Deck 32: Plant Nutrition and Transport

Question 1

Commercial inorganic fertilizers have greatly increased agricultural productivity.Which of the following is an advantage of using inorganic rather than organic fertilizers?

A)Inorganic fertilizers increase the water- holding capacity of the soil.
B)Nutrients are released faster from inorganic fertilizers.
C)It is easier for plants to absorb nutrients in an inorganic form.
D)Inorganic nutrients bind more tightly to soil particles.

Answer 1

B

Question 2

According to this figure,which of the following can directly use atmospheric N2?

A)ammonifying bacteria
B)plant roots
C)nitrogen- fixing bacteria
D)nitrifying bacteria

Answer 2

C

Question 3

A fertilizer with which of the following nitrogen- phosphorous- potassium ratios would most likely solve the problem of yellowed leaves and stunted growth?

A)0:20:20
B)0:20:0
C)0:0:20
D)20:0:0

Answer 3

D

Question 4

Which of the following are important in breaking down organic material in fertile topsoil?

A)abrasive granite particles
B)bacteria and fungi
C)humus and cations
D)plant roots

Question 5

Under which of the following weather conditions would transpiration be most rapid?

A)windy,wet weather
B)hot,humid weather
C)cold,humid weather
D)hot,dry weather

Question 6

Which of the following options correctly lists the sequence of structures through which water passes into a root?

A)guard cell,endodermis,cortex,xylem
B)epidermis,cortex,endodermis,xylem
C)root hair,xylem,endodermis,phloem
D)root hair,cortex,xylem,endodermis

Question 7

Which of the following would be the best way to determine whether aphids must actively draw phloem sap into their digestive tract or if hydrostatic pressure in the phloem tube could force the sap into them?

A)Cut a phloem tube from a plant and see if an aphid can still take up sap from it.
B)Insert mouth parts removed from an aphid,without including the digestive tract,and see if phloem sap keeps flowing through them.
C)Cut a phloem tube off an aphid and see if it can still feed.
D)Measure relative rates of sugar manufacture in leaves with and without aphids.

Question 8

Most plants can absorb and use which of the following forms of nitrogen directly?

A)nitrate and ammonium
B)nitrate only
C)ammonium and nitrogen gas
D)nitrite and nitrate

Question 9

How do mineral ions get into the xylem cells of a plant root by way of the intracellular route?

A)They are taken up by root hair cells and transferred from cell to cell via plasmodesmata.
B)They percolate between root cells to the xylem and then enter a xylem vessel.
C)They are actively taken in to the xylem of root hairs.
D)They move in solution through cell walls of the endodermis.

Question 10

The pores that facilitate gas exchange in plant leaves are called

A)plasmodesmata.
B)guard cells.
C)lenticels.
D)stomata.

Question 11

The two main forces that move water through a plant are

A)root pressure and photosynthesis.
B)transpiration and root pressure.
C)transpiration and pressure flow.
D)active transport and cohesion.

Question 12

increase the surface area of roots.

A)Root hairs
B)Casparian strips
C)Plasmodesmata
D)Cell walls and endoplasmic reticulum

Question 13

Which of the following is most likely to be an epiphyte?

A)a plant that captures insects
B)a plant that parasitizes another plant
C)a plant with a very deep root system
D)a plant growing on the branches of another plant

Question 14

Which of the following is a potential problem with the use of transgenic varieties of plants that contain Bt toxin?

A)Transgenic crop varieties with Bt toxin are not very hardy and require a lot of care.
B)Transgenic crop varieties with Bt toxin require large amounts of fertilizers and chemical insecticides to grow.
C)Bt toxin may be harmful to some beneficial insects.
D)Bt toxin may be harmful to humans.

Question 15

Generally speaking,fluids in plants are

A)pulled through both xylem and phloem.
B)actively pumped throughout the plant.
C)pushed through phloem and pulled through xylem.
D)pushed through xylem and pulled through phloem.

Question 16

"Smart" plants can reduce overuse of fertilizers by

A)binding specifically to certain fertilizers before they are needed and storing them in their root systems.
B)informing the grower of a nutrient deficiency before damage occurs.
C)slowing the process of minerals washing out of the soils.
D)using photosynthesis and fungal relationships to generate their own fertilizer.

Question 17

A hot,dry summer will reduce crop yields in part because

A)carbon dioxide uptake is reduced by the stomata closing to prevent excessive water loss.
B)oxygen uptake is reduced by the stomata closing to prevent excessive water loss.
C)the stomata of the plants stay open to help cool the leaves.
D)carbon dioxide release is reduced by the stomata closing to prevent excessive water loss.

