Which of the following is a correct statement about sugar movement in phloem?

Exam

Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Which of the following elements is incorrectly paired with its function in a plant?

A) nitrogen_component of nucleic acids, proteins, coenzymes

B) magnesium_component of chlorophyll; activates many enzymes

C) phosphorus_component of nucleic acids, phospholipids, ATP, several coenzymes

D) potassium_; osmosis; operation of stomata

E) sulfur_component of DNA; activates some enzymes

2) In the nutrition of a plant, which element is classified as a macronutrient?

A) zinc B) chlorine C) calcium D) molybdenum E) manganese

9) The amount and direction of movement of water in plants can always be predicted by measuring

A) air pressure.

B) rainfall.

C) proton gradients.

D) dissolved solutes.

E) water potential (ψw).

11) If �ψp= 0.3 MPa and ψs= -0.45 MPa, the resulting ψwis

A) +0.75 MPa.

B) -0.75 MPa.

C) -0.15 MPa.

D) +0.15 MPa.

E) impossible to calculate with this information.

12) All of the following statements about xylem are correct except:

A) Xylem conducts material upward.

B) Xylem conduction occurs within dead cells.

C) transport is a function of pressure flow.

D) Xylem usually has a lower water potential than the soil does.

E) No energy input from the plant is required for xylem transport.

13) All of the following describe an important transport mechanism in plants except

A) cohesion-tension-transpiration.

B) osmosis.

C) photorespiration.

D) active transport.

E) bulk flow from source to sink.

14) Water entering the stele of the root from the cortex must pass through the

A) Casparian strip.

B) phloem.

C) endodermal cytoplasm.

D) epidermis.

E) xylem.

15) Which of the following factors that sometimes play a role in the rise of sap in the xylem depends on the

expenditure of energy by the plant?

A) secretion of ions into the stele of the root

B) cohesion of water molecules due to hydrogen bonding

C) transpiration of water from the leaves

D) adhesion of water to xylem tracheids and vessels

E) diffusion of water into the root hairs

18) Water potential is generally most negative in which of the following parts of a plant?

A) mesophyll cells of the leaf

B) xylem vessels in leaves

C) xylem vessels in roots

D) cells of the root cortex

E) root hairs

20) Transpiration in plants requires all of the following except

A) transport through pits

B) cohesion between water molecules.

C) evaporation of water molecules.

D) root pressure

E) transport through tracheids.

22) Guard cells do which of the following?

A) protect the endodermis

B) accumulate K+ ions and close the stomates

C) contain chloroplasts that import K+ ions directly into the cells

D) guard against mineral loss through the stomates

E) help balance CO2 uptake vs. H2O loss.

25) If the guard cells and surrounding epidermal cells in a plant are deficient in potassium ions, all of the

following would occur except

A) photosynthesis would decrease.

B) roots would take up less water.

C) phloem transport rates would decrease.

D) leaf temperatures would decrease.

E) stomata would be closed.

27) Which of the following is a correct statement about sugar movement in phloem?

A) Diffusion can account for the observed rates of transport.

B) Movement can occur both upward and downward in the plant.

C) Sugar is translocated from sinks to sources.

D) Only phloem cells with nuclei can perform sugar movement.

E) Sugar transport does not require energy.

29) According to the pressure-flow hypothesis of phloem transport,

A) solute moves from a high concentration in the "source" to a lower concentration in the "sink."

B) water is actively transported into the "source" region of the phloem to create the turgor pressure needed.

C) the combination of a high turgor pressure in the "source" and transpiration water loss from the "sink"

moves solutes through phloem conduits.

D) the formation of starch from sugar in the "sink" increases the osmotic concentration.

E) the pressure in the phloem of a root is normally greater than the pressure in the phloem of a leaf.

31) In the pressure-flow hypothesis of translocation, what causes the pressure?

A) root pressure

B) the osmotic uptake of water by sieve tubes at the source

C) the accumulation of minerals and water by the stele in the root

D) the osmotic uptake of water by the sieve tubes of the sink

E) hydrostatic pressure in xylem vessels

32) All of the following may function in signal transduction in plants except

A) calcium ions.

B) P-protein

C) receptor proteins.

D) protein kinases

E) second messengers.

33) Which of these conclusions is supported by the research of both Went and the Darwins on shoot responses to

light?

A) When shoots are exposed to light, a chemical substance migrates toward the light.

B) Agar contains a chemical substance that mimics a plant hormone.

C) A chemical substance involved in shoot bending is produced in shoot tips.

D) Growth is slowed down on the side of the shoot away from the light.

E) Light stimulates the synthesis of a plant hormone that responds to light.

35) Which of the following is the only known naturally occurring auxin?

A) 2, 4-D B) IAA C)GA D) ABA E) TCA

36) Why is it so difficult to study the actions of plant hormones?

A) They often interact to produce an effect.

B) They are found in small quantities in the plant.

C) We probably have not discovered all of them.

D) They sometimes cause different responses in different plants.

E) All of the above make the study of plant hormones difficult.

37) According to the acid growth hypothesis, auxin works by

A) dissolving sieve plates, permitting more rapid transport of nutrients.

