Deck 35: Plant Nutrition

Question 1

A common consequence of nutrient deficiencies in plants is chlorosis, which is ____.

A) wilting due to a lack of chlorine in leaves
B) death of the growing tips
C) premature loss of leaves
D) bursting of cells from excess water uptake due to an inability to clear chlorine from them
E) yellowing of plant tissues due to a lack of chlorophyll

Answer 1

E

Question 2

Which element is considered an essential micronutrient for plants?

A) gold
B) carbon
C) uranium
D) nitrogen
E) copper

Answer 2

E

Question 3

Soil mineral particles that range from 0.2-0.02 mm in diameter are called ____.

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

Answer 3

A

Question 4

Which element is considered an essential macronutrient for plants?

A) oxygen
B) boron
C) lithium
D) silicon
E) molybdenum

Question 5

Which element is considered an essential micronutrient for plants?

A) zinc
B) potassium
C) hydrogen
D) arsenic
E) platinum

Question 6

You might infer from packages of commercial fertilizer that which nutrients are most limiting to plant growth?

A) carbon, nitrogen, and phosphorous
B) nitrogen, phosphorous, and potassium
C) hydrogen, phosphorus, and magnesium
D) iron, magnesium, and nitrogen
E) phosphorus, potassium, and calcium

Question 7

Hydroponic culture is the process of ____.

A) growing plants in pure water mixed with carefully measured amounts of specific minerals
B) irrigation of dry areas to improve mineral absorption by plants
C) growing plants in ponds and lakes to improve their access to water, allowing the plants to place more resources into the shoot system
D) irrigation of dry areas to prevent crop plants from wilting
E) growing plants with specific hydrocarbons added to the soil to test the effect on plant growth

Question 8

Which element is not considered an essential micronutrient for plants in general, but is required by horsetails and perhaps some grasses such as wheat?

A) gold
B) boron
C) silicon
D) zinc
E) magnesium

Question 9

Plants are able to generate all of the substances they need for their metabolism using energy from the ____.

A) soil
B) air
C) root
D) Sun
E) rain

Question 10

What element is considered an essential macronutrient for plants?

A) zinc
B) uranium
C) iron
D) nickel
E) carbon

Question 11

Plant tissues are more than 90% ____ by weight.

A) carbohydrates
B) water
C) carbon
D) nitrogen
E) cellulose

Question 12

Leaf chlorosis is not likely to be caused by a deficiency in ____.

A) nitrogen
B) magnesium
C) iron
D) zinc
E) boron

Question 13

Experiments have shown that even if it is supplied by no other means, plants near the ocean can get enough of the essential micronutrient ____ from the air, and plants can also get this essential micronutrient from sweat from a person's hands.

A) sulfur
B) manganese
C) chlorine
D) magnesium
E) sodium

Question 14

Which characteristic is not true for an essential element?

A) It may play only one role in plant metabolism.
B) It is necessary for normal growth and reproduction.
C) It may be contained in plant seeds in high enough quantities to sustain the adult plant.
D) Occasionally, it can be functionally replaced by another element.
E) It may be required in only trace amounts.

Question 15

Which element is considered an essential micronutrient for plants?

A) calcium
B) lithium
C) sulfur
D) nickel
E) oxygen

Question 16

Soil particles composed of decomposing organic matter are called ____.

A) sand
B) humus
C) silt
D) clay
E) mineral

Question 17

The nutrients that a plant needs for normal growth and development are acquired through the ____.

A) Sun
B) rain
C) leaves
D) roots
E) bark

Question 18

What macronutrient is rarely deficient?

A) carbon
B) hydrogen
C) oxygen
D) zinc
E) carbon dioxide

Question 19

What element is considered an essential macronutrient for plants?

A) gold
B) manganese
C) chromium
D) nitrogen
E) copper

Question 20

Which element is considered an essential micronutrient for plants?

A) phosphorus
B) silver
C) molybdenum
D) carbon
E) lead

Question 21

The ____ horizon is usually light in color and contains little organic matter.

A) A
B) B
C) C
D) D
E) O

Question 22

The ____ horizon extends to the underlying bedrock, and consists of mineral particles and rock fragments but generally no organic material?

A) A
B) B
C) C
D) D
E) O

Question 23

Scientists are attempting to genetically modify rice so that it will not incorporate ____ into the grains.

A) arsenic
B) methylmercury
C) chelated iron
D) lead
E) uranium hexafluoride

Question 24

Soil mineral particles that range from 0.02-0.002 mm in diameter are called ____.

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

Question 25

The surfaces of clay particles in soil ____.

A) often bear positively charged ions
B) release water to plants easily
C) often bear negatively charged ions
D) are generally hydrophobic
E) acidify the soil

Question 26

The soils in which most plants do best are ____.

A) mixtures of mainly sand and silt
B) sandy soils
C) soils made mostly of humus
D) clay soils
E) loams

Question 27

Research in Colorado's San Juan Mountains has illustrated that in comparison to stands of lodgepole pine and Englemann spruce, stands of trembling aspen are not likely to ____.

