Deck 25: Growing a Green Thumb: Plant Physiology

Question 1

What is contained within the xylem sap of a plant?

A) water only
B) water and dissolved minerals only
C) water and sugars produced from photosynthesis only
D) water, dissolved minerals, and sugars

Answer 1

B

Question 2

Which adaptation is found in the leaves of cacti?

A) They store excess starch.
B) They are dropped during periods of drought.
C) They have been modified into spines.
D) They are very large to absorb plenty of sunlight.

Answer 2

C

Question 3

When can ice formation destroy plant cells?

A) as water flows into cells via osmosis as the temperature drops
B) as adhesion increases inside xylem tubes
C) as jagged ice crystals puncture cell membranes
D) as cells are poisoned by dissolved "antifreeze" solutes

Answer 3

C

Question 4

Which action is most similar to the way in which water is moved through the xylem sap of a plant?

A) a person drinking through a straw
B) a vaccine being ejected out of a syringe
C) water gushing up from a fountain
D) a dart being blown out the end of a blowgun

Question 5

Which type of plant would have the greatest rate of transpiration during the day?

A) a cactus
B) a plant with many large leaves
C) a plant with few and small leaves
D) a C₄ plant that grows in a hot, sunny, dry environment

Question 6

Which plant performs C₄ photosynthesis?

A) pineapple
B) sugarcane
C) jade plant
D) oak tree

Question 7

Which plant is best adapted to prevent an embolism in their xylem tubes?

A) a banana plant in a very warm climate
B) a spruce tree with narrow, tapering tracheids
C) a maple tree with wide, perforated vessel elements
D) a cattail in a marsh

Question 8

Which plants store CO₂ in the form of malic acid and close their stomata during the day?

A) C₃ plants
B) C₄ plants
C) CAM plants
D) hornworts and liverworts

Question 9

What is the tendency of water molecules to stick together?

A) cohesion
B) adhesion
C) tension
D) transpiration

Question 10

What type of force moves water up a tree, from its roots to its leaves?

A) pushing
B) pulling
C) pumping
D) positive pressure

Question 11

How can plants change rates of transpiration?

A) by changing the size of stomata openings
B) by making a cellulose plug in the xylem tubes
C) by promoting flowering
D) by reducing cohesion

Question 12

What force is created by the negative water pressure resulting from water evaporating from the stomata of a leaf?

A) cohesion
B) adhesion
C) tension
D) pressure flow

Question 13

What is the overall process illustrated by this diagram?

A) C₄ adaptations
B) CAM adaptations
C) apical dominance
D) transpiration

Question 14

What is the cold tolerance of a plant called?

A) photoperiodism
B) persistence
C) hardiness
D) apical dominance

Question 15

What will happen to a houseplant that's overwatered?

A) The leaves will burst.
B) The leaves will wilt.
C) The flowers will leak excess water.
D) It will grow faster than usual.

Question 16

Which plants drop their leaves on an annual basis?

A) annuals
B) perennials
C) deciduous
D) biennials

Question 17

Which action allows a plant to conserve water?

A) increasing photosynthesis during the day
B) opening stomata only at night
C) possessing large leaves
D) developing wide vessel elements

Question 18

What process is responsible for the flow of water through a plant, from the soil to the leaves?

A) translocation
B) transpiration
C) respiration
D) internal pumping

Question 19

Whereas vessel elements produce ________ friction on the flow of water than tracheids, they result in ________.

A) more; a reduced risk of an embolism
B) less; a greater risk of an embolism
C) more; reduced rates of water loss from leaves during a drought
D) less; the prevention of water loss from leaves during a drought

Question 20

Why DON'T water molecules located within a column of xylem sap move apart?

A) Cohesion holds the water molecules to each other; adhesion holds water molecules to the cellulose in plant cell walls.
B) Adhesion holds the water molecules to each other; tension holds water molecules to the cellulose in plant cell walls.
C) Tension holds the water molecules to each other; cohesion holds water molecules to the cellulose in plant cell walls.
D) Adhesion holds the water molecules to each other; cohesion holds water molecules to the cellulose in plant cell walls.