Question 18

What force is responsible for the cohesiveness of water?

A)osmosis
B)ionic bonding
C)negative pressure created by evaporation
D)hydrogen bonding between water molecules

Question 19

In the water relations of vascular plants,the cohesive property of water is most important in the

A)epidermis.
B)stomata.
C)xylem.
D)internal air spaces.

Question 20

How do sugars move from one sieve- tube cell to the next?

A)by flowing along with water through perforations in the sieve plate
B)by active transport across cell membranes at the sieve plate
C)by diffusion through a companion cell that spans the sieve plate
D)by osmotic diffusion through the sieve plate

Question 21

Much research is being done to increase the nitrogen- fixing ability of plants with root nodules.Why is this an important goal for agricultural researchers?

A)By removing the bacteria from the root nodules,more fixed nitrogen will be available to the plants.
B)Nitrogen is an essential component of the amino acids used to form protein.
C)Increasing the nitrogen- fixing ability of plants will allow them to make better use of nitrogen fertilizers.
D)Decreasing the size of nodules will allow plants to fix more nitrogen into their own molecules.

Question 22

The loss of water from the leaves of plants is

A)adhesion.
B)osmosis.
C)cohesion.
D)transpiration.

Question 23

Legumes,such as beans or peas,

A)form mutualistic associations with nitrogen- fixing bacteria.
B)fix N2 from the atmosphere in their leaves.
C)form parasitic relationships with other photosynthetic plants.
D)form mycorrhizal associations to increase nitrogen fixation in the soil.

Question 24

If a plant is kept in the dark,

A)the stomata will remain closed the entire time that the plant is in the dark.
B)the stomata will remain open the entire time that the plant is in the dark.
C)the guard cells will open as water is added.
D)the stomata continue their daily rhythm of opening and closing.

Question 25

Why don't the countries that most need high- protein crops raise them?

A)High- protein crops are typically low in most other vital nutrients.
B)High- protein crops require extensive irrigation,which may not be affordable to these countries.
C)High- protein crops usually require fertilizers,which may not be affordable to these countries.
D)High- protein crops are more difficult to process,making the foods they produce too expensive.

Question 26

Which of the following would be most likely to cause stomata to open?

A)Water molecules entering the stomatal pore.
B)Sunrise on a clear morning.
C)A cool night is setting in.
D)Hot,dry weather,and strong winds.

Question 27

The relationship between a plant and mycorrhizal fungi is best described as

A)commensal.
B)parasitic.
C)mutualistic.
D)competitive.

Question 28

If you examine the soil profile revealed by a fresh road cut through a grassy rise,which of the following features will you probably find in the B horizon?

A)an abundance of worms and burrowing insects
B)a predominance of slightly weathered rock and gravel
C)an abundance of decomposing organic material
D)an abundance of fine clay but not much organic material

Question 29

The sugar "sink" in roots is the result of

A)active transport of mineral ions into xylem cells.
B)absorption of water from the soil through epidermal cells.
C)pull of gravity on sugar molecules.
D)active transport of sugars from phloem to root cells.

Question 30

On a trip to the Southwest,you and a friend collect some seeds from a piñon,which is a type of pine tree.Your friend also gathers a small bagful of soil from under the piñon tree.Back home,both of you plant your seeds in commercial sterilized potting soil,but your friend adds a spoonful of the collected dirt to each of her pots.Her seedlings do better than yours.Which of the following is the likeliest reason?

A)The soil from the Southwest probably contained fungi able to establish a mycorrhizal association with the seedlings' roots.
B)The soil from the Southwest probably contained macronutrients missing from the potting mix.
C)Pine seedlings are better adapted to the sandy soil of the Southwest than to commercial potting mix.
D)The soil from the Southwest probably contained nitrogen- fixing bacteria that colonized the seedlings' root nodules.

Question 31

Carnivorous plants are more likely to grow in acid bogs because

A)organic matter decays so slowly there.
B)mycorrhizal growth is inhibited.
C)acid rain damages leaves and stems.
D)acid soil inhibits growth of plant roots.

Question 32

The existence of a hydrostatic pressure gradient in phloem tubes can be accounted for by

A)the diffusion of water from one sieve- tube cell to the next.
B)the active transport of water from sugar sources to sugar sinks.
C)the fact that the leaves are higher than the roots,which means that gravity creates pressure.
D)the loading of sugars into phloem at sources and removal of sugars at sinks.

