gerakan pada tumbuhan

What is phototropism and how does it benefit plants?

• Phototropism is the process of plants growing in the dark, allowing them to thrive in low-light conditions.

• Phototropism refers to the ability of plants to grow roots deeper into the soil, enhancing nutrient absorption.

• Phototropism is the growth of plants towards light, benefiting them by maximizing photosynthesis.

• Phototropism is the growth of plants away from light, which helps them conserve energy.

Describe the role of auxins in phototropism.

• Auxins inhibit growth on the light-exposed side of the plant.

• Auxins have no effect on plant directionality.

• Auxins cause leaves to fall off in response to light.

• Auxins promote cell elongation on the shaded side of the plant, causing it to bend towards the light.

What is gravitropism and how do roots and shoots respond to gravity?

• Gravitropism is the process of plants reproducing; roots and shoots do not respond to gravity.

• Gravitropism refers to the ability of plants to absorb water; roots grow sideways and shoots grow downward.

• Gravitropism is the response of plants to sunlight; roots grow upward and shoots grow downward.

• Gravitropism is the growth response of plants to gravity; roots grow downward (positive gravitropism) and shoots grow upward (negative gravitropism).

Explain the difference between positive and negative gravitropism.

• Negative gravitropism is growth towards gravity (stems)

• Both types of gravitropism occur in the same direction

• Positive gravitropism is growth towards gravity (roots), and negative gravitropism is growth away from gravity (stems and leaves).

• Positive gravitropism is growth away from gravity (roots)

What is thigmotropism and which plants exhibit this response?

• Thigmotropism is found in aquatic plants such as lilies and lotus.

• Thigmotropism is a type of photosynthesis in cacti and succulents.

• Thigmotropism is exhibited by climbing plants such as vines, peas, and some species of beans.

• Thigmotropism is a response to light in plants like sunflowers.

How do tendrils of climbing plants demonstrate thigmotropism?

• Tendrils only grow in the absence of obstacles.

• Tendrils curl around objects when they touch them, demonstrating thigmotropism.

• Tendrils change color when they encounter objects.

• Tendrils grow straight without any response to touch.

Define hydrotropism and its significance for plant survival.

• Hydrotropism refers to the movement of plants in response to gravity.

• Hydrotropism is the growth of plant roots towards moisture, significant for plant survival as it helps them locate water sources.

• Hydrotropism is the process of plants absorbing nutrients from the soil.

• Hydrotropism is the growth of leaves towards sunlight.

How do roots sense moisture gradients in the soil?

• Roots sense moisture gradients by detecting changes in water availability and growing towards wetter areas.

• Roots rely solely on temperature changes to find water.

• Roots absorb moisture directly from the air.

• Roots do not respond to moisture levels in the soil.

What are nastic movements and how do they differ from tropisms?

• Nastic movements are always directional responses to light.

• Tropisms are non-directional responses to temperature changes.

• Nastic movements involve growth towards a stimulus while tropisms do not.

• Nastic movements are non-directional responses to stimuli, while tropisms are directional growth responses.

Give an example of a plant that exhibits nastic movements and describe the mechanism involved.

• Cactus (Opuntia) does not exhibit nastic movements.

• Mimosa pudica (sensitive plant) exhibits nastic movements.

• Sunflower (Helianthus) shows rapid growth but no nastic movements.

• Oak tree (Quercus) has fixed leaves and does not exhibit nastic movements.