Question 21

When might cytosol leak into plant cell vacuoles?

A) if water freezes outside a plant cell
B) if water freezes inside a plant cell
C) if severe drought conditions shut down normal rates of transpiration
D) if the critical night length isn't met

Question 22

What do both the C₄ and CAM pathways of photosynthesis allow plants to do?

A) to perform photosynthesis in the absence of carbon dioxide
B) to outcompete C₃ plants in cool, dry conditions
C) to keep stomata partially or completely closed during the hottest parts of the day
D) to take up carbon dioxide at night and then store it as an acid until the day

Question 23

Why do florists and horticulturists often cut stems while they're holding a plant underwater?

A) to avoid transpiration
B) to prevent dormancy
C) to disrupt apical dominance
D) to avoid formation of an embolism

Question 24

What is the negative water pressure in the xylem of a plant?

A) torsion
B) cohesion
C) adhesion
D) tension

Question 25

What are the narrow, tapering cells found in the xylem tubes of drought-adapted plant species?

Question 26

What is the purpose for the process of deadheading?

A) It decreases the duration of flowering in an annual plant.
B) It removes fruits and seeds from plants when they're mature.
C) It allows the plant to produce and support more flowers than normal.
D) It reduces the amount of water needed by the plant.

Question 27

In what direction do the sugars in a peach tree move?

A) only toward the fruit
B) only toward the sugar source
C) only toward a sugar sink
D) either toward or away from sugar sources

Question 28

Where would you expect a plant with the largest leaves to grow?

A) in sunny conditions
B) in shady sites
C) in dry conditions
D) in very sandy soils

Question 29

Which phenomena drives transpiration in a terrestrial woody plant?

A) evaporation
B) gravitropism
C) translocation
D) photoperiodism

Question 30

Which structures are the water-conducting cells in mosses?

A) xylem cells
B) vessel elements
C) tracheids
D) hydroids

Question 31

Which plant has the greatest hardiness (can tolerate the lowest temperature)?

A) a tomato plant
B) a cabbage plant
C) an apple tree
D) a houseplant that evolved in the tropics

Question 32

Which plant closes its stomata during the day and conducts photosynthesis using chemically stored carbon?

A) moss
B) Kentucky bluegrass
C) jade plant
D) oak tree

Question 33

When have many deciduous plants adapted to drop their leaves?

A) when overwatered
B) during summer
C) during droughts
D) whenever daylight cycles shorten

Question 34

What is the time from the final frost in the spring to the first frost in the fall?

A) transpiration
B) hardiness
C) a growing season
D) translocation

Question 35

Which is an example of a CAM plant?

A) sugarcane
B) corn
C) crabgrass
D) aloe plant

Question 36

Plants that have undergone a gradual cooling period and are able to resist cold environmental temperatures are referred to as ________.

Question 37

What would plants living in areas with moist soils be most likely to have?

A) many narrow, tapering tracheids
B) lots of wide, perforated vessel elements
C) frequent embolisms and loss of tension
D) reduced transpiration rates

Question 38

In plants, what are embolisms?

A) toxic acids produced when stomata are closed and it's sunny
B) formations of ice crystals when a plant is subjected to below-freezing temperatures
C) hormones that result in apical dominance
D) air bubbles that form within xylem

Question 39

What might result from the overwatering of houseplants and garden plants?

A) an increase in chlorophyll within the leaves
B) decreased rates of transpiration
C) dormancy due to loss of leaves
D) the formation of hydroids

Question 40

What causes the "pulling" of a water column from the soil to the leaves?

A) hydrogen bonds
B) gravity
C) hardiness
D) active transport

Question 41

What is dormancy?

A) the ability of a plant to produce fruits
B) a plant's annual rest period
C) the period of time between flowering and fruiting
D) another term for translocation

Question 42

What effect does pruning flowers have on a plant?

A) The plant will make more flowers than normal.
B) The new flowers that grow will be larger.
C) The plant will produce more leaves.
D) The plant will produce fruits instead of flowers.

Question 43

In which direction would translocation occur in a pine tree?

A) from the roots to the needles
B) from pinecones to the roots
C) from the sugar source to the sink
D) from the sugar sink to the source

Question 44

What type of plants live for one year?

