Exam 4

During nitrification, urea is first broken down into A. 2NH4+ (ammonium) B. 2NO3- (nitrate) C. 2NH3 (ammonia) D. 2NO (nitrous oxide)

C. 2NH3 (ammonia)

Auxin is transported toward the ______ in stems, and toward the ______ in roots. A. base; base B. tip; tip C. base; tip D. None of the above.

C. base; tip

Which of the following plant hormones is a gas? A. cytokinins B. gibberellins C. ethylene D. auxin

C. ethylene

Herbicides, such as 2,4_D, 2,4,5-T, and agent orange are derivatives of A. absisic acid. B. gibberellins. C. cytokinins. D. auxins.

D. auxins.

A hormone used to ripen fruit after they have been picked is A. gibberellin. B. cytokinin. C. abscisic acid. D. ethylene.

D. ethylene.

Which of the following is NOT an essential element? A. potassium B. zinc C. boron D. lead

D. lead

The hormone that maintains apical dominance is A. auxin. B. gibberellin. C. abscisic acid. D. cytokinin.

A. auxin.

Which of the following are NOT colloids in the plant cell? A. clay B. cellulose C. amylose D. All the above are colloids in the plant cell.

A. clay

Which of the following plants flower independently of the duration of light? A. day neutral plants B. long day plants C. short day plants D. None of the above.

A. day neutral plants

Experiments on cocklebur have shown that the ______ perceives the photoperiod. A. leaf blade B. stem C. apical meristem D. petiole

A. leaf blade

If a short-day plant receives a one-minute exposure to light in the middle of the dark period rather than continuous darkness, it will: A. not flower. B. produce smaller flowers. C. produce more flowers. D. produce larger flowers.

A. not flower.

The regulation of transpiration A. occurs by turgor changes in the guard cells. B. is due to the action of the casparian strips. C. is dependant on the available moisture in the soil. D. happens by hydathodes.

A. occurs by turgor changes in the guard cells.

A response to touch is referred to as A. thigmotropism. B. gravitropism. C. phototropism. D. touchtropism.

A. thigmotropism.

Vavilov postulated that there were ____ from which our cultivated plants originated A. 7 centers B. 8 centers C. 9 centers D. 10 centers

B. 8 centers

Which of the following statements about xylem and phloem is FALSE? A. They are closely associated functionally. B. Xylem transports only water and phloem transports only nutrients. C. They form a continuous vascular system. D. They are closely associated spatially.

B. Xylem transports only water and phloem transports only nutrients.

The hormone that can induce dormancy in seeds is A. cytokinin. B. abscisic acid. C. ethylene D. auxin.

B. abscisic acid.

Field capacity refers to A. all the gravitational water the soil can hold. B. all the capillary water the soil can hold. C. all the hygroscopic water the soil can hold. D. None of the above.

B. all the capillary water the soil can hold.

The gravitropic response is thought to be due to A. chromoplasts. B. amyloplasts. C. phragmoplasts. D. chloroplasts.

B. amyloplasts.

Which of the following avenues of water is affected by casparian strips A. None the above are affected by casparian strips B. apoplastic movement C. trans-cellular movement D. symplastic movement

B. apoplastic movement

All plant hormones: A. act in the tissues where they are produced. B. communicate information. C. are stimulatory. D. are active in large quantities.

B. communicate information.

The plant hormone that promotes cell division is A. gibberellin B. cytokinin. C. auxin D. abscisic acid

B. cytokinin.

Which of the following is NOT sensed by the root cap? A. gravitropism B. heliotropism. C. hydrotropism D. All the above are sensed by the root cap.

B. heliotropism.

Water physically bound to soil particles is A. gravitational water. B. hygroscopic water. C. capillary water. D. available water.

B. hygroscopic water.

The nitrogenase system is used during A. ammonification. B. nitrogen fixation. C. nitrification. D. denitrification.

B. nitrogen fixation.

If a coleoptile tip is covered with a blackened glass tube then illuminated from the side, the coleoptile will: A. die. B. not bend. C. bend toward the light. D. bend away from the light.

B. not bend.

Which of the following hormones inhibits plant growth? A. cytokinins B. gibberellin C. absisic acid D. auxin

C. absisic acid

When water moving through the cortex via the apoplastic pathway reaches the endodermis: A. it enters the cell walls. B. the symplastic pathway is blocked. C. apoplastic movement is stopped by the Casparian strips. D. it continues through the apoplast.

