TEST 2 TESTBANK 29,30,35,36

Question 1

All of the following are common to both charophytes and land plants except
A) sporopollenin.
B) lignin.
C) chlorophyll a.
D) cellulose.
E) chlorophyll b.

Answer 1

B) lignin.

Question 2

In animal cells and in the meristem cells of land plants, the nuclear envelope disintegrates during mitosis. This disintegration does not occur in the cells of most protists and fungi. According to our current knowledge of plant evolution, which group of organisms should feature mitosis most similar to that of land plants?
A) unicellular green algae
B) cyanobacteria
C) charophytes
D) red algae
E) multicellular green algae

Answer 2

C) charophytes

Question 3

What is true of charophytes?
A) They are the ancestors of green algae.
B) They are examples of seedless vascular plants.
C) They are the closest living algal relatives of land plants.
D) They share some features in common with land plants, namely spores surrounded by sporopollenin and alternation of generations.

Answer 3

C) They are the closest living algal relatives of land plants.

Question 4

The most recent common ancestor of all land plants was probably similar to modern -day members of which group?
A) green algae 
B) red algae
C) charophytes 
D) brown algae 
E) angiosperms

Answer 4

C) charophytes

Question 5

protection from desiccation 
A) tracheids and phloem
B) secondary compounds
C) cuticle
D) alternation of generations

Answer 5

C) cuticle

Question 6

transport of water, minerals, and nutrients 
A) tracheids and phloem
B) secondary compounds
C) cuticle
D) alternation of generations
Answer: A

Answer 6

A) tracheids and phloem

Question 7

Which event during the evolution of land plants probably made the synthesis of secondary compounds most beneficial?
A) the greenhouse effect present throughout the Devonian period B) the reverse-greenhouse effect during the Carboniferous period
C) the association of the roots of land plants with fungi
D) the rise of herbivory
E) the rise of wind pollination

Answer 7

D) the rise of herbivory

PREDATORS

Question 8

Which taxon is essentially equivalent to the ʺembryophytesʺ? 
A) Viridiplantae 

B) Plantae

C) Pterophyta 
D) Bryophyta 

E) Charophycea

Answer 8

A) Viridiplantae 


Question 9

Which of the following taxa includes the largest amount of genetic diversity among plantlike organisms? 

A) Embryophyta 
B) Viridiplantae 

C) Plantae

D) Charophyceae 

E) Tracheophyta

Answer 9

B) Viridiplantae 


Question 10

Bryophytes have all of the following characteristics except A) multicellularity.

B) specialized cells and tissues. C) lignified vascular tissue.

D) walled spores in sporangia.

E) a reduced, dependent sporophyte.

Answer 10

C) lignified vascular tissue.


Question 11

A botanist discovers a new species of plant in a tropical rain forest. After observing its anatomy and life cycle, the following characteristics are noted: flagellated sperm, xylem with tracheids, separate gametophyte and sporophyte generations with the sporophyte dominant, and no seeds. This plant is probably most closely related to 

A) mosses.

B) charophytes. 

C) ferns.

D) gymnosperms. 

E) flowering plants.

Answer 11

C) ferns.


Question 12

Which of the following types of plants would not yet have been evolved in the forests that became coal deposits? 

A) horsetails 
B) lycophytes 

C) pine trees 
D) tree ferns 

E) whisk ferns

Answer 12

C) pine trees

Question 13

If humans had been present to build log structures during the Carboniferous period (they werenʹt), which plant type(s) would have been suitable sources of logs?

A) whisk ferns and epiphytes
B) horsetails and bryophytes
C) lycophytes and bryophytes 

D) ferns, horsetails, and lycophytes

E) charophytes, bryophytes, and gymnosperms

Answer 13

D) ferns, horsetails, and lycophytes


Question 14

Which of the following is a land plant that produces flagellated sperm and has a sporophyte-dominated life cycle? 

A) moss 
B) fern 

C) liverwort 
D) charophyte 

E) hornwort

Answer 14

B) fern 


Question 15

Bryophytes never formed forests (mats, yes, but not forests) because
A) they possess flagellated sperms. 

B) not all are heterosporous.

