinated by insects.

Explanation

Adaptations of insect pollinated flowers :
(i) These flowers are large and brightly coloured. If the flowers are small they are grouped into large conspicuous inflorescence to attract insects. e.g., Sunflower and other flowers of Compositae family.
(ii) If the flower is small and inconspicuous, the bracts may become large and colourful which help to attract insects, e.g., Bougain villea.
(iii) Insects and flowers both benefit from their specialized symbiotic relationships, plants are pollinated while insects obtain valuable sources of food.
(iv) Nectar guides are present at the base of the petals, so that insects coming in search of nectar have to put their proboscis and head into the center of the flower e.g., petunia.
(v) The pollen grains of such flowers are sticky or have spinous outgrowths on the exine, their stigmas are also sticky and rough.
(vi) Guidelines are present on petals, lever mechanism is also present.