question_answer 2)

Justify the following statements on the basis of external features (a) Underground parts of a plant are not always roots. (b) Rower is a modified shoot.  

Answer:

(a) Underground parts of a plant are not always roots, they are subterranean stems which do not have root hairs and root cap.     Have terminal bud, nodes and internodes. Have leaves on the nodes. Most of the underground stems such as sucker, rhizome, corm, tubers, bulb, etc., store food, form aerial shoots. (b) Flower is a modified shoot because (i) It possess nodes and internodes. (ii) It may develop in the axil of small leaf-like structure called bract. (iii) Flowers get modified into bulbils or fleshy buds in some plants. (iv) Anatomically the pedicel and thalamus of a flower resemble that of stem. (v) The vascular supply of different organs of flower resemble that of normal leaves. (vi) In the flower of Degeneria, the stamens are expanded like leaves and the carpels appear tike folded leaves.