C) they lack lignified vascular tissue.

D) they have no adaptations to prevent desiccation.

E) the sporophyte is too weak.

Answer 15

C) they lack lignified vascular tissue.


Question 16

Of the following list, flagellated (swimming) sperm are generally present in which groups?

1. Lycophyta
2. Bryophyta
3. Angiosperms
4. Chlorophyta
5. Pterophyta

A) 1, 2, 3 B) 1, 2, 4, 5 C) 1,3,4,5
D) 2, 3, 5 E) 2, 3, 4, 5

Answer 16

B) 1, 2, 4, 5

Question 17

Which of the following is a true statement about plant reproduction?

A) ʺEmbryophytesʺ are small because they are in an early developmental stage. 

B) Both male and female bryophytes produce gametangia. C) Gametangia protect gametes from excess water.

D) Eggs and sperm of bryophytes swim toward one another. 

E) Bryophytes are limited to asexual reproduction.

Answer 17

B) Both male and female bryophytes produce gametangia.

Question 18

Each of the following is a general characteristic of bryophytes except 
A) a cellulose cell wall. 

B) vascular tissue.

C) chlorophylls a and b.

D) being photosynthetic autotrophs. 

E) being eukaryotic.

Answer 18

B) vascular tissue.


Question 19

The sporophytes of mosses depend on the gametophytes for water and nutrition. In seed plants, the reverse is true. From which seed plant sporophyte structure(s) do the immature (unfertilized) gametophytes directly gain water and nutrition? 
A) sporophylls 
B) embryos 
C) sporangia

D) sporopollenin 
E) ovary

Answer 19

C) sporangia


Question 20

Which of the following is an ongoing trend in the evolution of land plants?
A) decrease in the size of the leaf
B) reduction of the gametophyte phase of the life cycle

C) elimination of sperm cells or sperm nuclei

D) increasing reliance on water to bring sperm and egg together
E) replacement of roots by rhizoids

Answer 20

B) reduction of the gametophyte phase of the life cycle


Question 21

The main way that pine trees disperse their offspring is by using
A) fruits that are eaten by animals. 
B) spores.

C) squirrels to bury cones.
D) windblown seeds. 

E) flagellated sperm swimming through water

Answer 21

D) windblown seeds. 


Question 22

Which feature of cycads distinguishes them from most other gymnosperms? 
1. They have exposed ovules.

2. They have flagellated sperm.

3. They are pollinated by animals. 
A) 1 only 
B) 2 only 
C) 3 only 
D) 2 and 3

E) 1, 2, and 3

Answer 22

D) 2 and 3


Question 23

What is true of stamens, sepals, petals, carpels, and pinecone scales? 
A) They are female reproductive parts. 
B) None are capable of photosynthesis. 
C) They are modified leaves.

D) They are found on flowers. 
E) They are found on angiosperms.

Answer 23

C) They are modified leaves.


Question 24

Given the differences between angiosperms and gymnosperms in the development of the integument(s), which of these statements is the most logical consequence?
A) The seed coats of angiosperms should be relatively thicker than those of gymnosperms. 

B) It should be much more difficult for pollen tubes to enter angiosperm ovules than for them to enter gymnosperm ovules. 

C) The female gametophytes of angiosperms should not be as well protected from environmental stress as should those of gymnosperms. 

D) As a direct consequence of such differences, angiosperms should have fruit. 

E) Angiosperm seeds should be more susceptible to desiccation. 


Answer 24

A) The seed coats of angiosperms should be relatively thicker than those of gymnosperms.

Question 25

How have fruits contributed to the success of angiosperms?
A) by nourishing the plants that make them 

B) by facilitating dispersal of seeds

C) by attracting insects to the pollen inside

D) by producing sperm and eggs inside a protective coat 

E) by producing triploid cells via double fertilization

Answer 25

B) by facilitating dispersal of seeds


Question 26

Arrange the following structures from largest to smallest, assuming that they belong to two generations of the same angiosperm.
1. ovary
2. ovule 
3. egg
4. carpel
5. embryo sac 

A) 4, 2, 1, 5, 3 
B) 4, 5, 2, 1, 3 
C) 5,4,3,1,2 
D) 5, 1, 4, 2, 3 
E) 4, 1, 2, 5, 3

Answer 26

E) 4, 1, 2, 5, 3

Question 27

Hypothetically, one of the major benefits of double fertilization in angiosperms is to
A) decrease the potential for mutation by insulating the embryo with other cells. 

