Question

1. what causes differential growth in stem plant cells?

thigmotropystarcheselongationauxins

Explanation:

Auxins are plant hormones that play a crucial role in regulating plant growth. They cause differential growth in stem plant cells by promoting cell elongation on the shaded side of the stem. This differential elongation leads to the bending of the stem towards the light source (phototropism). Thigmotropism is a response to touch, starches are storage molecules, and elongation is a result of auxin action rather than the cause of differential growth.

Answer:

auxins