Deck 6: Plant Adaptations to the Environment

Question 1

Once dissolved in water,the CO₂ molecule reacts with water to form ________.

Answer 1

bicarbonate

Question 2

A plant growing in the shade is expected to have a ________ maximum photosynthetic rate than a plant growing in sunlight.

Answer 2

lower

Question 3

The measure used to describe the free energy of water at any point along the soil-plant-atmosphere continuum is called its ________ potential.

Answer 3

water

Question 4

C₄ plants divide photosynthesis between two types of cells: the mesophyll and the ________ cells.

Question 5

The ratio of surface area to weight for a leaf is called the ________.

Question 6

The process of photosynthesis in plants occurs in specialized cells within the leaf called ________ cells.

Question 7

In tropical regions with distinct wet and dry seasons,plants that drop their leaves at the onset of the dry season are termed drought ________.

Question 8

________ are openings in the leaves of terrestrial plants that allow for the uptake of CO₂.

Question 9

In some shade plants,the negative effect of high light levels on the rate of photosynthesis is referred to as ________.

Question 10

The transfer of heat from the plant to the surrounding environment is influenced by the existence of the ________ layer.

Question 11

The stage of photosynthesis during which chlorophyll absorbs light energy is called the ________ reaction.

Question 12

The enzyme that catalyzes carboxylation during photosynthesis is called ________.

Question 13

To survive,grow,and reproduce,plants must maintain a ________ carbon balance.

Question 14

The force exerted outward on a plant cell wall by the water contained in the cell is called ________ pressure.

Question 15

________ is the transfer of heat energy between a solid and a moving fluid.

Question 16

The ratio of carbon fixed (photosynthesis)per unit of water lost (transpiration)is called the ________ efficiency.

Question 17

Plants convert bicarbonate to carbon dioxide using the enzyme carbonic ________.

Question 18

The light level at which the rate of carbon uptake in photosynthesis equals the rate of carbon loss in respiration is the light ________ point.

Question 19

All life is made up of complex molecules built on a framework of ________ atoms.

Question 20

________ is the movement of a substance from areas of higher to lower concentration.

Question 21

Which of the following conditions is required for the continued movement of water from the soil into and through a plant via transpiration?

A)ψatm < ψroot < ψleaf < ψsoil
B)ψatm < ψleaf < ψroot < ψsoil
C)ψsoil < ψroot < ψleaf < ψatm
D)ψsoil < ψatm < ψroot < ψleaf

Question 22

In photosynthesis,the net uptake of CO₂ by a plant is greatest

A)when PAR equals zero.
B)at the light compensation point.
C)during photoinhibition.
D)at the light saturation point.

Question 23

The process of using energy from the Sun to convert CO₂ into organic molecules is called

A)respiration.
B)assimilation.
C)photosynthesis.
D)chemosynthesis.

Question 24

Organisms that derive their energy from sunlight are referred to as

A)homotrophs.
B)heterotrophs.
C)chemoautotrophs.
D)photoautotrophs.

Question 25

In photosynthesis,the uptake of CO₂ by plants occurs through openings on the surface of

A)roots.
B)stems.
C)leaves.
D)flowers.

Question 26

The ability of some plants to tolerate extreme cold is known as ________.

Question 27

The ultimate source of carbon from which life is constructed is derived from

A)atmospheric carbon dioxide.
B)respiration.
C)decomposition.
D)the consumption of other organisms.

Question 28

The pigment that absorbs light energy (photons)in photosynthesis is

A)rubisco.
B)chlorophyll.
C)PEP.
D)CAM.

Question 29

Unlike terrestrial plants,submerged aquatic plants lack

A)leaves.
B)chlorophyll.
C)stomata.
D)stems.

Question 30

Nutrients that are needed by plants in large amounts are called ________.

Question 31

The value of photosynthetically active radiation above which no further increase in photosynthesis occurs is referred to as

A)photoinhibition.
B)chlorophyll compensation.
C)the light compensation point.
D)the light saturation point.

Question 32

Many plants adapted to arid environments use the ________ photosynthetic pathway to fix CO₂ during the night.