B) increase the number of fertilization events and offspring produced.

C) promote diversity in flower shape and color.

D) coordinate developmental timing between the embryo and its food stores. 

E) emphasize embryonic survival by increasing embryo size.

Answer 27

D) coordinate developmental timing between the embryo and its food stores.

Question 28

Angiosperms are the most successful terrestrial plants. Which of these features is unique to them and helps account for their success? 

A) wind pollination

B) dominant gametophytes 

C) fruits enclosing seeds

D) embryos enclosed within seed coats 

E) sperm cells without flagella

Answer 28

C) fruits enclosing seeds


Question 29

Which of the following is not a characteristic that distinguishes gymnosperms and angiosperms from other plants? 

A) alternation of generations 
B) ovules 

C) integuments 
D) pollen 

E) dependent gametophytes

Answer 29

A) alternation of generations

Question 30

Gymnosperms and angiosperms have the following in common except 
A) seeds. 

B) pollen.

C) vascular tissue. 
D) ovaries. 

E) ovules.

Answer 30

D) ovaries.

Question 31

All of the following cellular structures are functionally important in cells of the gametophytes of both angiosperms and gymnosperms, except 

A) haploid nuclei. 
B) mitochondria. 

C) cell walls. 
D) chloroplasts. 

E) peroxisomes

Answer 31

D) chloroplasts.

Question 32

In seed plants, which part of a pollen grain has a function most like that of the seed coat? 
A) sporophyll 

B) male gametophyte 
C) sporopollenin

D) stigma 

E) sporangium

Answer 32

C) sporopollenin


Question 33

Which of these is most important in making the typical seed more resistant to adverse conditions than the typical spore? 

A) a different type of sporopollenin

B) an internal reservoir of liquid water

C) integument(s)

D) ability to be dispersed 

E) waxy cuticle

Answer 33


C) integument(s)

Question 34

The seeds of orchids are among the smallest known, with virtually no endosperm and with miniscule seed leaves. Consequently, what should one expect to be true of such seeds?

A) They require extensive periods of dormancy during which the embryo develops.

B) They are surrounded by brightly colored, sweet fruit.

C) They germinate very soon after being released from the ovary.

D) The developing embryo within is dependent upon the gametophyte for nutrition. 

E) The sporophytes that produce such seeds are wind pollinated.

Answer 34

C) They germinate very soon after being released from the ovary.

Question 35

The fruit is made of material high in calories. A) animal skin, fur, or feathers 
B) animal digestive tract C) water currents
D) gravity and terrain 
E) air currents

Answer 35

B) animal digestive tract

Question 36

The fruit is covered with spines or hooks. A) animal skin, fur, or feathers 
B) animal digestive tract C) water currents
D) gravity and terrain 
E) air currents

Answer 36

A) animal skin, fur, or feathers

Question 37

The fruit contains an air bubble. A) animal skin, fur, or feathers 
B) animal digestive tract C) water currents
D) gravity and terrain 
E) air currents

Answer 37

C) water currents


Question 38

The fruit has a heavy weight and spheroidal shape. A) animal skin, fur, or feathers 
B) animal digestive tract C) water currents
D) gravity and terrain 
E) air currents

Answer 38


D) gravity and terrain

Question 39

The fruit has light, fibrous plumes. A) animal skin, fur, or feathers 
B) animal digestive tract C) water currents
D) gravity and terrain 
E) air currents

Answer 39

E) air currents

Question 40

Carpels and stamens are
A) sporophyte plants in their own right. 
B) gametophyte plants in their own right. C) gametes.
D) spores. 
E) modified sporophylls.

Answer 40

E) modified sporophylls.

