What physical characteristic do plants exhibit in response to light?

Plants exhibit a phenomenon known as phototropism, which is the growth response towards a light source. When exposed to light, certain growth hormones within the plant, such as auxins, redistribute themselves to the shaded side of the plant. This uneven distribution causes the cells on that side to elongate more than those on the side exposed to light, leading to the plant bending or growing towards the light. This adaptation enhances the plant's ability to capture sunlight for photosynthesis, ultimately promoting its growth and survival.

The other options do not accurately reflect typical plant behavior in response to light. Shrinking in size or growing taller only at night does not align with the fundamental aspects of plant growth as influenced by light conditions. Moreover, stating that plants have no specific growth pattern fails to acknowledge the clear and scientific responses plants have to environmental stimuli, especially light.