Question 33

The osmotic potential of a plant refers to the

A)force exerted outward on a cell wall by the water contained in the cell.
B)surfaces of larger molecules,such as those in the cell walls,exerting an attractive force on water.
C)association between concentrations of solutes in cells and the rate of water loss.
D)ratio of carbon fixed (photosynthesis)per unit of water lost (transpiration).

Question 34

The higher rates of diffusion and photosynthesis under elevated atmospheric concentrations of CO₂ have been termed the ________.

Question 35

Much of the nitrogen taken in by a plant is used to synthesize the molecules rubisco and ________.

Question 36

Overall,water movement from the soil,through plant tissues,and finally to the atmosphere through transpiration,is driven by a gradient of

A)water potential.
B)osmotic pressure.
C)water temperature.
D)specific leaf area.

Question 37

Submerged aquatic plants can take up CO₂ from the water in all of the following ways,except

A)diffusion through stomata.
B)direct diffusion of ambient CO₂ from water across cell membranes.
C)active transport of bicarbonate into the leaf followed by conversion to CO₂.
D)excretion of carbonic anhydrase into the water,followed by uptake of the resulting CO₂.

Question 38

In the Calvin-Benson or C₃ photosynthetic pathway,the enzyme rubisco catalyzes the reaction called

A)chemosynthesis.
B)carboxylation.
C)photoreduction.
D)respiration.

Question 39

A CO₂ gradient between the inside and outside of a leaf is maintained during photosynthesis because

A)energy is expended by the plant to maintain the CO₂ gradient.
B)the CO₂ concentration outside of the leaf is always increasing.
C)the CO₂ concentration in the mesophyll is constantly decreasing.
D)the stomata close whenever more CO₂ is needed.

Question 40

Net photosynthesis is equal to

A)photosynthesis + respiration.
B)photosynthesis - respiration.
C)photosynthesis x respiration.
D)photosynthesis / respiration.

Question 41

Which of the following is an incorrect statement?

A)A large leaf maximizes light interception.
B)A deeply lobed leaf minimizes heat exchange with the atmosphere.
C)A thick leaf reduces loss of water via transpiration.
D)A leaf with a high SLA is generally thin and flexible.

Question 42

As temperatures continue to rise,the photosynthetic rate reaches a maximum related to

A)the temperature response of rubisco.
B)the thickness of the boundary layer.
C)soil temperature.
D)oxygen availability.

Question 43

Which of the following elements is considered a plant micronutrient?

A)iron
B)nitrogen
C)phosphorus
D)oxygen

Question 44

Compared with plants growing in sunlight,plants growing in shade tend to have a greater

A)rate of photosynthesis.
B)specific leaf area.
C)light compensation point.
D)light saturation point.

Question 45

All the following are plant adaptations to low temperatures,except

A)shedding leaves at the onset of cold weather.
B)production of antifreeze molecules.
C)a shifting of Topt.
D)increased photosynthetic rate to heat leaves.

Question 46

CAM plants

A)occur mostly in rainforests.
B)fix carbon dioxide during the night.
C)fix carbon dioxide in bundle sheath cells.
D)lack stomata.

Question 47

Compared with plants growing in shade,plants growing in sunlight tend to have smaller

A)stems.
B)roots.
C)leaves.
D)flowers.

Question 48

Carbon balance focuses on the balance between

A)uptake of CO₂ in photosynthesis and loss of heat via evapotranspiration.
B)loss of CO₂ through respiration and gain of nutrients.
C)loss of H₂O balanced with the gain of CO₂ via transpiration.
D)uptake of CO₂ in photosynthesis balanced with the loss of CO₂ during respiration.

Question 49

The rate of carbon uptake increases only when plants allocate carbon to the production of

A)roots.
B)fruits.
C)leaves and stems.
D)flowers.

Question 50

Plants using the C₄ photosynthetic pathway

A)use rubisco to catalyze the reaction between O₂ and RuBP.
B)have a lower rate of photosynthesis than plants using the C₃ photosynthetic pathway.
C)divide photosynthesis between mesophyll and bundle sheath cells.
D)are mostly trees.

Question 51

Net carbon uptake per unit time by a plant is directly related to

A)the difference between photosynthetic rate and respiration rate.
B)photosynthetic rate.
C)respiration rate.
D)the difference between photosynthetic rate and decomposition rate.