Question 41

Which of the following flower parts develops into a seed? A) ovule 
B) ovary C) fruit D) style 
E) stamen

Answer 41

A) ovule

Question 42

Which of the following flower parts develops into the pulp of a fleshy fruit? A) stigma 
B) style C) ovule D) ovary 
E) micropyle

Answer 42

D) ovary

Question 43

A plant whose reproductive parts produce nectar is also most likely to
A) have brightly colored reproductive parts. 
B) produce sweet-tasting fruit.
C) rely on wind pollination.
D) have no parts that can perform photosynthesis. 
E) suffer significant seed loss to sugar-seeking insects.

Answer 43

A) have brightly colored reproductive parts.

Question 44

Which is a true statement about angiosperm carpels?
A) Carpels are features of the gametophyte generation. 
B) Carpels consist of anther and stamen.
C) Carpels are structures that directly produce male gametes. D) Carpels surround and nourish the female gametophyte. 
E) Carpels consist of highly modified microsporangia.

Answer 44

D) Carpels surround and nourish the female gametophyte.

Question 45

Which feature of cycads makes them similar to many angiosperms? 
1. They have exposed ovules.

2. They have flagellated sperm.

3. They are pollinated by animals. 
A) 1 only 
B) 2 only 
C) 3 only 

D) 2 and 3

E) 1, 2, and 3

Answer 45

C) 3 only

Question 46

Which of these statements is true of the pine life cycle?
A) Cones are homologous to the capsules of moss plants. 
B) The pine tree is a gametophyte.
C) Male and female gametophytes are in close proximity during gamete synthesis. D) Conifer pollen grains contain male gametophytes. 
E) Double fertilization is a relatively common phenomenon.

Answer 46

D) Conifer pollen grains contain male gametophytes.

Question 47

Which structure is common to both gymnosperms and angiosperms? A) stigma 
B) carpel C) ovule D) ovary 
E) anthers

Answer 47

C) ovule

Question 48

Which trait(s) is (are) shared by many modern gymnosperms and angiosperms? 1. pollen transported by wind
2. lignified xylem
3. microscopic gametophytes 
4. sterile sporophylls, modified to attract pollinators 5. endosperm 
A) 1 only B) 1 and 3 
C) 1,2,and3 D) 1, 3, and 5 E) 2, 4, and 5

Answer 48

C) 1,2,and3

Question 49

A fruit is most commonly A) a mature ovary. 
B) a thickened style. C) an enlarged ovule. D) a modified root. 
E) a mature female gametophyte.

Answer 49

A) a mature ovary.

Question 50

Many mammals have skins and mucous membranes that are sensitive to phenolic secretions of plants like poison oak (Rhus). These secondary compounds are primarily adaptations that 
A) prevent desiccation. B) favor pollination. 
C) foster seed dispersal. D) decrease competition. 
E) inhibit herbivory.

Answer 50

E) inhibit herbivory

Question 51

On the Pacific island of Guam, large herbivorous bats called ʺflying foxesʺ commonly feed on cycad seeds, a potent source of neurotoxins. The flying foxes do not visit male cones. Consequently, what should be true?
. A) The flying foxes are attracted to cycad fruit, and eat the enclosed seeds only by accident. 

. B) Flying foxes are highly susceptible to the effects of the neurotoxins. 

. C) The flying foxes assist the beetles as important pollinating agents of the cycads. 

. D) Flying foxes can be dispersal agents of cycad seeds if the seeds sometimes get 
swallowed whole (i.e., without getting chewed). 


Answer 51

D) Flying foxes can be dispersal agents of cycad seeds if the seeds sometimes get 
swallowed whole (i.e., without getting chewed). 


Question 52

Which structure is incorrectly paired with its tissue system? A) root hair

Answer 52

D) companion cell

Question 53

Land plants are composed of all the following tissue types except A) mesodermal. 
B) epidermal. C) meristematic. D) vascular. 
E) ground tissue.

Answer 53

A) mesodermal.

Question 54

Vascular plant tissue includes all of the following cell types except A) vessel elements. 
B) sieve cells.
C) tracheids.
D) companion cells. 
E) cambium cells.

Answer 54

E) cambium cells.

