Stomata are small openings present in a epidermis of leaves. The stomata are bound by guard cells. Mention the role off guard cells in stomatalmechanism.

Read the following statements carefully and select the appropriate option given below. (i) Reproduction is defined as a biological process in which an organism gives rise to the young ones (offspring) similar to itself. (ii) Adventitious buds arise from the notches present at margins of leaves of Bryophyllum. (iii) Asexual reproduction is common among single celled organisms, and in plants and animals with relatively simple organisations. (iv) A few plants exhibit unusual flowering phenomenon, some of them such as bamboo species flower only once in their life time, generally after 50-100 years. (v) The events of asexual reproduction though elaborate and complex, follow a regular sequence.