Question

question 8
kristen observes that a potted plant that has been left on a table for several days appears to be growing toward a nearby window. she knows that auxins are plant hormones involved in cell growth. which hypothesis best explains kristens observation?
select one:
○ a. auxins are stimulating more rapid cell growth in the lit side of the stem, causing the plant to bend toward the light.
○ b. auxins are stimulating more rapid cell growth in the shaded side of the stem, causing the plant to bend toward the light.
○ c. auxins are inhibiting cell growth in the shaded side of the stem, causing the plant to bend toward the light.
○ d. auxins are inhibiting cell growth and increasing turgor pressure in the stem, causing the plant to bend toward the light.

Explanation:

This is about phototropism, a plant response to light. Auxins move to the shaded side of the stem, where they stimulate faster cell elongation. The longer cells on the shaded side make the stem bend toward the light source. Option a is incorrect because auxins accumulate on the shaded, not lit, side. Option c is wrong because auxins promote, not inhibit, growth on the shaded side. Option d is incorrect as auxins do not inhibit growth here, and turgor pressure is not the main driver of this bending.

Answer:

b. Auxins are stimulating more rapid cell growth in the shaded side of the stem, causing the plant to bend toward the light.