B) dissolving the cell membranes temporarily, permitting cells that were on the verge of dividing to divide

more rapidly.

C) changing the pH within the cell, which would permit the electron transport chain to operate more

efficiently.

D) allowing the affected cell walls to stretch.

E) greatly increasing the rate of deposition of cell wall material.

38) Which of the following hormones would be most useful in causing the rooting of plant cuttings?

A) oligosaccharins

B) abscisic acid

C) cytokinins

D) gibberellins

E) auxins

39) Which plant hormone(s) is (are) most closely associated with cell division?

A) ethylene

B) cytokinin

C) abscisic acid

D) phytochrome

E) brassinosteroids

41) The application of which of the following hormones would be a logical first choice in an attempt to produce

normal growth in mutant dwarf plants?

A) indoleacetic acid

B) cytokinin

C) gibberellin

D) abscisic acid

E) ethylene

42) One effect of gibberellins is to stimulate cereal seeds to produce

A) RuBP carboxylase.

B) lipids.

C) abscisic acid.

D) starch.

E) amylase.

43) While responses to plant hormones are normally slow, which of the following hormones has been shown to be

involved in the rapid opening and closing of stomata?

A) auxin B) cytokinin C) ethylene D) abscisic acid E) gibberellin

44) If you were shipping green bananas to a supermarket in Boston, which of the following chemicals would you

want to eliminate from the plants' environment?

A) CO2

B) cytokinins

C) ethylene

D) auxin

E) gibberellic acids

45) Auxin is responsible for many plant growth responses, including all of the following except

A) phototropism.

B) formation of adventitious roots.

C) apical dominance.

D) promotion of abscission.

E) cell elongation.

Photoperiodism; p. 632 �������������������������������������������������������������������������������������������������������� ans: c

Which of the following statements about Pr and Pfr is FALSE?

a.���� They are photoreceptors.

b.���� They participate in photoconversion reactions.

c.���� Pr is the biologically active form.

d.���� Pr absorbs 660-nanometer light.

e.���� Pfr absorbs 730-nanometer light.

Photoperiodism; p. 632 �������������������������������������������������������������������������������������������������������� ans: e

A high level of ______ in the middle of the dark period will inhibit flowering in ______ plants that otherwise would have flowered.

a.���� Pr; long-day

b.���� Pr; short-day

c.���� Pfr; day-neutral

d.���� Pfr; long-day

e.���� Pfr; short-day

The Tropisms; p. 623 ����������������������������������������������������������������������������������������������������������� ans: d

______ light is the most effective in producing a phototropic response.

a.���� Green

b.���� Yellow

c.���� Orange

d.���� Blue

e.���� Red

The Tropisms; p. 623������������������������������������������������������������������������������������������������ ans: b

In plants oriented horizontally, auxin moves toward the ______ surface of shoots and toward the ______ surface of roots before bending occurs.

a.���� upper; upper

b.���� lower; lower

c.���� upper; lower

d.���� lower; upper

e.         cortical; epidermal

The Tropisms; p. 624������������������������������������������������������������������������������������������������ ans: e

In roots, statoliths are localized in the:

a.���� epidermal cells.

b.���� vascular tissues.

c.���� cells surrounding the vascular tissues.

d.���� epidermis of the rootcap.

e.���� columella.

Circadian Rhythms; pp. 627�628������������������������������������������������������������������������������������������ ans: d

Which of the following statements about circadian rhythms is FALSE?

a.���� They are endogenous.

b.���� They can be entrained by light-dark cycles.

c.���� They can be entrained by temperature cycles.

d.���� They speed up as the temperature rises.

e.         �They enable the plant to measure changing daylength

The Tropisms; pp. 626�627 ������������������������������������������������������������������������������������� ans: d

Which of the following statements about thigmotropism is FALSE?

a.���� It enables roots to navigate around rocks.

b.���� It is a response to contact with a solid object.

������ c.���� An example is the climbing of tendrils.

d.���� Cells touching the support lengthen more than cells on the other side.

������ e.���� The stems of peas can store the memory of tactile stimulation.

Dormancy; p. 637������������������������������������������������������������������������������������������������������������������ ans: d

A dormant seed will germinate only when:

a.���� the temperature becomes milder.

b.���� water becomes available.

c.���� oxygen becomes available.

d.���� precise environmental cues are received.

e.� �� water and oxygen become available at the same time

.

Ans.� c

Answer Key

Testname: SAMPLE TEST 2.TST

1) Answer: E

2) Answer: C

9) Answer: E

11) Answer: C

12) Answer: C

13) Answer: C

14) Answer: C

15) Answer: A

18) Answer: A

20) Answer: D

22) Answer: E

25) Answer: D

27) Answer: B

29) Answer: A

31) Answer: B

32) Answer: B

33) Answer: C

35) Answer: B

36) Answer: E

37) Answer: D

38) Answer: E

39) Answer: B

41) Answer: C

42) Answer: E

43) Answer: D

44) Answer: C

45) Answer: D

What is a correct statement about sugar movement in phloem?

Which one of the following statements about phloem transport is correct?

Which description of movement in phloem is correct?

What is the direction of flow of sugars in phloem?