Question 1

Which of the following best explains why desert plants, such as the one shown in the first image, have evolved thick, reduced leaves?

Accepted Answer

To reduce water loss by minimizing the surface area exposed to the environment

Question 2

In the context of water movement in plants, which equation correctly represents water potential ($$\Psi) $$and its components?

Accepted Answer

$$\Psi = \psi_p + \psi_s$$

Question 3

A plant cell is placed in a solution with a lower water potential than the cell's cytoplasm. What will most likely happen to the cell?

Accepted Answer

The cell will undergo plasmolysis as water leaves the cell

Question 4

Which of the following is a primary function of mycorrhizae, as shown in the image with roots and fungus?

Accepted Answer

To increase the plant's ability to absorb water and minerals

Question 5

Which route allows substances to move through the cell walls and intercellular spaces without crossing the plasma membrane?

Accepted Answer

Apoplastic route

Question 6

What is the main driving force for the bulk flow of water in the xylem from roots to leaves?

Accepted Answer

Transpiration pull due to evaporation of water from leaves

Question 7

Which of the following best describes the cohesion-tension hypothesis for water transport in plants?

Accepted Answer

Water is pulled upward by negative pressure generated by transpiration at the leaf surface

Question 8

A plant is exposed to high temperatures and wind. Which hormone is most likely to be produced to help the plant conserve water, and what is its effect?

Accepted Answer

Abscisic acid; closes stomata

Question 9

Which of the following statements about phloem transport is correct?

Accepted Answer

Phloem sap moves from source to sink, driven by positive pressure

Question 10

A plant cell has a solute potential ($$\psi_s) of$$ $$-0.7$$ MPa and a pressure potential ($$\psi_p) of$$ $$0.5$$ MPa. What is the water potential ($$\Psi) of $$the cell?

Accepted Answer

$$\Psi = -0.2$$ MPa

Question 11

Which adaptation would you expect to find in a xerophyte (desert plant) to minimize water loss?

Accepted Answer

Thick cuticle and reduced leaf surface area

Question 12

Which process is responsible for the opening of stomata in response to light?

Accepted Answer

Active transport of K$$^+$$ ions into guard cells, followed by water influx

Question 13

A plant wilts when water is not available. What is the primary cause of wilting at the cellular level?

Accepted Answer

Loss of turgor pressure in plant cells

Question 14

Which of the following best describes the role of companion cells in phloem?

Accepted Answer

They assist sieve-tube elements with metabolic functions

Question 15

Which of the following scenarios would most likely result in guttation in a plant?

Accepted Answer

Root pressure forcing water out of hydathodes at night

Question 16

Which of the following is NOT a trigger for stomatal opening?

Accepted Answer

High abscisic acid concentration

Question 17

Which of the following best explains why alternate phyllotaxy is advantageous in low light environments?

Accepted Answer

It minimizes leaf overlap, allowing more light to reach lower leaves

Question 18

Which of the following is a consequence of cavitation in the xylem?

Accepted Answer

Formation of air bubbles that block water flow

Question 19

Which of the following best describes the movement of sugars in the phloem?

Accepted Answer

From source to sink, driven by positive pressure

Question 20

Which of the following is a real-world application of understanding water potential in agriculture?

Accepted Answer

Determining the direction of water movement to optimize irrigation practices

Resource Acquisition and Transport in Vascular Plants

Study Guide - Practice Questions

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