BY 124 Worksheet 5 ; Chapter 36
1. What type of phyllotaxy minimizes shading of lower leaves?
a. spiral (or alternate) phyllotaxy with an angle of 167.5 degrees between each leafb. whorled phyllotaxy
c. spiral (or alternate) phyllotaxy with an angle of 137.5 degrees between each leaf
d. opposite phyllotaxy
e. spiral (or alternate) phyllotaxy with an angle of 97.5 degrees between each leaf
2. How might roots react when they encounter a region of the soil that is low in nitrates?
a. produce additional proteins for transporting and assimilating the available nitratesb. increase mycorrhizal associations so as to increase nitrate absorption
c. branch extensively so as to maximize the ability to absorb whatever nitrates are available
d. produce additional root hairs to facilitate nitrate absorption
e. minimize branching
3. The purpose of the xylem is to ______.
a. transport water and minerals from roots to shootsb. transport sugar from sources to sinks
c. transport water and minerals from shoots to roots
d. increase root surface area for water and mineral absorption
e. transport sugar from sinks to sources
4. The proton pump in plant cells ______.
a. generates energy by producing ATPb. pumps H+ into the cell
c. provides energy for active transport
d. pumps H+ out of the cell
e. moves H+ and nitrate into the cell
5. A plant cell placed in a solution with a higher water potential will ______.
a. lose water and plasmolyzeb. gain water and plasmolyze
c. gain water and become turgid
d. lose water and become turgid
e. lose water and crenate
6. The water potential of a cell is defined by the equation Ψ = ΨS + ΨP. Which of the following statements is true?
a. ΨS may be either positive or negative.b. ΨS is always greater than ΨP.
c. ΨP is always positive.
d. ΨP may be either positive or negative.
e. All of the listed responses are correct.
7. A cell has a pressure potential of 0 and a solute potential of -0.7 MPa. What is its water potential?
a. -0.7 MPab. -0.23 MPa
c. between 0 and -0.7 MPa
d. 0 MPa
e. +0.7 MPa
8. In a turgid cell, ______.
a. ΨS is always positiveb. Ψ = 0
c. Ψ = ΨS
d. ΨP < 0
e. ΨP is 0
9. Why does rapid movement of water molecules across the plasma membrane of a plant cell occur?
a. aquaporinsb. simple diffusion
c. transport proteins
d. All of the responses listed above are correct.
e. None of the listed responses is correct.
10. The cytoplasmic continuum connecting neighboring cells is called the ______.
a. apoplastb. Casparian strip
c. aquaporin
d. cell wall
e. symplast
11. The continuum of cell walls connecting neighboring cells is defined as the ______.
a. aquaporinb. apoplast
c. symplast
d. Casparian strip
e. plasmodesmata
12. Which of the cells below are involved with bulk flow?
a. tracheids, vessels, and plasmodesmatab. tracheids, vessels, and guard cells
c. tracheids, vessels, and sieve tubes
d. guard cells, vessels, and sieve tubes
e. tracheids, plasmodesmata, and sieve tubes
13. The last thing all water and solute molecules pass through before they enter the vascular system of roots and move upward to the leaves is ______.
a. a stomab. a root hair cell
c. an epidermal cell
d. an endodermal cell
e. a stele
14. A botanist discovered a mutant plant that is unable to produce the material that forms the Casparian strip. This plant is ______.
a. unable to transport water or solutes to the leavesb. unable to lose water by transpiration
c. unable to control the amounts of water and solutes it absorbs
d. unable to fix nitrogen
e. able to exert greater root pressure than normal plants
15. In a plant root, the one structure that water CANNOT move past via the apoplast is the ______.
a. cortexb. pericycle
c. epidermis
d. vascular tissues
e. endodermis
16. One of your friends has a terrarium on her windowsill containing various houseplants. She wonders why the glass is often fogged with water droplets. What would you tell her is the cause of the droplets?
