chapter11
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____
____
____
____
____
____
____
____
1. Plant transport systems ____.
a. move carbohydrates from photosynthetic organs to living cells
b. move water from the soil into the roots
c. move water from soil on up to leaves
d. transport minerals to meristematic regions
e. all of the above
2. Most of the water moving into a leaf is lost through ____.
a. osmotic gradients
b. transpiration
c. pressure flow forces
d. translocation
e. all of the above
3. Which of the following statements is false?
a. Transpiration creates a tension on water columns in a plant.
b. Transpiration is the loss of water from a plant in a gaseous form.
c. Water enters a root because of an osmotic gradient.
d. Most of the transpiration in a plant occurs through the cuticle.
e. Molecules of water exhibit cohesion resulting from hydrogen bonding of water molecules.
4. Which of the following is not a major force for moving water from place to place?
a. diffusion
b. osmosis
c. growth
d. capillary forces
e. gravity
5. Which of the following causes transpiration?
a. hydrogen bonding
b. the drying power of air
c. cohesion and adhesion of H2O molecules
d. water potential
e. all of the above
6. Water moves through a plant because of ____.
a. transpirational pull
b. the cohesion of water molecules
c. the strength of hydrogen bonds holding water molecules together
d. the replacement of lost water molecules
e. all of the above
7. Which of the following statements is not true?
a. Water vapor diffuses through stomata.
b. Flow from soil into roots reduces the amount of water in soil around roots.
c. Water vapor loss from leaf intercellular spaces lowers relative humidity of those spaces.
d. Large-diameter tracheids without pits have a much lower resistance to water flow than
small-diameter tracheids
e. Temperature can affect the rate of water movement.
8. Most of the water lost from a leaf comes most directly from ____.
____
9.
____ 10.
____ 11.
____ 12.
____ 13.
____ 14.
____ 15.
a. upper epidermal cells
b. lower epidermal cells
c. mesophyll cells
d. xylem tissue
e. phloem cells
The openings in leaves that function to exchange gases are called ____.
a. cuticles
b. stomata
c. guard cells
d. pits
e. pores
The cells that surround stomata are ____.
a. endodermal cells
b. guard cells
c. mesophyll cells
d. vascular bundle cells
e. vessel cells
Carbon dioxide enters the plant ____.
a. at night
b. when transpiration occurs
c. when stomata are closed
d. when potassium ions leave the guard cells
e. only during the day
Which statement is false?
a. The stomata open to allow carbon dioxide to enter the leaf, not as a result of
environmental conditions.
b. As carbon dioxide levels drop in guard cells, water will move in by osmosis.
c. When potassium ions enter guard cells, water will move in by osmosis.
d. At night, carbon dioxide builds up in guard cells, resulting in the movement of potassium
and water out of the guard cells.
e. When the guard cells collapse, the stomata are closed.
The stomata are closed ____.
a. during the day
b. when the guard cells are turgid
c. when the plant is well watered
d. during the time that plants are actively photosynthesizing
e. during the night
What would be the expected result if the transport of potassium into guard cells is inhibited?
a. Stomata would remain open.
b. Water would flow into the cells more freely.
c. Stomata would remain closed.
d. More carbon dioxide could enter.
e. both a and d
Usually, during the daytime ____.
a. carbon dioxide accumulates in leaf cells
b. turgor pressure in the guard cell decreases
c. water and potassium move into the guard cell
d. the guard cells close
e. water is conserved
____ 16. As long as the apoplast solution is more dilute than cytoplasm, ____.
a. water tends to flow back into the apoplast solution
b. water tends to flow into cells from the apoplast solution
c. reverse diffusion occurs
d. hydrostatic pressure lessens
e. there is no transport of water
____ 17. Which the statement about water is not true?
a. It serves as a substrate reactant for many biochemical reactions.
b. It provides strength and structure to herbaceous plants through turgor pressure.
c. Solutes cannot move without it.
d. Hydrogen bonding provides a broken network of H2O molecules.
e. Enzymes cannot acquire a 3-D shape without it.
____ 18. Which does not promote transpiration?
a. Potassium ions are pumped into guard cells.
b. Turgor pressure builds up in guard cells.
c. Photosynthesis occurs in guard cells.
d. Carbon dioxide enters the leaf.
e. A cuticle is present.
