Biology 102 Exam 2

A. Parenchyma B. Collenchyma C. Sclerenchyma D. Sieve-tube members E. Vessel elements 1) Cells with thick secondary walls used for support & protection; gives texture to certain fruits & nuts. 2) Living cells that lack nuclei; they transport sucrose and other organic nutrients. 3) The least specialized plant cells, which serve general metabolic, synthetic, and storage functions. 4) Cells with unevenly thickened primary walls that support stems and other young parts of the plant. 5) Mature cells without protoplasts (cell contents) but with thick secondary walls - transport water; pits present.

1. C 2. D 3. A 4. B 5. E

A. Abscisic acid B. Auxin C. Cytokinin D. Ethylene E. Gibberellin 43) Inhibits growth; closes stomata; stimulates dormancy. 44) Stimulates cell division by influencing the synthesis or activation of proteins required for mitosis. 45) Responsible for "Foolish Seedling Disease" in rice. 46) A gas that hastens fruit ripening. 47) Promotes internode (stem) elongation; promotes germination of certain seeds. 48) Growing a plant in space under conditions of microgravity is most likely to affect the activity of which hormone? 49) Which hormone has been shown to trigger a rapid plant response to a sudden decrease in humidity? 50) The Triple Response in seedlings is due to this hormone. 51) Agent Orange, used as a herbicide/defoliant, is a synthetic version of these hormones.

43. A 44. C 45. E 46. D 47. E 48. B 49. A 50. D 51. B

A = A is greater than B B = B is greater than A 52. A. The amount of macronutrients required by a plant. B. The amount of micronutrients required by a plant. 53. A. The amount of sucrose transported in the xylem. B. The amount of sucrose transported in the phloem. 54. A. The water potential in root hair cells. B. The water potential in the soil surrounding the root hairs. 55. A. The amount of water in a guard cell when the stoma is open. B. The amount of water in a guard cell when the stoma is closed. 56. A. The amount of water flowing in the symplast route through the endodermal cells in a root. B. The amount of water flowing in the apoplast route through the endodermal cells in a root. 57. A. The amount of auxin on the lighted side of a growing stem tip. B. The amount of auxin on the dark side of a growing stem tip. 58. A. The length of continuous darkness required for flowering by a short-day plant. B. The length of continuous darkness required for flowering by a long-day plant.

52. A 53. B 54. B 55. A 56. A 57. B 58. A

A = directly increases response B = directly decreases response C = no direct relationship Stimulus Response 59. Adding fertilizers to soil Water potential of soil 60. Abscisic acid Seed dormancy 61. Auxins Axillary bud growth 62. Gibberellins Cell division 63. High humidity day Translocation 64. Auxins Leaf drop (abscission) 65. Studying My grade in Biology 102

59. B 60. A 61. B 62. C 63. C 64. B 65. A

What soil horizon is the most fertile? A) A horizon B) B horizon C) C horizon D) D horizon E) E horizon

A) A horizon

You are part of a desert plant research team trying to discover crops that will be productive in desert climates around the world. You discover a plant that produces a guard cell hormone under low water (drought) conditions. Most likely the hormone is : A) Abscisic acid B) Gibberellic acid C) Ethylene D) Auxin E) Salicylic acid.

A) Abscisic acid

Land plants have all of the following tissue types except A) mesoderm. B) epidermal. C) meristematic. D) vascular. E) ground tissue.

A) mesoderm.

Imagine cutting a live twig from a tree and examining the cut surface of the twig with a magnifying glass. You locate the vascular tissue and observe a growing droplet of fluid flowing out from the cut surface. This fluid is probably A) phloem sap. B) xylem sap. C) guttation fluid. D) fluid of the transpiration stream. E) cell sap from the broken vacuoles of cells.

A) phloem sap.

Water and ions can move directly from plant cell to plant cell through: A) plasmodesmata. B) gap junctions. C) desmosomes. D) tight junctions. E) intercalated disks.

A) plasmodesmata.

What is the main cause of guttation in plants? A) root pressure B) transpiration C) pressure flow in phloem D) plant injury E) condensation of atmospheric water

A) root pressure

Additional phloem & xylem produced during secondary growth in a stem originate from which cells? A) vascular cambium B) apical meristem C) endodermis D) phloem E) xylem

A) vascular cambium

Your laboratory partner has an open beaker of pure water. By definition, the water potential of this water is A) zero B) a negative number. C) a positive number. D) equal to the atmospheric pressure. E). not meaningful, because it is an open beaker and not a plant tissue.

