Arvind sometimes go for late evening walk with his father who has a background of biology. While walking in the colony park, he observed many plants having colour flowers. He also saw few plants having white flowers. Most of these flowers emit pleasant fragrance (=aroma). out of curiousty, Arvind asked his futher the following questions:
(i) Why do plants have variously coloured folowers ? GIve two reasons.
(ii) Why do certain flowers emit fragrance ? How does fragrance of flowers sperad in the environment ?
(iii) Which scientific phenomenon is involved when (a) fragrance spreads in the house at the time of coking of food in the kitchen, (b) exchange of gases occurs acorss the respiratory surface.

Explanation

(i) (a) Plants have variously colured flowers to attrct insects and other animals for pollination. Coloured flowers attract diumal insects such as honeybees and butterflies. While white flowers atteact noetural insects such as moths.
(b) The flowers are ment for sexualy reproduction in plants.
(ii) Flowers contain nectar and spread fragrance in the environment to attract insects and other animals for lollination.
Scent/fragrance spreads from flowers into surrounding environment throhg diffusion.
(iii) (a) Diffusion
(b) Diffusion.