Question 52

The transfer of heat from the plant to the surrounding environment is influenced by the existence of the boundary layer,which refers to the layer of

A)waxy cutin on the surface of a leaf.
B)epidermal cells surrounding the stomata.
C)mesodermal cells beneath the epidermis.
D)still air or water adjacent to the surface of a leaf.

Question 53

Plants can reduce water loss by

A)closing their stomata.
B)growing larger leaves.
C)growing more slowly.
D)increasing photosynthesis.

Question 54

An Acacia seedling grown in shade (50% full sun)is expected to have a ________ net assimilation rate (NAR)and a ________ leaf area ratio (LAR)than an Acacia seedling grown in full sun.

A)higher; higher
B)lower; lower
C)lower; higher
D)higher; lower

Question 55

Compared with a shade-intolerant plant,a shade-tolerant plant

A)has a greater SLA.
B)grows faster.
C)requires a higher intake of CO₂ to balance losses of CO₂ from respiration.
D)allocates very little carbon to leaf tissue.

Question 56

The rates of photosynthesis and respiration in a plant are controlled by the temperature in the

A)soil.
B)air.
C)leaf.
D)root.

Question 57

The C₄ photosynthetic pathway is most common in

A)gymnosperm trees.
B)angiosperm trees.
C)algae,bryophytes,and ferns.
D)grasses and shrubs in warm and dry climates.

Question 58

Plants adapted to low-nutrient environments are characterized by

A)a high growth rate.
B)decreased root production.
C)increased leaf longevity.
D)faster growth when more nitrogen is available.

Question 59

Why is the SLA higher under shade for both shade-tolerant and shade-intolerant plants?

A)Shade intolerant plants have larger surface areas.
B)Leaves tend to be thicker in the shade.
C)Leaves tend to have larger surface areas to absorb more sunlight.
D)Shade tolerant plants have larger surface areas.

Question 60

Which of the following photosynthetic pathways is ideal for desert plants?

A)CAM
B)C₄
C)C₃
D)respiration

Question 61

Allocating carbon to the production of roots increases access to water and soil nutrients but limits carbon allocation to the production of leaves.

Question 62

Photosynthesis produces more water than it uses.

Question 63

Leaf area ratio (LAR)is the product of specific leaf area (SLA)and

A)net assimilation rate (NAR).
B)relative growth rate (RGR).
C)maximum net photosynthesis.
D)leaf weight ratio (LWR).

Question 64

In photosynthesis,the light-independent reactions do not directly require the presence of sunlight.

Question 65

In photosynthesis,carbon dioxide enters the leaf of a plant through its open stomata.

Question 66

Water moves from regions of high water potential to regions of low water potential.

Question 67

Some terrestrial plants use bicarbonate (HCO3-)as a carbon source for photosynthesis.

Question 68

The growth rate of plant cells and the efficiency of their physiological processes are highest when the cells are at minimum turgor.

Question 69

At light levels below the light compensation point,the rate of carbon loss due to respiration exceeds the rate of uptake in the process of photosynthesis.

Question 70

The drier the air outside a leaf,the faster is water lost from the leaf through the stomata.

Question 71

Wind or water flow functions to reduce the size of the boundary layer of leaves.

Question 72

Plants lose heat to the environment through direct contact of leaves with the air or water.

Question 73

Photoinhibition is the negative effect of high light levels on respiration.

Question 74

Under ideal conditions,when resources are unlimited,plant growth is maximized when carbon is allocated to the stem.

Question 75

Chemoautotrophs are the dominant primary producers in oxygen-deficient environments,such as the hydrothermal vents of the deep ocean floor.

Question 76

The light and dark reactions of photosynthesis occur in different areas of the chloroplast.

Question 77

Submerged aquatic plants typically have stomata.

Question 78

Allocation of carbon to roots directly increases both respiration and photosynthesis rates.

Question 79

Water in plants is lost to the atmosphere through the stomata.

Question 80

Which group of plants responds to increased CO₂ with the highest biomass enhancement ratio?

A)C₃
B)C₄
C)CAM
D)all respond equally