A) grow in warmer soil
B) grow in soil with higher nitrate concentrations
C) be associated with different arrays of soil-dwelling organisms
D) allow more sunlight to reach the soil surface
E) retain their leaves through the winter

Question 28

A soil with roughly equal amounts of humus, silt, clay, and sand is called a ____.

A) topsoil
B) loam
C) subsoil
D) compost
E) oversoil

Question 29

A soil that is mostly ____ will tend to dry quickly compared to other soil types.

A) sand
B) humus
C) clay
D) silt
E) organic matter

Question 30

Most plants would grow best in a soil with ____.

A) very small air spaces
B) relatively large air spaces
C) air spaces filled almost entirely with water
D) various sizes of air spaces
E) no air spaces

Question 31

Mycorrhizae, present for most plant species, generally do not help roots with the uptake of ____.

A) water
B) nitrogen
C) phosphate
D) carbon
E) sugars

Question 32

Areas that receive heavy rainfall tend to have ____ soils, and arid regions tend to have ____ soils.

A) acidic; alkaline
B) pH-neutral; acidic
C) alkaline; acid
D) acidic; pH-neutral
E) pH-neutral; alkaline

Question 33

Phytoremediation is ____.

A) rotating crops so that soil minerals are replenished
B) replacing eroded topsoil so that plants can grow in the soil again
C) plowing under all or parts of crops to improve the soil
D) the use of plants to remove pollutants from the environment
E) replacing unwanted plants with plants useful to humans

Question 34

Which substance is not released by plant roots to enable and improve access to particular nutrients in the soil?

A) amino acids
B) carbohydrates
C) enzymes
D) fatty acids
E) carbon dioxide

Question 35

The ____ horizon tends to accumulate mineral ions but relatively little organic matter, and is generally penetrated by mature tree roots?

A) A
B) B
C) C
D) D
E) O

Question 36

What soil component is most important for retaining water in soil for use by plants?

A) sand
B) humus
C) clay
D) silt
E) rock

Question 37

The ____ horizon is the most fertile soil layer, where the roots of most herbaceous plants are located?

A) A
B) B
C) C
D) D
E) O

Question 38

Mycorrhizae are ____.

A) intertwined roots of different species of plants
B) connecting points between branching roots
C) symbiotic associations between a fungus and plant roots
D) specialized root hairs
E) localized swellings in plant roots filled with nitrogen-fixing bacteria

Question 39

Roots obtain cations through cation exchange, where soil particles absorb ____ provided directly or indirectly by the root, and thus release cations.

A) Cl^-
B) K⁺
C) H⁺
D) water
E) CO₂

Question 40

Soil mineral particles that are less than 0.002 mm in diameter are called ____.

A) sand
B) humus
C) clay
D) silt
E) microparticles

Question 41

Animals trapped and digested by "carnivorous" plants such as the cobra lily are used primarily as ____.

A) an energy supplement during winter months
B) a carbon source for the plant
C) a nutrient supplement in nutrient-deficient environments
D) food for bacteria and fungi that grow symbiotically with the plant roots
E) an energy supplement for small plants growing in shady areas

Question 42

Haustorial roots of dodders and other nonphotosynthetic, parasitic plants rob the host plant of ____.

A) sugars only
B) minerals only
C) water only
D) sugars and minerals only
E) sugars, minerals, and water

Question 43

Root nodules are ____.

A) intertwined roots of different species of plants
B) connecting points between branching roots
C) symbiotic associations between a fungus and plant roots
D) specialized root hairs
E) localized swellings in plant roots filled with nitrogen-fixing bacteria

Question 44

Which of the following is mostly performed by bacteria living within the roots of plants in the legume family?

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

Question 45

Studies of a soybean plant ( Glycine max ) and the bacterium Bradyrhizobium japonicum have shown that after the bacterium enters the root, cells of the root cortex begin to divide in response to ____.

A) a flavonoid released by soybean roots
B) nod gene products produced by soybean roots
C) nod gene products produced by the bacterium
D) nitrogen fixation by the bacterium
E) a flavonoid produced by the bacterium

Question 46

Bacteroids are ____.

A) specialized nitrifying bacteria
B) small buds from ammonifying bacteria
C) specialized bacteria that help some plant roots absorb phosphorus
D) enlarged and immobilized nitrogen-fixing bacteria
E) interactions between plant root hairs and bacteria

Question 47

Studies of a soybean plant ( Glycine max ) and the bacterium Bradyrhizobium japonicum have shown that the tip of a root hair curls toward the bacterium in response to ____.

A) a flavonoid released by soybean roots
B) nod gene products produced by soybean roots
C) nod gene products produced by the bacterium
D) nitrogen fixation by the bacterium
E) a flavonoid produced by the bacterium

Question 48

The process of producing NH₄⁺from decaying organic material is called ____.

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

Question 49

Species of Rhizobium and Bradyrhizobium bacteria are most directly associated with ____.

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

Question 50

In the process of nitrogen assimilation, ____ is converted to ____, which is then rapidly used to synthesize organic molecules.

