Chapter 29 - Plant Structure Flashcards Preview

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Flashcards in Chapter 29 - Plant Structure Deck (43):
1

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

water loss

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?

from root to leaf

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 _____.

decline; decrease

4

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

soil water; surface water

5

Land plants are descended from:

green algae.

6

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

transpiration.

7

CAM photosynthesis improves the CO2/H2O exchange ratio because:

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

8

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

stomata.

9

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

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

10

Which of the following statements about transpiration is TRUE?

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

11

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

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

12

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

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

13

Unlike xylem, phloem is made up of cells:

That are still metabolically active.

14

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

xylem.

15

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

lignin

16

Which of the following statements BEST defines cavitation?

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

17

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

They consume more carbohydrates than they produce

18

Vascular plants store most carbohydrate reserves as:

starch

19

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

parenchyma cells: transport of water

20

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

true

21

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

true

22

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

The fungicide destroys mycorrhizal symbionts.

23

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

Root nodules

24

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

prokaryotes

25

Nitrogen fixation:

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

26

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

solute composition; selective uptake by the endodermis

27

All of the following are vascular plants except:

green algae

28

Where do mesophyll cells usually obtain CO2 for photosynthesis?

from the air spaces that surround them

29

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

lignin

30

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

CO2 and water; the soil

31

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

roots

32

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

xylem

33

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

parenchyma cells: transport of water

34

Root activities are all passive, requiring no additional energy.

False

35

Xylem transports _____, whereas phloem transports _____.

water; sugars

36

Which of the following is true of transport in phloem?

It is driven by turgor pressure

37

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

true

38

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

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

39

Water flows from vessel to vessel through "pits" that contain:

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

40

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

False

41

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

False

42

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

Casparian strip.

43

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

absorbing water into the root hair