The growth of plant seedlings is usually A. phototropic and gravitropic
B. thigmotropic and gravitropic
C. phototropic and influenced by ethylene
D. gravitropic and influenced by ethylene

The correct answer is - A. phototropic and gravitropic.

Explanation:

A plant seedling grows usually two-direction shoots or stems towards light and roots towards the soil or in the direction of gravity. The movement of the plant toward a specific stimulus or effect parts is called tropism and different parts move in a different direction.

The movement of the roots of the plant is usually towards the direction of soil or gravity and this is called gravitropic. The shoot or stem grows from the seedling towards the direction of light and it is called phototropic.

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what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.