What allows plants to exhibit indeterminate growth and continuously form new organs and tissues?

A. Differentiation of cells in the root apical meristem.

B. Presence of undifferentiated cells in the plant meristems.

C. Elongation of cells in the vascular tissue.

D. Absence of plant hormones in the shoot apex.

How does mitotic cell division in the shoot apical meristem contribute to plant growth?

A. It provides cells for root extension and nutrient absorption.

B. It inhibits the production of plant hormones.

C. It provides cells necessary for stem extension and leaf development.

D. It leads to the differentiation of vascular tissue.

Which plant hormones are primarily involved in regulating cell division, elongation, and differentiation in the shoot apex?

A. Abscisic acid, ethylene, and jasmonic acid.

B. Auxins, gibberellins, and cytokinins.

C. Salicylic acid, brassinosteroids, and strigolactones.

D. Florigen, traumatin, and systemin.

What is the role of auxin efflux pumps in plant growth and development?

A. They prevent the formation of auxin concentration gradients in plant tissues.

B. They set up concentration gradients of auxin in plant tissues, directing growth.

C. They inhibit the active transport of auxin into the cell wall.

D. They decrease the sensitivity of plant tissues to auxin.

How does auxin affect cell growth rates in plants?

A. By decreasing the pattern of gene expression.

B. By inhibiting the production of proteins involved in cell wall modification.

C. By changing the pattern of gene expression, leading to the production of growth-related proteins.

D. By disrupting the concentration gradients of auxin in plant tissues.

a) Explain how the presence of undifferentiated cells in plant meristems contributes to indeterminate growth and the continuous formation of new organs and tissues. [4]

b) Discuss how mitotic cell division in the shoot apical meristem is essential for stem extension and leaf development. [3]

a) Detail the role of plant hormones such as auxins, gibberellins, and cytokinins in regulating cell division, elongation, and differentiation in the shoot apex. [4]

b) How do auxin efflux pumps contribute to setting up concentration gradients of auxin in plant tissues, and how does this affect the direction of plant growth and development? [3]

a) Discuss plant tropisms, including phototropism, gravitropism, and thigmotropism, and explain how they enable plants to adapt to their environment. [4]

b) How does auxin affect cell growth rates by altering the pattern of gene expression, and what is the significance of this in plant growth? [3]

a) Explain the concept of indeterminate growth in plants and how it differs from determinate growth in animals. [3]

b) How do undifferentiated cells in the meristems contribute to the continuous formation of new tissues and organs in plants? [4]

c) Discuss the significance of the shoot apical meristem in stem extension and leaf development. [3]

a) Detail the roles of auxins, gibberellins, and cytokinins in plant growth, focusing on their impact on cell division and elongation. [4]

b) How do plant tropisms, including phototropism and gravitropism, enable plants to optimise their growth in response to environmental conditions? [3]

c) Explain the mechanism by which auxin efflux pumps establish auxin concentration gradients and their influence on plant development. [3]

What is phototropism and how does it benefit plants?

A. Growth in response to touch, allowing plants to avoid obstacles.

B. Growth towards light, enhancing photosynthesis and energy capture.

C. Growth in response to gravity, aiding in root anchorage.

D. Growth away from light, reducing exposure to harmful UV rays.

How do plants exhibit gravitropism?

A. By growing towards light sources.

B. By growing in response to touch stimuli.

C. By growing in response to gravity, aiding in upward shoot growth and downward root growth.

D. By growing away from areas of high auxin concentration.

What is the significance of undifferentiated cells in plant meristems?

A. They lead to the termination of plant growth.

B. They contribute to the ageing of plant tissues.

C. They allow for the continuous formation of new organs and tissues.

D. They inhibit the action of plant hormones.

How do plant hormones like auxins contribute to tropisms in plants?

A. By inhibiting cell elongation on the side of the stimulus.

B. By promoting cell elongation on the side away from the stimulus.

C. By evenly distributing auxin throughout the plant tissue.

D. By decreasing the sensitivity of plant cells to environmental stimuli.

Which of the following best describes the role of auxins in plant cell growth?

A. They decrease cell wall flexibility, inhibiting growth.

B. They alter gene expression patterns, leading to the production of proteins for cell wall modification.

C. They prevent the establishment of auxin concentration gradients.

D. They inhibit the activity of auxin efflux pumps.

a) Discuss the role of active transport in loading sugars into phloem sieve tubes and why it requires energy in the form of ATP. [3]

b) How does the incompressibility of water facilitate the transport of solutes in the phloem along hydrostatic pressure gradients? [4]

c) Explain the significance of hydrostatic pressure in driving the flow of sap from source to sink. [3]

a) How does auxin affect the pattern of gene expression in plant cells, and what proteins are produced as a result? [3]

b) Discuss the role of these proteins in cell wall modification and growth. [3]

c) Explain how changes in cell wall properties contribute to the direction of plant growth and development. [4]

a) Explain the concept of indeterminate growth in plants and how the presence of meristems contributes to this type of growth. [3]

b) Discuss the role of the shoot apical meristem in plant growth, particularly in stem extension and leaf development. [4]

c) How do plant hormones such as auxins, gibberellins, and cytokinins regulate growth at the shoot apex? [4]

d) Describe the mechanism of phototropism and explain how it allows plants to adapt to their environment. [3]

a) Detail how auxin efflux pumps contribute to the establishment of auxin concentration gradients in plant tissues. [3]

b) Explain how these gradients of auxin influence the direction of plant growth and development. [4]

c) Discuss gravitropism and its significance in plant adaptation to the environment. [3]

d) How does the active uptake of mineral ions at the root hair cells contribute to overall plant growth? [4]

a) Discuss the role of mitotic cell division in the shoot apical meristem and its significance in plant growth. [4]

b) How do auxins affect cell growth rates and contribute to cell wall modification? [3]

c) Explain the concept of thigmotropism and discuss its importance for plants. [3]

d) How does the incompressibility of water contribute to the transport of solutes in the phloem? [4]