Question 55

Which of the following are the water-conducting cells of xylem, have thick walls, and are dead at functional maturity? 
A) parenchyma cells B) collenchyma cells C) clerenchyma cells 
D) tracheids and vessel elements E) sieve-tube elements

Answer 55


D) tracheids and vessel elements

Question 56

Which of the following are sugar-transporting cells in angiosperms? A) parenchyma cells 
B) collenchyma cells
C) clerenchyma cells
D) tracheids and vessel elements 
E) sieve-tube elements

Answer 56

E) sieve-tube elements

Question 57

Which cells are no longer capable of carrying out the process of DNA transcription? A) xylem 
B) sieve tube elements C) companion cells
D) A and B only 
E) A, B and C

Answer 57


D) A and B only

Question 58

__________ is to xylem as __________ is to phloem. A) Sclerenchyma cell; parenchyma cell 
B) Apical meristem; vascular cambium C) Vessel element; sieve-tube member D) Cortex; pith 
E) Vascular cambium; cork cambium

Answer 58

C) Vessel element; sieve-tube member

Question 59

Which of the following have unevenly thickened primary walls that support young, growing parts of the plant? 
A) parenchyma cells B) collenchyma cells C) clerenchyma cells 
D) tracheids and vessel elements E) sieve-tube elements

Answer 59

B) collenchyma cells

Question 60

Which of the following are true statements about the cells shown in the photograph in Figure 35.1 above? 
A) They are parenchyma cells. B) They are photosynthetic. 
C) They are usually found in roots. D) They are phloem cells. 
E) Both A and B.

Answer 60

E) Both A and B.

Question 61

A student examining leaf cross sections under a microscope finds many loosely packed cells with relatively thin cell walls. The cells have numerous chloroplasts. What type of cells are these? 
A) parenchyma B) xylem 
C) endodermis D) collenchyma 
E) sclerenchyma

Answer 61

A) parenchyma

Question 62

Before differentiation can begin during the processes of plant cell and tissue culture, parenchyma cells from the source tissue must 
A) differentiate into procambium. B) undergo dedifferentiation. 
C) increase the number of chromosomes in their nuclei. D) enzymatically digest their primary cell walls. 
E) establish a new polarity in their cytoplasm.

Answer 62

B) undergo dedifferentiation.

Question 63

Which of the following are relatively unspecialized cells that retain the ability to divide and perform most of the plantʹs metabolic functions of synthesis and storage? 
A) parenchyma cells B) collenchyma cells C) clerenchyma cells 
D) tracheids and vessel elements E) sieve-tube elements

Answer 63

A) parenchyma cells

Question 64

For this pair of items, choose the option that best describes their relationship. (A) the thickness of the cell wall of sclerenchyma
(B) the thickness of the cell wall of parenchyma 
A) Item (A) is greater than item (B).
B) Item (A) is less than item (B). 
C) Item (A) is exactly or very approximately equal to item (B).
D) Item (A) may stand in more than one of the above relations to item (B).

Answer 64

A) Item (A) is greater than item (B).

Question 65

Which of the following is incorrectly paired with its structure and function?
A) sclerenchyma-supporting cells with thick secondary walls 
B) periderm-protective coat of woody stems and roots

C) pericycle-waterproof ring of cells surrounding the central stele in roots
D) mesophyll-parenchyma cells functioning in photosynthesis in leaves 

E) ground meristem-primary meristem that produces the ground tissue system

Answer 65

C) pericycle-waterproof ring of cells surrounding the central stele in roots

Question 66

A leaf primordium is initiated as a small mound of tissue on the flank of a dome-shaped shoot apical meristem. The earliest physical evidence of the site of a newly forming leaf primordium would be
. A) development of chloroplasts in a surface cell of the shoot apical meristem. 

. B) cell division in the shoot apical meristem with the newly forming walls perpendicular 
to the surface of the meristem. 

. C) pre-prophase bands parallel to the surface of the meristem in subsurface cells of the 
shoot apical meristem. 

. D) elongation of epidermal cells perpendicular to the surface of the shoot apical 
meristem. 

. E) formation of stomata in the epidermal layer of the shoot apical meristem.

Answer 66

C) pre-prophase bands parallel to the surface of the meristem in subsurface cells of the 
shoot apical meristem. 