A) zero

As a youngster, you drive a nail in the trunk of a young tree that is 3 meters tall. The nail is about 1.5 meters from the ground. Fifteen years later, you return and discover the tree has grown to a height of 30 meters. The nail is now __________ meters above the ground. A) 0.5 B) 1.5 C) 3.0 D) 15.0 E) 28.5

B) 1.5

Primary growth in a plant is the responsibility of the _____. A) Lateral meristems B) Apical meristems C) Vascular cambium D) Cork cambium E) Xylem

B) Apical meristems

Which of the following is the most common naturally occurring auxin? A) Agent Orange B) Indoleacetic acid C) Gibberellin D) Adenine E) Zeatin

B) Indoleacetic acid

Most of the water and minerals taken up by a plant are absorbed by A) fruits. B) root hairs. C) the stem. D) stomata. E) leaves.

B) root hairs.

Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree? A) cool, dry day B) warm, dry day C) warm, humid day D) cool, humid day E) humid, windy day

B) warm, dry day

George Washington completely removed the bark from around the base of a cherry tree but was stopped by his father before cutting the tree down. George noticed that the leaves retained their normal appearance for several weeks, but that the tree eventually died. The tissue(s) that George left functional was (were) the A) phloem. B) xylem. C) cork cambium. D) cortex. E) companion and sieve cells.

B) xylem.

Arrange the following five events in an order that best explains the flow of materials in the phloem-translocation. 1. Water diffuses into the sieve elements. 2. Leaf cells produce sugar by photosynthesis. 3. Sugars are actively transported into sieve elements. 4. Sugar is transported from cell to cell in the leaf. 5. Sugar moves down the stem. A) 1, 2, 3, 4, 5 B) 2, 3, 4, 1, 5 C) 2, 4, 3, 1, 5 D) 4, 2, 1, 3, 5 E) 2, 4, 1, 3, 5

C) 2, 4, 3, 1, 5

Which of these conclusions is supported by the research of both Darwin and Went 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) Once shoot tips have been cut, normal growth cannot be induced. E) Light stimulates the synthesis of a plant hormone that responds to light.

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

Over-watering a plant will kill it. Why? A) Water does not have all the necessary minerals a plant needs to grow. B) Water neutralizes the pH of the soil. C) The roots cannot get air. D) Water will attract parasites. E) Water will form hydrogen bonds with the root of the cell wall.

C) The roots cannot get air.

Which of the following statements best explains why no tall trees seem to be CAM plants? A) Since the stomata are closed in the leaves, the Casparian strip is closed in the endodermis of the root. B) With stomata open at night, the transpiration rate would limit plant height. C) They would be unable to move water and minerals to the top of the plant during the day. D) They would be unable to supply enough sucrose for active transport of minerals into the roots during the day or night. E) Transpiration only occurs during the night, and this would cause a negative Ψ in the roots of a tall plant during the day.

C) They would be unable to move water and minerals to the top of the plant during the day.

Which one of the following statements about xylem is false: A) Xylem conducts material upward. B) Xylem conduction occurs within dead cells. C) Xylem transports mainly sugars and amino acids. D) Xylem has a lower water potential than the soil does. E) No energy input from the plant is required for xylem transport.

C) Xylem transports mainly sugars and amino acids.

If you were shipping bananas from South America to Chicago, which of the following chemicals would you want to eliminate from the plants' environment during shipping? A) CO2 B) cytokinins C) ethylene D) auxin E) gibberellic acids

C) ethylene

Most of the water within xylem vessels moves toward the top of a tree as a result of A) active transport of ions into the xylem. B) atmospheric pressure on roots. C) evaporation of water through stoma. D) the force of root pressure. E) osmosis in the root.

C) evaporation of water through stoma.

The best word to describe plant growth, in general, is A) perennial. B) weedy. C) indeterminate. D) derivative. E) primary.

C) indeterminate.

What is the symbiotic (mutualistic) association between roots and certain fungi? A) nitrogen fixation B) Rhizobium infection C) mycorrhizae D) parasitism E) root hair enhancement

C) mycorrhizae

What provides the most energy for water transport upward in the plant? A) ATP B) sucrose C) the sun D) proton gradients E) cohesion

C) the sun

"Wood" consists primarily of A) bark. B) periderm. C) xylem. D) phloem. E) cork.

C) xylem.

Which of the following is not part of the acid-growth hypothesis? A) Auxin stimulates proton pumps in cell membranes. B) Lowered pH results in the breakage of cross-links between cellulose fibrils in the wall. C) The cell wall fabric becomes looser (more plastic). D) Activated proton pumps stimulate cell division. E) The turgor pressure of the cell exceeds the restraining pressure of the loosened cell wall, and the cell takes up water and elongates.

