Plants Chaps 21-23
True/False (1 point each)
Indicate whether the statement is true or false.
____
1. Like plants, green algae store food as starch.
____
2. A landscaper has several choices of trees for you to pick from to plant in your yard. You have narrowed the
choice to two—a male conifer and a female ginkgo. Because you have allergies to pollen, the ginkgo is your
better choice.
____
3. During the evolution of plants there has been a transition from a dominant sporophyte plant to a dominant
gametophyte plant.
____
4. Leaves of a tropical rain forest plant would have fewer stomata per square centimeter of surface than leaves of
a cold climate plant.
____
5. The rate of photosynthesis decreases when a plant’s stomata close.
____
6. The primary function of meristematic tissue is plant growth.
____
7. The life cycle of mosses does not exhibit alteration of generations.
____
8. Male flowers release pollen grains.
____
9. The gametophyte generation of anthophytes is dominant and supports the sporophyte generation.
____ 10. The style directs the growth of the pollen tube.
Multiple Choice (2 points each)
Identify the choice that best completes the statement or answers the question.
Figure 21-1
____ 11. Refer to Figure 21-1. Removing which structure would cause this plant to starve?
a. A
c. C
b. B
d. D
____ 12. If the plant described in Figure 21-1 has 16 chromosomes in the gametophyte stage, how many chromosomes
does it have in the sporophyte stage?
a. 4
c. 16
b. 8
d. 32
Figure 21-2
____ 13. Which structure in Figure 21-2 is analogous to a human fetus?
a. A
c. C
b. B
d. D
____ 14. Which structure in Figure 21-2 is analogous to a yolk in a chicken egg?
a. A
c. C
b. B
d. D
____ 15. Which structure in Figure 21-2 is analogous to an egg’s shell?
a. A
c. C
b. B
d. D
____ 16. Which is the latest characteristic to appear in the evolutionary divergence of plants from green algae?
a. seeds
c. vascular tissue
b. flowers
d. embryo protection
____ 17. An annual plant is an anthophyte that completes its life cycle in one year. Which of the following adaptations
would you expect to find in an anthophyte with such a short life cycle?
a. deep roots
c. many flowers
b. large leaves
d. low growth
____ 18. A plant that is characterized by steady vegetative growth after germination, producing seeds early the next
spring, and then dying, has which type of life cycle?
a. annual
c. vascular
b. biennial
d. perennial
____ 19. Which of the following were the first land plants to evolve seeds?
a. angiosperms
c. mosses
b. gymnosperms
d. ferns
____ 20. The mobile reproductive parts of all nonvascular seedless plants are
a. rhizoids.
b. cones.
c. spores.
d. epiphytes.
____ 21. In the alternation of generations, the haploid stage is generated by meiosis and the diploid stage is generated
by
a. mitosis.
c. seed production.
b. fertilization.
d. gametes.
____ 22. Which is the list of three nonvascular plant divisions?
a. Pterophyta, Bryophyta, Anthocerophyta
b. Bryophyta, Anthocerophyta, Hepaticophyta
c. Lycophyta, Anthocerophyta, Hepaticophyta
d. Bryophyta, Cycadophyta, Hepaticophyta
____ 23. The plants in which division can live as long as 2,000 years?
a. Cycadophyta
c. Anthophyta
b. Gnetophyta
d. Lycophyta
____ 24. Identify the correct descriptors of the flowering plants commonly called carrots.
a. biennial, eudicot, Anthophyta
b. perennial, eudicot, Ginkgophyta
c. annual, nonvacsular, Bryophyta
d. perennial, eudicot, Lycophyta
____ 25. Which category of life cycle is a plant that dies back to the junction between stem and root every year, and
then regrows every subsequent season to bloom again?
a. gametophyte
c. conifer
b. haploid
d. perennial
____ 26. Which statement best explains why a row of annual marigolds grows and blooms profusely every year?
a. Marigolds are really perennials.
b. The plants are reseeding themselves.
c. Marigolds have complex life cycles.
d. The plants are cross-breeding with perennials.
____ 27. Of the divisions of gymnosperms, which one might be chosen to use as wood for making wood carvings or
fine furniture?
a. Cycadophyta
c. Ginkgophyta
b. Gnetophyta
d. Coniferophyta
____ 28. Of the five divisions of vascular, seed-bearing plants, how many are gymnosperms?
a. two
c. four
b. three
d. five
____ 29. Seeds without fruit are produced by plants in Division
a. Coniferophyta
c. Anthophyta
b. Lycophyta
d. Pterophyta
____ 30. Gymnosperms, the naked-seeded plants, fall into the following four living divisions:
a. Cycadophyta, Gnetophyta, Ginkgophyta, Anthophyta
b. Pterophyta, Gnetophyta, Ginkgophyta, Coniferophyta
c. Pterophyta, Gnetophyta, Ginkgophyta, Anthophyta
d. Cycadophyta, Gnetophyta, Ginkgophyta, Coniferophyta
____ 31. With regard to the alternation of generations, how are lycophytes, or club mosses, similar to the seed-bearing
vascular plants?
a. They reproduce by mitosis.
b. In both, the sporophyte is dominant.
c. In both, the gametophyte is dominant.
d. Neither have alternation of generation life cycles.
