What is the primary role of the phloem in plants?

A. Transporting water and minerals from roots to leaves.

B. Transporting organic compounds from sources to sinks.

C. Facilitating gas exchange for photosynthesis.

D. Storing nutrients for later use.

How does active transport contribute to the loading of sugars into the phloem sieve tubes?

A. It facilitates the passive diffusion of sugars into the sieve tubes.

B. It uses ATP to actively load sugars, creating a high solute concentration.

C. It decreases the solute concentration in the sieve tubes.

D. It prevents the uptake of water by osmosis.

What drives the flow of sap in the phloem from the source to the sink?

A. Gravitational pull.

B. Transpiration pull.

C. Hydrostatic pressure gradient.

D. Active transport of water.

Why does water enter the phloem at the source site?

A. Decreased solute concentration in the phloem.

B. Increased hydrostatic pressure in the phloem.

C. High concentration of solutes in the phloem leads to water uptake by osmosis.

D. Active transport of water into the phloem.

Which of the following is true regarding the transport of solutes in the phloem?

A. Solutes move from areas of low pressure to areas of high pressure.

B. The incompressibility of water does not affect solute transport.

C. Solutes are transported along hydrostatic pressure gradients.

D. Active transport is not involved in solute loading into the phloem.

a) Explain how plants transport organic compounds like sugars from their production sites (sources) to where they are used or stored (sinks) via phloem. [4]

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

a) Elucidate how the incompressibility of water allows solutes to be transported in the phloem along hydrostatic pressure gradients. [3]

b) How does a high concentration of solutes in the phloem at the source site lead to water uptake by osmosis? [2]

a) Discuss the significance of hydrostatic pressure gradients in the transport of solutes in the phloem of plants. [4]

b) How do environmental factors influence the rate of translocation of solutes in the phloem? Provide examples. [3]

a) Describe the process of translocation in plants and explain how it is essential for the distribution of nutrients. [4]

b) How does the cohesion-tension theory relate to the transport of water in plants? [3]

c) Discuss the impact of environmental factors on the rate of translocation in plants. [3]

a) Explain the role of active transport in loading sugars into the phloem. Why is ATP necessary for this process? [4]

b) How does the incompressibility of water facilitate the transport of solutes in the phloem? [3]

c) Discuss the mutualistic relationships between flowering plants and pollinators and their significance for plant reproduction. [3]

What is the consequence of a high concentration of solutes in the phloem at the source?

A. Decreased water potential leading to water loss by osmosis.

B. Increased water potential leading to water uptake by osmosis.

C. Decreased hydrostatic pressure in the phloem.

D. Inhibition of active transport of sugars into the phloem.

How does the incompressibility of water contribute to solute transport in the phloem?

A. It prevents the formation of hydrostatic pressure gradients.

B. It allows solutes to be transported along hydrostatic pressure gradients.

C. It inhibits the active loading of sugars into the phloem.

D. It decreases the solute concentration in the phloem at the source.

What energy form is primarily used for loading sugars into the phloem sieve tubes at the source?

A. Kinetic energy

B. Potential energy

C. ATP

D. Light energy

Which of the following best describes the movement of organic compounds in plants?

A. From sinks to sources via the xylem.

B. From sources to sinks via the phloem.

C. From sources to sinks via the xylem.

D. From sinks to sources via the phloem.

Why is the process of loading sugars into the phloem at the source essential for plant survival?

A. It decreases the solute concentration in the phloem.

B. It facilitates the transport of water from sinks to sources.

C. It drives the flow of sap from sources to sinks, distributing nutrients.

D. It prevents the uptake of water by osmosis at the source.

a) How does water uptake by osmosis at the source site influence the hydrostatic pressure in the phloem? [3]

b) Elucidate the role of hydrostatic pressure gradients in the movement of sap from the source to the sink. [4]

c) How do changes in environmental conditions, such as temperature, affect the process of translocation? [3]

a) Discuss the significance of the active uptake of mineral ions at the root hair cells for overall water transport in plants. [4]

b) How does the cohesion-tension theory explain water transport against gravity in plants? [3]

c) Explain the concept of photoperiodism and its role in triggering flowering in different types of plants. [3]

a) Explain the process by which sugars are actively transported into the phloem sieve tubes at the source. Why is this process essential for phloem transport? [4]

b) Discuss the role of hydrostatic pressure in driving the flow of sap from the source to the sink. How is this pressure generated and maintained? [4]

c) How does the incompressibility of water contribute to the transport of solutes in the phloem? [3]

d) Elaborate on how environmental factors such as light intensity and temperature can influence the rate of translocation in plants. [4]

a) Describe the significance of osmosis in maintaining hydrostatic pressure within the phloem. [4]

b) How does the active uptake of mineral ions at the root hair cells contribute to water transport in plants? [3]

c) Explain the cohesion-tension theory and its relevance to the transport of water in plants. [4]

d) Discuss the mutualistic relationships between plants and pollinators and how they benefit biodiversity. [4]

a) Elucidate the role of ATP in the active transport of sugars into the phloem. [3]

b) How does a high concentration of solutes in the phloem at the source site lead to water uptake by osmosis? [4]

c) Discuss how changes in environmental conditions, such as humidity, can affect the process of translocation in plants. [4]

d) Explain the concept of photoperiodism and its significance in the flowering of different types of plants. [4]