Question 33

Nitrogen fixation consists of

A)the conversion of ammonia to nitrate.
B)the conversion of N2 to ammonia or nitrate.
C)the production of ammonium from decomposing organic matter.
D)the conversion of N2 to ammonia.

Question 34

What are the macronutrients present in most commercial fertilizers?

A)N,C,and K
B)N,P,and K
C)C,H,and N
D)C,N,and P

Question 35

Where do plants get most of their mass?

A)from carbon dioxide in the atmosphere
B)from nitrogen in the atmosphere
C)from water,as van Helmont predicted
D)from organic molecules taken up from the soil

Question 36

Carnivorousness in plants is primarily an adaptation for

A)discouraging herbivorous insects.
B)growing in soil poor in organic material.
C)obtaining supplemental carbon for photosynthesis.
D)growing in soil poor in usable nitrogen.

Question 37

What is true of the guard cells shown in the right- hand panel of this figure?

A)Water is entering these cells.
B)Their turgor pressure is increasing.
C)These cells are hypertonic to their immediate surrounding.
D)These cells are hypotonic to their immediate surrounding.

Question 38

In an attempt to find out where a growing plant gets its mass,van Helmont planted a willow seedling in a pot of soil.After five years,the willow weighed 76.8 kg,and the soil had lost 0.06 kg of weight.Only water had been added to the pot.Which of the following conclusions should van Helmont have drawn?

A)Plants get their mass from water and atmospheric CO2.
B)Plants get all or almost all of their mass from a source other than soil.
C)Plants get their mass from water and air.
D)Plants get their mass from water.

Question 39

Legumes are frequently grown in rotation with primary field crops.What is the benefit in this?

A)A greater amount of the primary crop can be harvested each year.
B)Legumes decrease the amount of organic material in the soil.
C)Nitrogen is added to the soil because of the legumes' symbiotic nitrogen- fixing bacteria.
D)Soil erosion is reduced by frequent plowing.

Question 40

Why has drip irrigation been developed?

A)Drip irrigation uses less water than traditional methods.
B)Drip irrigation increases soil salinity.
C)Drip irrigation increases soil erosion.
D)Drip irrigation increases evaporation and drainage.

Question 41

What is the physical barrier in the root that regulates the flow of water to xylem via cell walls?

A)Casparian strip
B)epidermis
C)cortex
D)phloem

Question 42

Compared to conventional agriculture,organic farming

A)uses fewer synthetic pesticides.
B)increases crop yields.
C)requires much less hands- on work.
D)guarantees the safety and extra health benefits of food.

Question 43

Which of the following options lists the set of plant macronutrients that make up about 98% of a plant's dry weight?

A)nitrogen,potassium,manganese,sulfur,copper,and phosphorus
B)carbon,nitrogen,potassium,manganese,sulfur,and phosphorus
C)carbon,oxygen,hydrogen,potassium,zinc,and copper
D)carbon,oxygen,hydrogen,nitrogen,sulfur,and phosphorus

Question 44

An example of an organism that parasitizes a host plant is

A)a mycorrhizal fungus.
B)a Venus flytrap.
C)nitrogen- fixing bacteria in root nodules.
D)mistletoe.

Question 45

What is the role of the fungus in a mycorrhizal association?

A)secretion of growth factors
B)absorption of water,phosphate,and other minerals
C)contributes to photosynthesis
D)release of water

Question 46

Which of the following essential macronutrient for plants is obtained directly from the air?

A)magnesium
B)hydrogen
C)carbon
D)nitrogen

Question 47

Which of the following essential nutrients is most likely to leach from the soil?

A)Mg2+
B)K+
C)NO3-
D)Ca2+

Question 48

Which of the following options best describes the mechanism that causes a stoma to open?

A)K+ enters the guard cells and water follows passively,making the cells turgid.
B)K+ leaves the guard cells and water follows passively,making the cells flaccid.
C)K+ activates water pumps in the guard cell membrane that make them turgid.
D)Loss of K+ from guard cells creates positive pressure and expands the guard cells.

Question 49

Micronutrients function in plants mainly as

A)regulators of membrane transport.
B)cofactors in chemical reactions.
C)joining elements in organic molecule carbon skeletons.
D)food reserves for pollen grains.

Question 50

What is implied by this figure?

A)The clay particle has a positive charge at its surface.
B)The root hair has a negative charge at its surface.
C)The plant does not need K+.
D)The clay particle has a negative charge at its surface.