____ 32. The sporophytes of ferns are similar to those of seed-bearing plants in that both
a. are independent forms.
c. are dependent on moisture.
b. live inside cones.
d. produce spores.
____ 33. A seedless vascular plant’s roots are analogous to which structures in a nonvascular plant?
a. cuticles
c. stems
b. sporangia
d. rhizoids
____ 34. In the process of the evolution of plants, liverworts appeared after green algae, but before seedless vascular
plants. With this information, predict where liverworts would most likely be found.
a. rocky coastlines
c. moist, shady places
b. the bottom of ponds
d. dry, grassy areas
____ 35. Which is the best explanation for why vascular plants can grow tall on land, and nonvascular plants remain
small and bound to water?
a. They occupy different niches to avoid competition.
b. Osmosis is a very slow transport system for water.
c. Vascular tissues are involved in their reproductive strategies.
d. Nutrient availability allows vascular plants to grow tall.
____ 36. A stem with tiny leaf-like extensions is characteristic of which division of nonvascular plants?
a. bryophytes
c. pterophytes
b. hepaticophytes
d. anthocerophytes
____ 37. You are given a nonvascular plant to identify as either a moss or a liverwort. Which characteristic is unique to
only one, and can help you identify the plant?
a. grows on a log or along a stream
b. has unicellular rhizoids
c. absorbs and transports water by osmosis
d. grows close to the ground
____ 38. Club mosses and ferns have unique characteristics that place them on a different branch of the evolutionary
tree from the bryophytes. Below are listed several characteristics of club mosses, ferns, and bryophytes.
Which two are characteristic of only club mosses and ferns?
1. have a form of embryo protection
2. low-growing in moist environments
3. have simple vascular systems
4. reproduce with spores
5. possess true roots and leaves
6. are the most primitive land plants
a. 1 and 2
b. 2 and 4
c. 3 and 5
d. 5 and 6
____ 39. Which of the evolved characteristics below is not an evolutionary milestone first observed in club mosses and
ferns?
a.
b.
c.
d.
strobila for spore dispersal by the wind
vascular tissue for water and nutrient uptake
vascular components for growth support to compete for sunlight
stomata for gas exchange and to retard dessication by closing the cuticle opening
Figure 22-1
____ 40. Which structure shown in Figure 22-1 is not found in animal cells?
a. A
c. D
b. C
d. F
Figure 22-2
____ 41. Which picture shown in Figure 22-2 is the most likely outcome?
a. A
c. C
b. B
d. D
____ 42. Which of the following tissues would limit the rate of transpiration the most?
a. cuticle
c. trichomes
b. phloem
d. xylem
____ 43. An experiment is designed to test the following hypothesis: The rate of transpiration will increase with air
humidity. What do you think the conclusion of the experiment will be?
a. The hypothesis is correct because high humidity would promote transpiration.
b. The hypothesis is incorrect because high humidity would most likely inhibit transpiration.
c. The hypothesis is correct because roots are able to absorb more moisture during humid
weather.
d. The hypothesis is incorrect because there is no relationship between air humidity and
transpiration.
____ 44. A plant cell’s cytoplasm increases in acidity. Which of the following hormones is most likely acting on the
cell?
a. auxin
c. ethylene
b. cytokinins
d. gibberellins
____ 45. A nursery manager wants to grow a dwarf variety of lemon trees using the seedlings of regular lemon trees.
She sprays the seedlings with a chemical that inhibits gibberellins. Evaluate her decision.
a. To produce a dwarf plant, she should attempt to inhibit both the cytokinins and auxins.
b. Dwarf plants often lack gibberellins, so the spray will most likely work as planned.
c. It would be more effective if she sprayed the seedlings with a chemical that inhibits auxin.
d. Rather than inhibiting gibberellins, she should spray the seedlings with synthetic
gibberellins.
____ 46. Which of the following hormones does not affect plant growth?
a. auxin
c. ethylene
b. cytokinins
d. gibberellins
____ 47. Evaluate the common expression, “One rotten apple spoils the whole barrel.”
a. The expression is true because all of the apples most likely came from the same tree.
b. The expression is false because one apple cannot affect the freshness of another apple.
c. The expression is false because cytokinins would protect the cellular integrity of the cells
in the other apples.
d. The expression is true because a rotting apple gives off ethylene, which would speed the
ripening of the other apple.