C. apoplastic movement is stopped by the Casparian strips.

The water in the soil that is used by plants is the A. available water. B. bounded water. C. capillary water D. None of the above.

C. capillary water

The person who published Origin of Cultivated Plants in 1822 was A. Vavilov. B. Linnaeus C. de Candolle. D. Bortnick

C. de Candolle.

Which of the following indicates the correct sequence of tissues through which water moves from the soil into the root? A. root hairs, vascular cylinder, endodermis, cortex B. root hairs, endodermis, cortex, vascular cylinder C. epidermis, cortex, endodermis, vascular cylinder D. endodermis, epidermis, vascular cylinder, cortex

C. epidermis, cortex, endodermis, vascular cylinder

Scientist who exam traditional herbal medicines are referred to A. herbalists. B. quacks. C. ethnobotanists. D. medicinbotanists.

C. ethnobotanists.

Auxin is transported through: A. vessels only. B. sieve tubes only. C. phloem parenchyma cells. D. None of the above.

C. phloem parenchyma cells.

Cytokinins are synthesized in ____ and transported from there to all other parts of the plant. A. Fruits B. leaves C. roots D. stems

C. roots

The B horizon in soils is commonly called the A. top soil. B. bedrock. C. subsoil D. parent material.

C. subsoil

The chief reservoir of nitrogen is: A. living organisms. B. dead organic material. C. the atmosphere. D. the soil.

C. the atmosphere.

What is responsible for keeping a plant's circadian rhythm in step with the natural day-night cycle? A. phototropism B. auxin C. the environment D. an endogenous timing mechanism

C. the environment

The major difference between the symplastic and the transcellular pathways of the root is that the transcellular pathway involves: A. cell walls. B. protoplasts. C. vacuoles. D. plasmodesmata.

C. vacuoles.

The first all mineralized strata of soil is the A. A horizon B. B horizon C. C horizon D. D horizon

B. B horizon

Which of the following statements about phototropism is INCORRECT? A. Phototropism is a response to touch. B. Shoots exhibit a negative phototropic response. C. Roots exhibit a positive phototropic response. D. All the above are incorrect.

D. All the above are incorrect.

Which of the following is NOT a way for plants to get carbon? A. CO2 B. photosynthesis C. preformed organic molecules. D. All the above are mwans that plants get carbon.

D. All the above are mwans that plants get carbon.

Which of the following is true of the cohesion-tension theory? A. Water leaving mesophyll cells near stomates have lower water potentials. B. Cells near the above ones have higher water potentials. C. Water moves from cells with a high water potential to cells with lower potentials. D. All the above are true.

D. All the above are true.

According to Vavilov, which of the following was the most important center for cultivated plants? A. Indo-Malayan center B. Central Asiatic center C. Abyssinian center D. Chinese center

D. Chinese center

Which of the following statements about the floral stimulus is FALSE? A. It is transmitted from leaf to bud. B. It has been called florigen. C. Both A & B. D. Neither A or B

D. Neither A or B

Which of the following is a correct statement about the origin of cultivated plants? A. Plants exhibit dominant genes at the periphery of their populations. B. Cultivated plants are similar to their wild progenitors. C. Plants exhibit recessive genes in the center of their populations. D. None of the above are correct.

D. None of the above are correct.

The loss of water through the stomates is referred to as A. transferation. B. transcription. C. transmogrification. D. None of the above.

D. None of the above.

The cohesion-tension theory relies heavily upon the properties of water. Which of the following statements is correct about water? A. Water is held together by non-polar covalent bonds. B. Due to these bonds, water has low cohesion. C. Because of the low cohesion, water can move up through wide tubes. D. Water can attract charged molecules.

D. Water can attract charged molecules.

In nyctinastic movements, leaves: A. have their stomata open during the night and closed during the day. B. twine around a support such as a fence post. C. are rolled during the day and unrolled at night. D. are oriented vertically in darkness and horizontally in light.

D. are oriented vertically in darkness and horizontally in light.

When tobacco callus cells are treated with equal concentrations of auxin and cytokinin, ______ is(are) formed. A. roots B. leaves C. buds D. more callus cells

D. more callus cells

Phloem loading is when A. water raises via root pressure. B. water passes into vessel member by active transport. C. sugar is passed to a sink. D. sugar passes into sieve cells via active transport.

D. sugar passes into sieve cells via active transport.

The pressure-flow hypothesis explains A. the movement of solutes in a plant. B. the field capacity of water. C. the movement of water in a plant. D. the movement of carbohydrates in a plant.

D. the movement of carbohydrates in a plant.