Deck 29: Plant Nutrition and Soils

Question 1

An example of cation exchange is ______ replacing ______ on a clay particle.

A)H⁺; K⁺
B)H⁺; NO₃⁻
C)NO₃⁻; SO₄²⁻
D)OH⁻; SO₄²⁻
E)HCO₃⁻; Mg²⁺

Answer 1

A

Question 2

Which of the following is NOT an essential element?

A)molybdenum
B)copper
C)iron
D)aluminum
E)chlorine

Answer 2

D

Question 3

Which of the following ions is MOST likely to be precipitated in alkaline soils?

A)hydroxide
B)bicarbonate
C)sulfate
D)iron
E)potassium

Answer 3

D

Question 4

Which of the following is NOT a phloem-mobile element?

A)nitrogen
B)magnesium
C)phosphorus
D)potassium
E)iron

Question 5

Which of the following statements concerning beneficial elements is FALSE?

A)Silicon is a beneficial element only for horsetails.
B)Sodium is a beneficial element for certain halophytes.
C)They are essential for most plants.
D)Aluminum is a beneficial element for the tea plant.
E)They are essential for plants grown only under specific environmental conditions.

Question 6

A micronutrient is a plant nutrient required in concentrations equal to or less than ______ mg per kg of dry matter.

A)1
B)10
C)100
D)1000
E)10,000

Question 7

The chief reservoir of nitrogen is:

A)the soil.
B)the ocean.
C)living organisms.
D)dead organic material.
E)the atmosphere.

Question 8

Field capacity is the:

A)total amount of water present in a one-hectare field after a soaking rain.
B)percentage of water that a soil can hold against the action of gravity.
C)percentage of water remaining in a soil when plants undergo irreversible wilting.
D)total amount of fertilizer required for maximal plant growth in a one-hectare field.
E)total amount of mineral nutrients present in a one-hectare field after a soaking rain.

Question 9

Which of the following soils can hold the greatest amount of water against the action of gravity?

A)silt
B)loam
C)coarse sand
D)fine sand
E)clay

Question 10

Chlorosis refers to the:

A)localized death of tissues.
B)yellowing of leaves.
C)stunted growth of stems and leaves.
D)development of tumors.
E)healing of wounds.

Question 11

As dead organic materials are broken down by bacteria and fungi, the nitrogen not used by these organisms is released as ______ in a process called ______.

A)NH₄⁺; ammonification
B)NO₃⁻; nitrification
C)NO₂⁻; nitrification
D)N₂; denitrification
E)N₂O; denitrification

Question 12

Plants using Strategy II will utilize which of the following for iron mobilization and uptake?

A)a Fe²⁺ transporter
B)pores in the plasma membrane
C)the reduction of Fe³⁺ to Fe²⁺
D)proton pumps that acidify the rhizosphere
E)Fe³⁺-phytosiderophores

Question 13

Which of the following statements about nutrient cycles is FALSE?

A)They are also called biogeochemical cycles.
B)All nutrients recycled to the soil are available for plant use.
C)Some cycles involve the atmosphere.
D)Each element has a different cycle.
E)Macronutrients and micronutrients are recycled.

Question 14

Legumes grown in culture benefit from the addition of cobalt because the cobalt:

A)inhibits the growth of pathogenic bacteria.
B)stimulates cell division of the apical meristem.
C)stimulates the growth of root cells.
D)is required by mycorrhizae.
E)is required by symbiotic nitrogen-fixing bacteria.

Question 15

Humus consists mostly of:

A)living organic matter.
B)dead organic matter.
C)sand.
D)silt.
E)clay.

Question 16

The permanent wilting percentage is the percentage of:

A)colloidal particles remaining in the soil after a heavy rain.
B)colloidal particles that would cause irreversible wilting.
C)colloidal particles that would cause reversible wilting.
D)water remaining in a soil when irreversible wilting occurs.
E)water remaining in a soil when reversible wilting occurs.

Question 17

Which of the following statements about soil is FALSE?

A)The A horizon has the greatest physical, chemical, and biological activity.
B)The A horizon is the topsoil.
C)The B horizon is a region of deposition.
D)The B horizon is the subsoil.
E)The C horizon is part of the true soil.

Question 18

Which of the following statements concerning iron is FALSE?

