Question 1

Which of the following best explains why leaves appear green to the human eye?

Accepted Answer

Leaves reflect green light and absorb red and blue light.

Question 2

Which of the following is a function of root hairs in plants?

Accepted Answer

Increasing the surface area for water and mineral absorption

Question 3

A potato is classified as which of the following plant organs?

Accepted Answer

Modified stem

Question 4

Which ground tissue cell type is primarily responsible for photosynthesis in leaves?

Accepted Answer

Parenchyma

Question 5

Which of the following best describes the process of diffusion in plant cells?

Accepted Answer

Movement of substances across a membrane down their concentration gradient without energy input

Question 6

What is the main driving force for the upward movement of water in the xylem during transpiration?

Accepted Answer

Negative pressure (tension) created by evaporation from leaves

Question 7

Which equation correctly represents water potential ($$\Psi) in $$plant cells?

Accepted Answer

$$\Psi = \Psi_s + \Psi_p$$

Question 8

Which of the following statements about phloem transport is correct?

Accepted Answer

Phloem transport is driven by pressure differences between source and sink regions.

Question 9

Which plant hormone is primarily responsible for promoting cell elongation and is used as a synthetic herbicide?

Accepted Answer

Auxin

Question 10

A plant is exposed to drought conditions. Which hormone is most likely to increase in concentration to help the plant conserve water?

Accepted Answer

Abscisic acid (ABA)

Question 11

Which of the following best describes the role of guard cells in plant leaves?

Accepted Answer

They regulate the opening and closing of stomata to control gas exchange.

Question 12

Which of the following is a correct statement about the cohesion-tension theory of water transport?

Accepted Answer

Water molecules stick together by cohesion and are pulled upward by transpiration.

Question 13

Which of the following is NOT a function of the cuticle on plant leaves?

Accepted Answer

Facilitating gas exchange

Question 14

Which of the following best describes the function of sclerenchyma cells in plants?

Accepted Answer

Providing structural support with thick, lignified walls

Question 15

A plant is placed in an environment with high salt concentration. What is the most likely effect on its water potential ($$\Psi$$)?

Accepted Answer

$$\Psi$$ will decrease, making water uptake more difficult.

Question 16

Which of the following best explains why transpiration is important for plants?

Accepted Answer

It helps transport water and minerals from roots to leaves.

Question 17

Which of the following is a real-world example of phototropism?

Accepted Answer

A sunflower stem bending toward sunlight

Question 18

Which of the following best describes the role of phytochrome in plants?

Accepted Answer

It is a light receptor sensitive to red and far-red light, regulating flowering and circadian rhythms.

Question 19

Which of the following is a correct statement about the movement of sugars in plants?

Accepted Answer

Sugars move from source to sink via the phloem.

Question 20

Which of the following best explains why some plants close their stomata during the day in hot, dry environments?

Accepted Answer

To reduce water loss through transpiration

Plant Structure, Growth, and Responses: Study Notes for Biology 106

Study Guide - Practice Questions