Question

Geotropic response of root is due to

• A. Higher auxin content of stem
• B. Higher growth on upper side of root
• C. Lower rate of growth in the stem
• D. Higher rate of growth in the stem

Answer 1

The correct option is B Higher growth on upper side of root

Auxin is a plant hormone that plays important role in the growth of stem and roots to gravity. Gravitropism is a plant growth response to gravity. Root shows positive gravitropism and shoot shows negative gravitropism. Auxin content is lower on the upper side and more concentration occurs in lower side of the root and stem. This stimulates stem elongation and thus stem grows upwards. In roots, higher growth on upper side occurs due to lower auxin content. This inhibits root elongation and thus root grows downwards showing geotropic response.

Thus, the correct answer is option B.