Question

A plant bends toward the light source on the right. What is the best explanation?

A.
The light stimulates growth on the right side compared to the left, and the plant bends right.

B.
The light stimulates growth on the left side compared to the right, and the plant bends right.

C.
The light stimulates growth on the right side compared to the left, and the plant bends left.

D.
The light stimulates growth on the left side compared to the right, and the plant bends left.

Answer 1

A.

The light stimulates growth on the right side compared to the left, and the plant bends right.

Using grass and grain seedlings he proved that the cells on the dark side of the plant (the side away from a light source) elongate causing the seedling to bend towards the light source. Auxins A plant hormone called indolacetic acid or auxin is responsible for making plant cells on the side away from light elongate.