Botanica

Lab Quiz I 

1. If guard cells in a plant were deficient in K+, which of the following would be most likely to occur?

|  a.
| Wilting would become more likely.
|
|  b.
|Photosynthesis would decrease.
|
|  c.
| Transpiration would increase.
|
|  d.
| Food transport would decrease.
|
Correct! Water follows the K+ into the guard cells; if there is little K+ in theguard cells, they will lose water, the stomata will close, and less CO2 will be available for photosynthesis.

2. What tissue is indicated by label line 1?

|  a.
| phloem
|
|  b.
|mesophyll
|
|  c.
| epidermis
|
|  d.
| xylem
|
Correct! The correct answer is c.

3. Which line indicates a guard cell?

|  a.
| 1
|
|  b.
| 2
|
|  c.
| 3
|
| d.
| 4
|
|  e.
| 5
|
Correct! The correct answer is d.

4. Which type of cells are indicated by label line 2?

|  a.
| parenchyma
|
|  b.
| xylem
|
|  c.
| phloem
||  d.
| epidermis
|
Correct! The correct answer is b.

5. Several factors account for the movement of water up xylem vessels. Which single factor is most important in pulling water towardthe top of a tall tree?

|  a.
| Evaporation of water through stomata
|
|  b.
| Osmosis in the root
|
|  c.
| Capillary action
|
|  d.
| Atmospheric pressure
|
Correct! Itis this evaporation that provides the transpirational pull to move water to the top of a tall tree.

6. All of the following enhance water transport in terrestrial plants EXCEPT:

|  a.
|Hydrogen bonds linking water molecules
|
|  b.
| Capillary action due to adhesion of water molecules to the walls of xylem
|
|  c.
| Evaporation of water from the leaves
|
|  d.
|K+ being transported out of the guard cells
|
Correct! When K+ leave the guard cells, water follows, the guard cells become flaccid, and the stomata close. As a result, transpiration doesn't take...