A)Iron in the soil is usually insoluble and thus unavailable to plants.
B)Iron ranks fourth in abundance among all elements on the surface of the Earth.
C)All plants use Strategy I for iron mobilization and uptake.
D)Phytosiderophores are iron-chelating compounds.
E)Iron in the soil is normally present in the oxidized (Fe³⁺) form.

Question 19

In magnesium-deficient plants, older leaves become more severely chlorotic than younger leaves because:

A)magnesium is less phloem-mobile than chlorophyll.
B)magnesium is more phloem-mobile than chlorophyll.
C)younger leaves withdraw magnesium from older leaves.
D)older leaves withdraw magnesium from younger leaves.
E)magnesium is more mobile in younger leaves than in older leaves.

Question 20

Which of the following is NOT a micronutrient?

A)zinc
B)copper
C)manganese
D)calcium
E)nickel

Question 21

A symbiosome consists of:

A)bacterioids only.
B)bacterioids and the surrounding host membrane only.
C)bacteriods, host membrane, and curled root hair only.
D)bacteriods, host membrane, and nodule primordium only.
E)bacteriods, host membrane, cortical cells, and vascular tissues only.

Question 22

Which of the following statements about leghemoglobin is FALSE?

A)It acts as an O₂ carrier.
B)It buffers the O₂ concentration in nodules.
C)It is found in the cytosol of the bacteroid.
D)Its heme portion is produced by the bacteroid.
E)Its globin portion is produced by the plant.

Question 23

Which of the following statements about nitrogenase is FALSE?

A)It is an enzyme involved in nitrogen fixation.
B)It requires O₂ as a cofactor.
C)It appears to be similar in all organisms.
D)It contains molybdenum as one of its prosthetic groups.
E)It uses ATP as an energy source.

Question 24

Nitrite is oxidized to nitrate by:

A)Nitrosomonas.
B)Nitrobacter.
C)ammonifying bacteria and fungi.
D)denitrifying bacteria.
E)plant roots.

Question 25

A determinate nodule is different from an indeterminate nodule in that a determinate nodule:

A)is elongated.
B)is cylindrical.
C)is spherical
D)has a persistent meristem.
E)consists of several zones.

Question 26

The direct role of flavonoids in nodule formation is to:

A)stimulate formation of infection threads.
B)stimulate cell wall degradation.
C)stimulate root-hair curling.
D)attract rhizobia.
E)activate the plant Nod genes.

Question 27

Rhizobia enter legumes by invading the:

A)seeds.
B)root hairs.
C)stems.
D)leaves.
E)flowers.

Question 28

Which of the following is NOT a way in which the phosphorus cycle differs from the nitrogen cycle?

A)The phosphorus cycle has more steps.
B)The phosphorus cycle is not dependent on specific groups of microorganisms.
C)In the phosphorus cycle, the Earth's crust is the primary reservoir of the element.
D)The phosphorus cycle does not involve a gaseous stage.
E)The phosphorus cycle involves the long-term weathering of rocks.

Question 29

Which of the following is NOT a way in which nitrogen is lost from an ecosystem?

A)harvesting of plants
B)soil erosion
C)burning of plants
D)leaching
E)nitrification

Question 30

Which of the following is(are) a product of denitrification?

A)NH₄⁺
B)NO₃⁻
C)NO₂⁻
D)N₂
E)Amino acids

Question 31

The ______ symbiosis is an example of a nitrogen-fixing symbiosis that continues throughout the life cycle of the host.

A)legume-Rhizobium
B)legume-Bradyrhizobium
C)Azolla-Anabaena
D)Alnus-actinomycete
E)Ceanothus-actinomycete

Question 32

Which of the following is NOT a strategy utilized by plants for the uptake of phosphate from the soil?

A)rapid root growth
B)rapid lateral root growth
C)proliferation of root hairs
D)inhibition of extraradical hyphae
E)symbioses with arbuscular mycorrhizal fungi

Question 33

In the process of nitrogen fixation, ______ is converted to ______.

A)NH₄⁺; NO₃⁻
B)NO₃⁻; NO₂⁻
C)N₂; NO₂⁻
D)N₂; NO₃⁻
E)N₂; NH₄⁺

Question 34

In most herbaceous plants grown in nitrate-rich soil, the glutamine synthetase-glutamate synthase pathway occurs in:

A)leaf vacuoles.
B)leaf mitochondria.
C)leaf chloroplasts.
D)root mitochondria.
E)root plastids.