D) Activated proton pumps stimulate cell division.

The bulk or majority of a plant's overall weight is due to: A) absorbed soil minerals. B) CO2. C) Carbohydrates. D) H2O. E) the uptake of organic nutrients from the soil.

D) H2O.

In plant roots, the Casparian strip is correctly described by which of the following? A) It is located in the walls between endodermal cells and cortex cells. B) It provides energy for the active transport of minerals into the stele from the cortex. C) It ensures that all minerals are absorbed from the soil in equal amounts. D) It ensures that all water and dissolved substances must pass through a cell before entering the vascular tissues. E) It provides increased surface area for the absorption of mineral nutrients.

D) It ensures that all water and dissolved substances must pass through a cell before entering the vascular tissues.

If certain plants (beans, for example) are infected with Rhizobium, what is the probable effect on the plant? A) It gets chlorosis. B) It dies. C) It dries up. D) It obtains additional nitrogen from nitrogen fixation. E) It contributes water to the soil.

D) It obtains additional nitrogen from nitrogen fixation.

Most crop plants get (from the soil) their nitrogen mainly in the form of A) NH4+ B) N2 C) C2H4 D) NO3- E) amino acids absorbed from the soil

D) NO3-

While responses to plant hormones are normally slow, which of the following hormones has been shown to be involved in the rapid closing of stomata? A) auxin B) cytokinin C) ethylene D) abscisic acid E) gibberellin

D) abscisic acid

Water flow in plants requires all of the following forces or interactions except A) adhesion of water molecules to cellulose. B) cohesion between water molecules. C) evaporation of water molecules from leaves. D) active transport through xylem cells. E) transport through tracheids & vessels.

D) active transport through xylem cells.

The experiments of van Helmont in the 1600's helped establish that the largest percentage of a plant's dry weight comes from A) water B) nitrogen in the air C) oxygen in the air D) carbon dioxide in the air E) minerals in the soil

D) carbon dioxide in the air

Phloem transport of sucrose can be described as going from "source to sink." Which of the following would not normally function as a sink? A) growing leaf B) growing root C) storage organ in summer D) mature leaf E) active meristems

D) mature leaf

Carnivorous plants have evolved mechanisms that trap and digest small animals. The products of this digestion are used mainly to supplement the plant's supply of : A) energy. B) carbohydrates. C) lipids and steroids. D) nitrogen. E) water.

D) nitrogen.

The N-P-K percentages on a package of fertilizer refer to the A) total protein content of the three major ingredients of the fertilizer. B) percentages of manure collected from 3 different types of animals. C) relative percentages of organic, inorganic, and synthetic nutrients in the fertilizer. D) percentages of three important mineral nutrients. E) proportions of three different nitrogen sources.

D) percentages of three important mineral nutrients.

During dry periods leaves wilt (dry up) and, coincidentally, photosynthesis slows down because A) wilted cells are incapable of photosynthesis. B) CO2 accumulates in the leaves and inhibits photosynthesis. C) there is insufficient water for the light-dependent reactions. D) stomata close, preventing CO2 entry into the leaf. E) the chlorophyll of flaccid cells cannot absorb light.

D) stomata close, preventing CO2 entry into the leaf.

Pores on the leaf surface that function in gas exchange are called A) guard cells. B) xylem cells. C) phloem cells. D) stomata. E) sclereids.

D) stomata.

A water molecule could move all the way through a plant from soil to root - to leaf - to air and pass through a living cell only once. This living cell would be a part of which structure? A) the Casparian strip B) a guard cell C) the root epidermis D) the endodermis E) the root cortex

D) the endodermis

Which of these statements about nitrogen fixation is incorrect? A) Atmospheric nitrogen is fixed (reduced) to ammonia (NH3) B) Fixed nitrogen is very often the limiting factor in plant growth. C) Nitrogen fixation is normally done by certain prokaryotes. D) Nitrogen fixers are sometimes symbiotic with legume (peas & beans) roots. E) Nitrogen fixation requires high temperatures and large amounts of energy.

E) Nitrogen fixation requires high temperatures and large amounts of energy.

All of the following cell types are correctly matched with their functions except A) tracheids - water transport. B) guard cell - regulation of transpiration. C) sieve-tube cell - translocation. D) vessel element - water transport. E) companion cell - formation of secondary xylem and phloem.

E) companion cell - formation of secondary xylem and phloem.

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) gravity. E) water potential.

E) water potential.