What term describes the growth of plant portions towards or away from gravity?

Geotropism, also known as gravitropism, refers to the orientation of a plant in response to gravity. In this process, roots typically grow downward, which is termed positive geotropism, while stems and shoots tend to grow upward, exhibiting negative geotropism. This response is crucial for the plant's ability to anchor itself in the soil and enables it to access essential resources such as water and nutrients.

Other terms mentioned refer to different types of growth responses. Phototropism relates to plant growth in response to light, where plants tend to bend towards light sources. Thigmotropism involves growth in response to touch or physical contact, a common response seen in climbing plants. Hydrotropism describes how plant roots grow toward moisture in the soil. Each of these terms highlights distinct environmental stimuli, but geotropism specifically addresses the influence of gravity on plant growth orientation.