Question 67

Cells produced by lateral meristems are known as
A) dermal and ground tissue. 
B) lateral tissues.

C) pith.

D) secondary tissues. 

E) shoots and roots.

Answer 67

D) secondary tissues.

Question 68

The phase change of an apical meristem from the juvenile to the mature vegetative phase is often revealed by
. A) a change in the morphology of the leaves produced. 

. B) the initiation of secondary growth. 

. C) the formation of lateral roots. 

. D) a change in the orientation of preprophase bands and cytoplasmic microtubules in 
lateral meristems. 

. E) the activation of floral meristem identity genes.

Answer 68

A) a change in the morphology of the leaves produced. 


Question 69

Which of the following arise from meristematic activity? A) secondary xylem 
B) leaves
C) dermal tissue D) tubers 
E) all of the above

Answer 69

D) tubers

Question 70

Pinching off the tops of snapdragons causes the plants to make many more flowers than they would if left alone. Why does removal of the top cause more flowers to form?
. A) Removal of an apical meristem causes a phase transition from vegetative to floral development. 

. B) Removal of an apical meristem causes cell division to become disorganized, as in the fass mutant of Arabidopsis. 

. C) Removal of an apical meristem allows more nutrients to be delivered to floral meristems. 

. D) Removal of an apical meristem causes outgrowth of lateral buds that produce extra branches, which ultimately produce flowers. 

. E) Removal of an apical meristem allows the periderm to produce new lateral branches. 


Answer 70

D) Removal of an apical meristem causes outgrowth of lateral buds that produce extra branches, which ultimately produce flowers. 


Question 71

For this pair of items, choose the option that best describes their relationship. (A) the probability that xylem cells are meristematic
(B) the probability that trichomes are meristematic 
A) Item (A) is greater than item (B).
B) Item (A) is less than item (B). 
C) Item (A) is exactly or very approximately equal to item (B).
D) Item (A) may stand in more than one of the above relations to item (B).

Answer 71

C) Item (A) is exactly or very approximately equal to item (B)

Question 72

Plants contain meristems whose only function is to 
A) attract pollinators. 

B) absorb ions.

C) photosynthesize. 
D) divide. 

E) produce flowers.

Answer 72

D) divide. 


Question 73

Which of the following arise from lateral meristem activity? A) secondary xylem 
B) leaves
C) trichomes D) tubers 
E) all of the above

Answer 73

A) secondary xylem

Question 74

The driving force that pushes the root tip through the soil is due primarily to
A) continuous cell division in the root cap at the tip of the root. 

B) continuous cell division just behind the root cap in the center of the apical meristem.
C) elongation of cells behind the root apical meristem.

D) A and B only.

E) A, B, and C.

Answer 74

C) elongation of cells behind the root apical meristem.


Question 75

Axillary buds

A) are initiated by the cork cambium. 

B) develop from meristematic cells left by the apical meristem. C) are composed of a series of internodes lacking nodes.

D) grow immediately into shoot branches.

E) do not form a vascular connection with the primary shoot.

Answer 75

B) develop from meristematic cells left by the apical meristem.

Question 76

Which of the following is not part of an older treeʹs bark? A) cork 
B) cork cambium C) lenticels
D) secondary xylem 
E) secondary phloem

Answer 76


D) secondary xylem

Question 77

Heartwood and sapwood consist of A) bark. 
B) periderm.
C) secondary xylem. D) secondary phloem. 
E) cork.

Answer 77

C) secondary xylem.

Question 78

What tissue makes up most of the wood of a tree? A) primary xylem 
B) secondary xylem C) secondary phloem D) mesophyll cells 
E) vascular cambium

Answer 78

B) secondary xylem

Question 79

One important difference between the anatomy of roots and the anatomy of leaves is that A) only leaves have phloem and only roots have xylem. 

B) the cells of roots have cell walls and leaf cells do not.

C) a waxy cuticle covers leaves but is absent in roots.

D) vascular tissue is found in roots but is absent from leaves. 

E) leaves have epidermal tissue but roots do not.

Answer 79

C) a waxy cuticle covers leaves but is absent in roots.