A) NH₄⁺; NO₃^-
B) N₂; NO₃^-
C) NO₃^-; NH₄⁺
D) NH₃; NH₄⁺
E) NO₃^-; N₂

Question 51

The most common limit to plant growth is a lack of ____.

A) phosphorous
B) carbon
C) hydrogen
D) oxygen
E) nitrogen

Question 52

Plants can generally absorb and make use of nitrogen in the form of ____.

A) NO₃^-only
B) both NO₃^-and NH₄⁺
C) NH₄⁺only
D) N₂only
E) both N₂and NH₄⁺

Question 53

Most plants absorb nitrogen in the form of ____.

A) NH₄⁺
B) CN
C) N₂
D) NH₃
E) NO₃^-

Question 54

The process in which NH₄⁺is oxidized to NO₃^-is called ____.

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

Question 55

A mutant soybean plant that is unable to produce leghemoglobin will most likely suffer from ____ deficiency.

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

Question 56

Leghemoglobin, which contains an iron-containing heme group, is used to ____.

A) remove O₂from roots
B) produce H₂O from O₂
C) limit O₂entry into the nodule
D) transport O₂in the xylem
E) produce O₂from H₂O

Question 57

If nitrifying bacteria were not present in a soil, plants would ____.

A) take up nitrogen for their use mainly as NH₄⁺
B) not survive because they could not get useful nitrogen
C) take up nitrogen for their use mainly as N₂
D) take up nitrogen for their use mainly as NH₃
E) take up nitrogen for their use mainly as NO₃^-

Question 58

The process of adding hydrogen to N₂, creating NH₃and eventually NH₄⁺, and which requires a substantial input of ATP, is called ____.

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

Question 59

The enzyme nitrogenase is irreversibly inhibited by low concentrations of ____.

A) O₂
B) NO₃^-
C) N₂
D) CO₂
E) NH₄⁺

Question 60

The enzyme nitrogenase is most directly involved in the process called ____.

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

Question 61

What deficiency symptom is common among plants with inadequate levels of nitrogen, magnesium, iron, zinc, or copper? What characteristics would be seen in the plants' leaves?

Question 62

Plants having the ability to take up organic nitrogen are most likely to be found in the ____.

A) arctic tundra
B) salt marsh
C) tropical forest
D) grassland
E) temperate forest

Question 63

Legumes grown in sterile soil would be expected to have ____.

A) purplish veins
B) chlorosis and mottled or bronzed leaves
C) chlorosis in older leaves and stunted growth
D) burned leaf edges and curled, mottled, or spotted older leaves
E) pale green, rolled, or cupped leaves

Question 64

Nutrients clearly limit the growth of plants. Explain four ways that plants have adapted to increase access to nutrients and what limits the association from becoming more common.

Question 65

Imagine that you are a farmer who chose not to rotate your crops with soybeans even though the local extension agent recommended that you do so. Which deficiency symptom in your crops should indicate to you that the extension agent's advice was correct?

A) chlorosis and mottled or bronzed leaves
B) burned leaf edges and curled, mottled, or spotted older leaves
C) purplish veins
D) pale green, rolled, or cupped leaves
E) chlorosis in older leaves and stunted growth

Question 66

The ____ both parasitizes other plants and performs photosynthesis.

A) snow plant
B) lady-of-the-night orchid
C) mistletoe
D) cobra lily
E) dodder

Question 67

Harrison and van Buuren used ____ to reveal the molecular basis of how mycorrhizae transport phosphate.

A) proteins
B) mRNA
C) cDNA
D) cRNA
E) viruses

Question 68

Epiphytes are ____.

A) plants that are not parasites but that do grow on other plants instead of the soil
B) plants that trap animals and digest them
C) parasitic plants that use mycorrhizae to obtain nutrients and food indirectly from other plants
D) plants that deal with nutrient-deficient soil by growing a large, netlike mesh of roots through several layers of the soil
E) parasitic plants that use haustoria to obtain nutrients and food directly from other plants

Question 69

Inadequate drainage can lead to a buildup of excess salts in the soil.

Question 70

Plants usually grow best in sandy soils.

Question 71

Why might a soil that has a sufficient concentration of a mineral element-for example, calcium-not have sufficient availability of the element to maximize plant growth rates?

Question 72

Carbon is rarely deficient in plants.

Question 73

Farmers often grow legumes such as soybeans every few years and plow much of the plant parts into the soil. This practice serves mainly to replenish the soil with useful forms of ____.

A) carbon
B) nitrogen
C) phosphorus
D) oxygen
E) manganese

Question 74

What is the potential significance of root exudates?

Question 75

A square meter of fertile soil contains trillions of bacteria.

Question 76

Why are hydroponics used in mineral nutrition experiments examining essential elements?

Question 77

The A horizon contains little, if any, organic matter.

Question 78

Harrison and van Buuren identified a phosphate transport protein in Glomus , which is a ____.

A) carnivorous plant
B) bacterium that parasitizes plants
C) mycorrhizal fungus
D) bacteroid
E) parasitic plant

Question 79

Chlorosis is a condition that results in yellowed plant tissues.

Question 80

The size of soil particles is one of the major factors that determine how much water is available to plants.