a. adhesionb. photosynthesis
c. transpiration
d. root pressure
e. pressure flow
17. Root pressure is attributable to ______.
a. the high water potential of the vascular cylinder relative to the root cortexb. guttation
c. the pumping of minerals out of the vascular cylinder
d. transpiration
e. the accumulation of minerals in the vascular cylinder
18. Which of the following conditions will result in the fastest transport through the xylem in a tree, assuming adequate water supply in the roots?
a. negative pressure potential in the leaf mesophyllb. positive pressure potential in the mesophyll
c. phloem transport being in the opposite direction from the xylem transport
d. negative pressure potential in the guard cells
e. positive pressure potential in the xylem
19. What keeps the force of gravity from overcoming transpirational pull?
a. movement of water toward a sugar sinkb. upward pressure from the roots
c. high water pressure in the leaves
d. the Casparian strip blocking water molecules from moving out
e. cohesion and adhesion of water molecules
20. Normally, when an aphid feeds by puncturing plant tissues, it does not have to suck the sap out. If an aphid, however, inserted its feeding tube in the wrong place, the fluid in the aphid's guts could be sucked out through the feeding tube. What could explain this phenomenon?
a. The aphid punctured a stoma.b. The aphid punctured a sieve tube cell.
c. The aphid punctured xylem cells.
d. The aphid punctured a root nodule.
e. The aphid pierced the Casparian strip.
21. During winter, tree sap can sometimes freeze, and cavitation (the formation of an air pocket) may occur. Which of the following mechanisms of sap transport would you expect to be most immediately affected by cavitation?
a. pressure flow (mass flow)b. symplast function
c. transpiration
d. root pressure
e. active transport
22. What is the ultimate source of energy that moves water upward in the trunk of a tree?
a. evaporation of water by the sunb. breakdown and release of energy of sugar molecules
c. contraction of xylem cells
d. osmotic changes caused by alterations in salt content
e. pressure exerted by root cells
23. The rate of transpiration is expected to be greatest on a ______day.
a. windy and coolb. cool and dry
c. warm and moist
d. cool and moist
e. warm and dry
24. What process contributes directly to the turgor pressure that opens and closes stomata?
a. respirationb. guttation
c. active transport
d. transpiration
e. plasmolysis
25. Stomata open during the day in response to ______.
a. increased temperaturesb. blue light triggering the efflux of K+ from guard cells
c. the production of abscisic acid
d. blue light triggering the uptake of K+ by guard cells
e. increased CO2 levels
26. Which of the following describes how some plants are adapted to arid environments?
a. They can liberate carbon dioxide stored in intermediate molecules during the nightand fix it during the day even when stomata are closed.
b. They can leave their stomata open even on very hot, dry days.
c. They lose more water to transpiration than C3 plants.
d. They have evolved alternatives to the Calvin cycle.
e. All of the listed responses are correct.
27. In an apple tree that is producing sugars, sugar might flow from ______to ______.
a. a leaf ... a developing appleb. the trunk ... a leaf
c. a growing shoot tip ... the trunk
d. a developing apple ... a mature leaf
e. a growing shoot tip ... a leaf
28. Cells that are specialized for the transport of sugar between apoplast and symplast are ______cells.
a. companionb. bundle sheath
c. mesophyll
d. aquaporin
e. guard
29. When referring to phloem transport, what creates the "sink" in roots?
a. the absorption of water from the soil through epidermal cellsb. All of the listed responses are correct.
c. the active transport of sugars from phloem to cortex cells
d. the active transport of mineral ions into xylem cells
e. the osmosis of water into xylem cells
30. When sugar is transported in plants, what happens?
a. Leaves are always sugar sinks, and roots are always sugar sources.b. Leaves are always sugar sources, and roots are always sugar sinks.
c. Sugar always moves upward from roots to leaves.
d. Leaves may be sinks or sources, but roots are always sinks.
e. None of the listed responses is correct.
31. In order to be transported throughout a plant, viruses exploit ______.
a. the apoplastb. the Casparian strip
c. the ability of phloem to transmit electrical signals
d. the xylem's ability to transport minerals from roots to shoots
e. the ability of plasmodesmata to dilate to allow large particles to move between cells
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