Question 35

______ is the principal source of nitrogen available to crop plants.

A)Organic nitrogen
B)Nitrate
C)Ammonium
D)Glutamine
E)Glutamate

Question 36

In soils where nitrogen is limiting, _____ is a major and direct source of nitrogen.

A)nitrate
B)ammonia
C)organic nitrogen
D)nitrite
E)N₂

Question 37

The role of Nod factors is to:

A)stimulate the formation of infection threads.
B)stimulate root-hair curling.
C)activate the plant Nod genes.
D)activate the bacterial Nod genes.
E)activate the plant genes for nodule formation.

Question 38

______ is one of the ways in which phosphorus is lost from terrestrial ecosystems.

A)Leaching
B)Evaporation
C)Burning
D)Recycling
E)The action of microorganisms

Question 39

Which of the following statements concerning cluster roots is FALSE?

A)They are portions of lateral roots.
B)They are bottlebrush-like.
C)They release phosphatases and protons.
D)They release large amounts of malate and citrate.
E)They are long-lasting.

Question 40

Which of the following groups contains species that are nonsymbiotic, photosynthetic, nitrogen-fixing bacteria?

A)genus Azotobacter
B)genus Azotococcus
C)genus Beijerinckia
D)genus Clostridium
E)cyanobacteria

Question 41

Strategy I for iron mobilization and uptake involves the acidification of the rhizosphere by proton pumps.

Question 42

Lime is added to soils in order to:

A)provide nutrients.
B)raise the pH.
C)remove excess salts.
D)provide ions for cation exchange.
E)kill insect pests.

Question 43

Bacteria that induce nodule formation in clover will also induce nodule formation in soybeans.

Question 44

A determinate nodule has a persistent meristem.

Question 45

Wilted plants in a soil at its permanent wilting percentage will not recover even when placed in a humid chamber.

Question 46

A single root hair may contain several infection threads.

Question 47

Plants can synthesize all their required amino acids and vitamins.

Question 48

In the process of ammonification, ammonium ions are used to form amino acids.

Question 49

Nitrosomonas is the bacterium that is primarily responsible for oxidizing ammonia to nitrite.

Question 50

Nickel is an essential element for plant growth.

Question 51

Loam soils, the best agricultural soils, contain sand, silt, and clay particles.

Question 52

Which of the following statements about hyperaccumulators is FALSE?

A)They are plants that are harmed by high concentrations of potentially toxic materials.
B)They may concentrate trace elements, radionucleides, and/or heavy metals.
C)They are being used in phytoremediation.
D)They may concentrate toxins to produce toxic foliage.
E)They include alpine penny cress and Arabidopsis halleri.

Question 53

If a bag of fertilizer is labeled 5-10-6, then you know that the fertilizer contains:

A)5% potassium.
B)10% nitrogen.
C)6% phosphorus.
D)5% nitrogen.
E)10% potassium.

Question 54

The C horizon of soil is also called the subsoil.

Question 55

Deficiency symptoms of phloem-immobile elements such as potassium and nitrogen appear first in older leaves.

Question 56

The most common nitrogen-fixing bacteria are Rhizobium and Bradyrhizobium.

Question 57

A beneficial element is one that is essential for limited groups of plants.

Question 58

Clay particles have an excess of surface negative charges, and humus has an excess of positive charges.

Question 59

______ is the most common metal in soils and causes problems where the soil is acidic.

A)Lead
B)Cadmium
C)Zinc
D)Cobalt
E)Aluminum
True-False Questions

Question 60

The destruction of marshes and wetlands most notably affects the ______ stage of the nitrogen cycle.

A)ammonification
B)denitrification
C)nitrogen fixation
D)nitrification
E)assimilation

Question 61

Some nitrogen-fixing symbioses involve plants other than legumes.

Question 62

Leghemoglobin acts as an oxygen carrier.

Question 63

Cluster roots are usually found in plants that usually form mycorrhizae.

Question 64

In most soils, most of the phosphorus is present in forms that are not available to the plant.

Question 65

A bag of fertilizer labeled 20:10:5 contains 20% phosphorus.

Question 66

Extraradical hyphae extend beyond the phosphorus-depletion zone of the root.

Question 67

Exudative bursts are characteristic of cluster roots.

Question 68

Parasitic angiosperms such as mistletoe directly break down proteins in organic matter found in the soil.

Question 69

In desert ecosystems, nitrogen loss from the soil by leaching is negligible.

Question 70

Synthetase ok? It was "synthatase", but I figured that was wrong.