Question 80

The best word to describe the growth of plants in general is 
A) perennial. 

B) weedy.

C) indeterminate. 
D) derivative. 

E) primary.

Answer 80


C) indeterminate.

Question 81

All of the following cell types are correctly matched with their functions except
A) mesophyll-photosynthesis. 

B) guard cell-regulation of transpiration.
C) sieve-tube member-translocation.

D) vessel element-water transport. 
E) companion cell-formation of secondary xylem and phloem.

Answer 81


E) companion cell-formation of secondary xylem and phloem.

Question 82

The vascular system of a three-year-old eudicot stem consists of A) 3 rings of xylem and 3 of phloem. 
B) 2 rings of xylem and 2 of phloem. C) 2 rings of xylem and 1 of phloem. D) 2 rings of xylem and 3 of phloem. E) 3 rings of xylem and 1 of phloem.

Answer 82

E) 3 rings of xylem and 1 of phloem.

Question 83

Suppose George Washington completely removed the bark from around the base of a cherry tree but was stopped by his father before cutting the tree down. The leaves retained their normal appearance for several weeks, but the tree eventually died. The tissue(s) that George left functional was (were) the 

A) phloem. 
B) xylem. 

C) cork cambium. 
D) cortex. 

E) companion and sieve-tube members.

Answer 83

B) xylem. 


Question 84

Pine seedlings grown in sterile potting soil grow much slower than seedlings grown in soil from the area where the seeds were collected. This is most likely because 
A) the sterilization process kills the root hairs as they emerge from the seedling. B) the normal symbiotic fungi are not present in the sterilized soil. 
C) sterilization removes essential nutrients from the soil.
D) water and mineral uptake is faster when mycorrhizae are present. 
E) B and D

Answer 84

E) B and D

Question 85

What is the main cause of guttation in plants? A) root pressure 
B) transpiration
C) pressure flow in phloem D) plant injury 
E) condensation of atmospheric water

Answer 85

A) root pressure

Question 86

One is most likely to see guttation in small plants when the A) transpiration rates are high. 
B) root pressure exceeds transpiration pull.
C) preceding evening was hot, windy, and dry. D) water potential in the stele of the root is high. 
E) roots are not absorbing minerals from the soil.

Answer 86


B) root pressure exceeds transpiration pull.

Question 87

What regulates the flow of water through the xylem? A) passive transport by the endodermis 
B) the number of companion cells in the phloem C) the evaporation of water from the leaves
D) active transport by sieve-tube members 
E) active transport by tracheid and vessel elements.

Answer 87

C) the evaporation of water from the leaves


Question 88

What is the main force by which most of the water within xylem vessels moves toward the top of a tree? 
A) active transport of ions into the stele B) atmospheric pressure on roots 
C) evaporation of water through stoma D) the force of root pressure 
E) osmosis in the root

Answer 88

C) evaporation of water through stoma

Question 89

In which plant cell or tissue would the pressure component of water potential most often be negative? 
A) leaf mesophyll cell B) stem xylem 
C) stem phloem D) root cortex cell E) root epidermis

Answer 89

B) stem xylem

Question 90

Water potential is generally most negative in which of the following parts of a plant? A) mesophyll cells of the leaf 
B) xylem vessels in leaves C) xylem vessels in roots D) cells of the root cortex 
E) root hairs

Answer 90

A) mesophyll cells of the leaf

Question 91

Which of the following has the lowest (most negative) water potential? A) soil 
B) root xylem C) trunk xylem D) leaf cell walls 
E) leaf air spaces

Answer 91


E) leaf air spaces

Question 92

Transpiration in plants requires all of the following except A) adhesion of water molecules to cellulose. 
B) cohesion between water molecules. C) evaporation of water molecules.
D) active transport through xylem cells. 
E) transport through tracheids.

Answer 92

D) active transport through xylem cells.