____ 19. Four of the five answers listed below are related by their participation in water movement through plants.
Select the exception.
a. hydrogen bonds
b. transpiration
c. cohesion of water molecules
d. xylem tension
e. photosynthesis
____ 20. A commercial fertilizer labeled 20-10-5 contains 20, 20, and 5% of which of the elements listed below?
a. potassium, nitrogen, phosphorus
b. nitrogen, phosphorus, potassium
c. nitrogen, calcium, potassium
d. carbon, hydrogen, oxygen
e. nitrogen, chlorine, potassium
____ 21. The nodules found on the roots of plants called legumes ____.
a. are abnormal growths
b. are house bacteria
c. are beneficial to the plant
d. a and b only
e. b and c only
____ 22. Nodules found on the roots of leguminous plants are involved in supplying which element for the plant?
a. aluminum
b. boron
c. magnesium
d. nitrogen
e. chlorine
____ 23. Water inside all of the xylem cells is being pulled upward primarily by ____.
a. turgor pressure
b. negative pressures (tensions)
c. osmotic gradients
d. pressure flow forces
e. active transport
____ 24. Which of the following is not true?
a. NO3- is the principal form of nitrogen in the atmosphere.
b. Plants cannot use nitrogen in the form of N2.
c. NH4+ is converted to NO3- by some soil bacteria in nitrification.
d. Plants must have nitrogen in the forms of NH4+ or NO3-.
e. Denitrification is the conversion of NO3- to N2.
____ 25. What would be the effect of the accidental seepage of a fungicide into soil surrounding a plant in a
mycorrhizal relationship?
a. The plant would die from lack of nutrients.
b. Water and mineral supply to the plant would slow.
c. The fungicide would cause the leaves to become chlorotic.
d. The plant would live just as it did before because the fungi are not necessary.
e. none of the above
____ 26. Mineral uptake depends on ____.
a. abscisic acid
b. adhesion
c. the concentration gradient
d. active transport
e. both c and d
____ 27. The ATP needed for active transport of minerals in the roots comes from ____.
a. respiration in the mitochondria of individual root cells
b. noncyclic photophosphorylation
c. cyclic photophosphorylation
d. the leaves where it is transported to the roots in the form of cellulose
e. respiration of the pith cells in the center of the root
____ 28. Which of the following statements does not apply to ion movement from root to shoot?
a. Ions move from stelar cells into the apoplast of the stele.
b. Ion concentrations are probably higher in shoots than in roots.
c. Ions secreted into the apoplast can be moved into and through the xylem.
d. Mechanisms are probably not selective and do not require ATP.
e. Growth requires mineral ions entering root cells.
____ 29. Mycorrhizae are ____.
a. roots
b. bacteria
c. fungus roots
d. isolated plants
e. small animals found in agricultural soils
____ 30. Of the following, which is not associated with root pressure?
a. accumulation of ions in the stele
b. lower water concentration in soil than in the xylem
c. soil saturated with water
d. water tends to enter the root and the stele
e. pressure builds in the xylem and forces xylem sap up the shoot
____ 31. Soils ____.
a. are part of the earth's crust
b. are changed by contact with the biotic part of the environment
c. are changed by contact with the abiotic part of the environment
d. are partly formed by elements dissolved from rock by acid rain
e. all of the above
____ 32. The most common form of sugar transported to the roots is ____.
a. glucose
b. fructose
c. sucrose
d. ribose
e. starch
____ 33. Movement of soluble organic material through plants is known as ____.
a. translocation
b. active transport
c. passive transport
d. transpiration
e. none of the above
____ 34. Large pressure gradients arise in sieve tube systems by means of ____.
a. vernalization
b. abscission
c. osmosis
d. transpiration
e. all of the above
____ 35. The role of companion cells in translocation is to ____.
a. assist vessel members with movement of organic substances
b. supply the potassium ions needed for water absorption
c. provide energy to the sieve tube members
d. help translocate substances
e. provide water
____ 36. The most commonly accepted theory used to explain movement of food through the phloem is ____.
a. cohesion-tension theory
b. the pressure flow hypothesis
c. active transport
d. dialysis
e. turgor pressure
____ 37. The movement of materials already in the phloem is described as ____.
a. source-to-sink
b. pressure flow
c. cohesion-tension
d. active transport
e. both a and b
____ 38. The source region in the pressure flow model of phloem transport is most often the ____.
a. root
b. flower
c. stem
d. leaf
e. soil
Essay
39. Explain the statement that transport of substances follows the direction from source to sink.
40. List the factors that affect flow of water in air, soil, and cells.
41. Provide a definition for osmosis.
42. Draw a diagram showing the flow of water through a plant.
43. Draw and label a diagram showing the pathways of water transport through the root.
44. Draw and label a diagram of the water flow in leaves.
45. Explain briefly the nitrogen cycle.
46. Explain how plants mobilize nutrients from the soil.
47. Describe the mechanism of mass flow in the phloem.
48. Which processes are involved in early formation of soil?