A) annuals
B) biennials
C) perennials
D) woody plants

Question 45

What is the tendency of a plant's uppermost bud to limit the growth of lower buds? (two words)

Question 46

What is the purpose of plant hormones?

A) They are produced in small amounts but have great effects.
B) They break down quickly after they are produced.
C) They act only at the location where they are produced.
D) They generally have one limited effect on the plant.

Question 47

Which chemical is photosensitive and allows plants to "measure" day length?

A) abscisic acid
B) malic acid
C) cytokinin
D) phytochrome

Question 48

What do the roots emerging from germinating seeds exhibit?

A) positive gravitropism
B) negative gravitropism
C) positive phototropism
D) negative phototropism

Question 49

In plants, how are the sugars produced from photosynthesis moved around?

A) via phloem sap
B) via xylem sap
C) via stomata
D) via embolisms

Question 50

A greenhouse manager wants to encourage long-term, productive flowering instead of short-term, rapid flowering in annual garden plants that are for sale. Which action would accomplish that goal?

A) pruning away early flowers
B) limiting water and fertilizer
C) moving the plants to the shadiest part of the greenhouse
D) allowing any flowers to become fruits and seeds

Question 51

Which process occurs when a grapevine wraps around a trellis or another supporting structure?

A) photoperiodism
B) thigmotropism
C) gravitropism
D) phototropism

Question 52

If the sugary phloem sap in a fruit tree is divided into many sugar sinks, then how will each individual fruit be affected?

A) The fruit will be small and sugary.
B) The fruit will be large and sugary.
C) The fruit will be small and diluted.
D) The fruit will be large and diluted.

Question 53

Photoperiodic plants react to a certain amount of darkness, referred to as ________ (three words).

Question 54

What will happen after a gardener cuts off all the developing flowers on a tomato plant, with the exception of 12 of the flowers that have already been pollinated and set fruit?

A) The tomato plant will drop the 12 previously pollinated flowers.
B) The tomato plant will become dormant until next year and then 12 tomatoes will ripen.
C) The 12 tomatoes will develop fully on the plant, but they will be small and not very sweet.
D) The 12 tomatoes will develop, and they will be larger and sweeter than if the other flowers remained.

Question 55

What type of plants flower only if day length is less than a critical value?

A) short-day plants
B) long-day plants
C) biennial plants
D) perennial plants

Question 56

Many garden plants that are grown for leaves or roots, such as parsley and carrots, produce vegetative growth the first year and reproductive structure growth the second year. Thus, what type of plants are parsley and carrots?

A) annuals
B) biennials
C) perennials
D) woody plants

Question 57

Which plant is a perennial?

A) peony
B) morning glory
C) petunia
D) pansy

Question 58

What is the first step in the pressure flow mechanism of translocation?

A) Sugar is loaded into the xylem at the source.
B) Sugar is loaded into the phloem at the source.
C) Water is loaded into the phloem at the source.
D) Water is loaded into the phloem at the sink.

Question 59

Which plants live for many years and produce flowers every year?

Question 60

What is the response of a plant to the proportion of light and dark in a day?

Question 61

Through what process do deciduous plants drop their leaves?

A) thigmotropism
B) gravitropism
C) abscission
D) photoperiodism

Question 62

What can a person do to the topmost leaves and buds, resulting in reduced apical dominance in order to make a shrub bushier?

A) deadhead
B) harden
C) pinch back
D) translocate

Question 63

Which hormone promotes the abscission of leaves and fruits?

A) auxin
B) ethylene
C) cytokinin
D) gibberellin

Question 64

Which plant hormone is responsible for apical dominance?

A) auxin
B) ethylene
C) cytokinin
D) gibberellin

Question 65

What is the tendency for plants that live on other plants (epiphytes) to send shoots upward while sending roots down toward the ground?

A) positive and negative gravitropism
B) positive and negative thigmotropism
C) negative and positive gravitropism
D) negative and positive thigmotropism

Question 66

Which hormone plays an "anti-abscission role" in plants?

A) auxin
B) ethylene
C) gibberellin
D) cytokinin