Question

The plant shoot cells on the shady side grow longer than the cells exposed to light because

• A. plants grow in the direction of light
• B. light is essential for the photosynthesis of green plants
• C. accumulation of auxin on the shaded side stimulates cell elongation
• D. light induces plant cells on the lighted surface to grow quicker

Answer 1

The correct option is C accumulation of auxin on the shaded side stimulates cell elongation

Auxin is a plant growth hormone that causes cell elongation and regulates the growth of the shoot. In a differentially illuminated plant, auxin accumulates in the shaded part, creating elongation of the cells in the shaded region. This irregular elongation on two sides makes the plant curve or bend towards the light source, i.e., phototropic curvature. Hence, the plant shoot cells on the shady side grow longer than the cells exposed to light because of accumulation of auxin on the shaded side which stimulates cell elongation.