NEET BIOLOGY

Detailed explanation-1: -This type of tropism is called gravitropism. For example, the roots of most plants exhibit positive gravitropism when they grow downward. Shown is a colour photograph of a cross-section of grass with roots growing down into soil. A strip of green grass stretches across the photograph near the top.

Detailed explanation-2: -Phototropism (response to light), geotropism (response to gravity), chemotropism (response to specific substances), hydrotropism (response to water), thigmotropism (response to mechanical stimulation), traumatotropism (response to wound lesion), and galvanotropism (response to electricity) are all examples of tropism.

Detailed explanation-3: -What are examples of Tropic movement? Stems usually grow towards light (positive phototropism) while roots grow away from light (negative phototropism).

Detailed explanation-4: -Growth toward or away from a stimulus is known as a tropism. You might have noticed that plants bend toward the light. This is an example of a tropism where light is the stimulus, known as phototropism (Figure below). To obtain more light for photosynthesis, leaves and stems grow toward the light.

Detailed explanation-5: -An example of plants responding to gravity is the fact that roots grow towards the earth and shoots grow away from the earth. This bidirectional growth is influenced by gravity, and is therefore called gravitropism.