Chapter 29 - Plant Structure

Question 1

Plants have developed BOTH cuticles and crassulacean acid metabolism (CAM) in an attempt to limit which of the following?

Answer 1

water loss

Question 2

In which direction would phloem sap flow if there were a greater concentration of sucrose molecules in the root phloem compared with the leaf phloem?

Answer 2

from root to leaf

Question 3

Assuming the stomata are open to the same degree, the rate of transpiration should _____ on a rainy day compared with a sunny day because the H2O concentration gradient from the inside to the outside of the leaf would _____.

Answer 3

decline; decrease

Question 4

Vascular plants hydrate photosynthetic cells using _____, whereas bryophytes do so using _____.

Answer 4

soil water; surface water

Question 5

Land plants are descended from:

Answer 5

green algae.

Question 6

Plants lose a great deal of water from their leaves in a process referred to as:

Answer 6

transpiration.

Question 7

CAM photosynthesis improves the CO2/H2O exchange ratio because:

Answer 7

CO2 capture occurs at night when the gradient for diffusion of H2O out of the leaf is smaller.

Question 8

The structure(s) that allow(s) gasses, such as CO2, to diffuse into and out of a leaf is/are the:

Answer 8

stomata.

Question 9

Guard cells can actively increase their volume and, therefore, size by:

Answer 9

increasing the amount of solutes, such as K+ and Cl–.

Question 10

Which of the following statements about transpiration is TRUE?

Answer 10

Transpiration sets in motion the movement of water from the roots to the leaves.

Question 11

What happens to the tension in the xylem when the stomata close and evaporation stops?

Answer 11

It drops to a value closer to that of the water-filled pores in the soil.

Question 12

If water molecules (H2O) suddenly stopped forming hydrogen bonds with each other, how would water transport in vascular plants change (if at all)?

Answer 12

It would stop, because water transport relies on H2O molecules being connected by hydrogen bonds.

Question 13

Unlike xylem, phloem is made up of cells:

Answer 13

That are still metabolically active.

Question 14

Water is transported from the soil to the leaves in the:

Answer 14

xylem.

Question 15

Which of the following substances helps make cells of xylem rigid to avoid collapse?

Answer 15

lignin

Question 16

Which of the following statements BEST defines cavitation?

Answer 16

Cavitation is the formation and expansion of gas bubbles in the xylem

Question 17

Why may young leaves that are just emerging from the bud be considered “sinks” for phloem transport?

Answer 17

They consume more carbohydrates than they produce

Question 18

Vascular plants store most carbohydrate reserves as:

Answer 18

starch

Question 19

Which of the following are NOT a correct match of cells and their function?

Answer 19

parenchyma cells: transport of water

Question 20

Carbohydrates are stored in the roots, but they may also be released into the surrounding soil, where they feed the microbial community

Answer 20

true

Question 21

A companion cell supports a sieve element by performing specific cellular processes.

Answer 21

true

Question 22

Applying fungicides to plants may result in a phosphorus deficiency. What is the MOST likely explanation for this observation?

Answer 22

The fungicide destroys mycorrhizal symbionts.

Question 23

_____ are the structures formed by roots that house nitrogen-fixing bacteria.

Answer 23

Root nodules

Question 24

Before the development of the Haber-Bosch process, NH3 could be produced from N2 only by:

Answer 24

prokaryotes

Question 25

Nitrogen fixation:

Answer 25

converts N2 to ammonia, making it available for incorporation into amino acids and nucleotides.

Question 26

Xylem sap and soil water differ in _____ because of _____.

Answer 26

solute composition; selective uptake by the endodermis

Question 27

All of the following are vascular plants except:

Answer 27

green algae

Question 28

Where do mesophyll cells usually obtain CO2 for photosynthesis?

Answer 28

from the air spaces that surround them

Question 29

Which of the following substances helps make cells of xylem rigid to avoid collapse?

Answer 29

lignin

Question 30

The carbon, hydrogen, and oxygen in a plant body come from _____, whereas the majority of other elements come from ______.

Answer 30

CO2 and water; the soil

Question 31

Which of the following are not part of the shoot system?

Answer 31

roots

Question 32

Water is transported from the soil to the leaves in the:

Answer 32

xylem

Question 33

Which of the following are not a correct match of cells and their function?

Answer 33

parenchyma cells: transport of water

Question 34

Root activities are all passive, requiring no additional energy.

Answer 34

False

Question 35

Xylem transports _____, whereas phloem transports _____.

Answer 35

water; sugars

Question 36

Which of the following is true of transport in phloem?

Answer 36

It is driven by turgor pressure

Question 37

Plants that have symbioses with nitrogen-fixing bacteria provide these bacteria with food in the form of carbohydrates.

Answer 37

true

Question 38

How do bryophytes avoid damage to their tissues from a dry environment?

Answer 38

Their membranes are able to withstand the desiccation and rehydration of the cells without rupturing.

Question 39

Water flows from vessel to vessel through “pits” that contain:

Answer 39

the cell walls that separated the neighbouring cells as they grew.

Question 40

Although plants expend metabolic energy to move both water and carbohydrates between leaves and roots, the transportation of water requires slightly more energy.

Answer 40

False

Question 41

Xylem is able to extract water from soil because it is in direct contact with the soil.

Answer 41

False

Question 42

At the endodermis is a thin band of hydrophobic material that prevents water passage between cells called the:

Answer 42

Casparian strip.

Question 43

Which of the following activities in the roots does not require energy?

Answer 43

absorbing water into the root hair