Doug plants a few peas. after two days, he sees the shoot and the root forming. he observes that the shoot grows upward, toward the light. the root grows downward, into the soil. why do these embryonic organs grow in a specific direction?

Shoot exhibits negative geotropism and positive phototropism while roots exhibit positive geotropism and negative phototropism

Explanation:

Growth movements towards or away from stimulus are called tropic movements. Shoot grow in the direction of sunlight (positive phototropism) and away from the gravity of the earth (negative geotropism). This is why shoot exhibits upward growth in a seedling.

On the other hand, roots grow away from sunlight (negative phototropism) and towards the gravity of earth (positive geotropism). Since the force of gravity attracts the objects towards the center of the earth, roots exhibit downward growth into the soil.  

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