Question 93

The water lost during transpiration is an unfortunate side effect of the plantʹs exchange of gases. However, the plant derives some benefit from this water loss in the form of 
A) evaporative cooling. B) mineral transport. 
C) increased turgor. D) A and B only 
E) A, B, and C

Answer 93

D) A and B only

Question 94

Xylem vessels, found in angiosperms, have a much greater internal diameter than tracheids, the only xylem conducting cells found in gymnosperms. The tallest living trees, redwoods, are gymnosperms. Which of the following is an advantage of tracheids over vessels for long-distance transport to great heights?
. A) Adhesive forces are proportionally greater in narrower cylinders than in wider cylinders. 

. B) The smaller the diameter of the xylem, the more likely cavitation will occur. 

. C) Cohesive forces are greater in narrow tubes than in wide tubes of the same height. 

. D) Only A and C are correct. 

. E) A, B, and C are correct.

Answer 94

D) Only A and C are correct.

Question 95

All of the following are adaptations that help reduce water loss from a plant except 
A) transpiration. 

B) sunken stomata. 
C) C4 photosynthesis. 

D) small, thick leaves.

E) crassulacean acid metabolism.

Answer 95

A) transpiration

Question 96

What is the driving force for the movement of materials in the phloem of plants? A) gravity 
B) a difference in osmotic water potential between the source and the sink. C) root pressure
D) transpiration of water through the stomates 
E) adhesion of water to phloem sieve tubes

Answer 96

B) a difference in osmotic water potential between the source and the sink

Question 97

Phloem transport of sucrose can be described as going from ʺsource to sink.ʺ Which of the following would not normally function as a sink? 
A) growing leaf B) growing root 
C) storage organ in summer D) mature leaf 
E) shoot tip

Answer 97

D) mature leaf

Question 98

Which of the following is a correct statement about sugar movement in phloem? A) Diffusion can account for the observed rates of transport. 
B) Movement can occur both upward and downward in the plant. C) Sugar is translocated from sinks to sources.
D) Only phloem cells with nuclei can perform sugar movement. 
E) Sugar transport does not require energy. 


Answer 98


B) Movement can occur both upward and downward in the plant.

Question 99

Phloem transport is described as being from source to sink. Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring? Phloem transports __________ from the __________ source to the __________ sink. 

A) amino acids; root; mycorrhizae B) sugars; leaf; apical meristem 

C) nucleic acids; flower; root
D) proteins; root; leaf

E) sugars; stem; root

Answer 99

B) sugars; leaf; apical meristem

Question 100

Arrange the following five events in an order that explains the mass flow of materials in the phloem. 
1. Water diffuses into the sieve tubes.
2. Leaf cells produce sugar by photosynthesis.
3. Solutes are actively transported into sieve tubes. 4. Sugar is transported from cell to cell in the leaf. 5. Sugar moves down the stem. 

A) 2, 1, 4, 3, 5 
B) 1, 2, 3, 4, 5 
C) 2,4,3,1,5 
D) 4, 2, 1, 3, 5 
E) 2, 4, 1, 3, 5

Answer 100

C) 2,4,3,1,5

Question 101

Root hairs are most important to a plant because they
A) anchor a plant in the soil.

B) store starches.

C) increase the surface area for absorption.

D) provide a habitat for nitrogen-fixing bacteria.

E) contain xylem tissue.

Answer 101

C) increase the surface area for absorption.

Question 102

What is the role of proton pumps in root hair cells? 
A) establish ATP gradients 

B) acquire minerals from the soil
C) pressurize xylem transport 
D) eliminate excess electrons 

E) A and D only

Answer 102

B) acquire minerals from the soil

Question 103

In plant roots, the Casparian strip is correctly described by which of the following?
. A) It is located in the walls between endodermal cells and cortex cells. 

. B) It provides energy for the active transport of minerals into the stele from the cortex. 

. C) It ensures that all minerals are absorbed from the soil in equal amounts. 

. D) It ensures that all water and dissolved substances must pass through a cell membrane 
before entering the stele. 

. E) It provides increased surface area for the absorption of mineral nutrients.

Answer 103

. D) It ensures that all water and dissolved substances must pass through a cell membrane 
before entering the stele. 


Question 104

Active transport would be least important in the normal functioning of which of the following plant tissue types? 

A) leaf transfer cells 
B) stem xylem 

C) root endodermis 
D) leaf mesophyll 

E) root phloem

Answer 104

B) stem xylem