____ 48. The stems of a plant growing out of the side of a cliff will grow upward because of
a. gravitropism.
c. phototropism.
b. photoperiodism.
d. thigmotropism.
____ 49. Changes in the shapes of guard cells result in the opening and closing of stomata. Which of the following
ideas would most likely explain how a guard cell can change its shape?
a. Heat causes the guard cell to expand or contract.
b. Water moving into and out of the guard cell causes it to swell or shrink.
c. The cuticle around the guard cell thickens when auxin binds with the cell’s hormone
receptors.
d. Sugar crystals in the walls of the guard cells can move from a pentagonal shape to a
hexagonal shape.
____ 50. A scientist has invented a plant fertilizer that promotes the growth of collenchyma cells. What would be the
most appropriate time for a gardener to use this fertilizer?
a. during the winter
b. if the plant is injured
c. when the plant is a seedling
d. if the plant loses too many leaves
____ 51. Sagebrush grows in regions that receive little annual precipitation. Which type of root structure would a
sagebrush most likely have?
a. adventitious
c. pneumatophores
b. fibrous
d. taproot
____ 52. The api-api putih shrub grows in swamps in western India. What type of root system does it most likely have?
a. adventitious
c. pneumatophores
b. fibrous
d. taproot
____ 53. Based on your knowledge of stem structure in a plant, why will removing the bark of a tree kill the tree?
a. Removing the bark removes phloem, preventing nutrient movement to the roots.
b. Removing the bark removes cambium and prevents further growth of the tree.
c. Removing the bark allows pathogens into the sensitive tissues beneath.
d. Removing the bark destroys the ability of the tree to draw water from the ground.
____ 54. Why do plants grown in a heated greenhouse in winter rarely grow as fast as the same type of plant grown
outside during the summer?
a. There is less solar energy available during the winter.
b. Most plants can only grow in a very narrow temperature range.
c. Greenhouse plants don’t get the same nutrients as plants growing in the ground.
d. Plants go through growing cycles whether the environment is conducive towards growth
or not.
____ 55. How could you increase the bushiness of a plant?
a. Trim the plant’s apical meristems.
b. Trim the plant’s lateral meristems.
c. Trim the plant’s intercalary meristems.
d. Trim the plant’s cork cambium meristems.
____ 56. Which of the following cells are part of a plant’s dermal tissue?
a. ground cells and collenchyma cells
b. sieve-tube members and companion cells
c. tracheid cells and parenchyma cells
d. trichome cells and guard cells
____ 57. A researcher notices that the cells of the stem have elongated in a plant she is observing. Which hormone(s)
might cause this to occur?
a. auxin only
c. auxin and gibberellins
b. gibberellins only
d. cytokinins and gibberellins
____ 58. Which of the following plant hormones would not be found in a growing seedling?
a. auxin
c. ethylene
b. cytokinins
d. gibberellins
____ 59. A scientist does a chemical analysis of a wilted flower that just dropped from a plant. Which hormone would
most likely be found in the flower?
a. auxin
c. ethylene
b. cytokinins
d. gibberellins
____ 60. Which function do stems and roots share?
a. transpiration
b. photosynthesis
c. support of the plant body
d. intake of water and nutrients
____ 61. The cells of the root cap produce a slimy substance to
a. attract water molecules.
b. soften up the soil around the root.
c. reduce friction between the growing root and the soil.
d. fixate nitrogen gas in the soil before it is absorbed by the roots.
____ 62. A potted plant is tipped on its side. Within a few days, the plant stem bends upward by around 90 degrees.
Which hormone is most likely responsible for this change?
a. auxin
c. cytokinins
b. ethylene
d. gibberellins
____ 63. Which of the following hypotheses about plant responses is most likely true?
a. Trees do not experience the plant response thigmotropism.
b. The growth of plant roots is affected by the movement of the moon.
c. A change in air temperature will cause a tropic response in deciduous plants.
d. Plants in tropical areas experience faster growth rates than plants in temperate areas.
____ 64. How does the spacing of the cells in the spongy mesophyll aid in a leaf’s function?
a. The loosely packed cells allow the leaf to be flexible so that the leaf can bend in the wind.
b. The tightly packed cells have a large surface area in which light energy can be collected.
c. The loosely packed cells allow ingredients used for photosynthesis to move readily
through the leaf.
d. The tightly packed cells form a barrier from the exterior environment and protect the leaf
from diseases and predators.
____ 65. A bud appears on a tree in the spring. What type of tissue is the majority of the bud composed of?
a. dermal
c. meristematic
b. ground
d. vascular
____ 66. What is the most likely seed-dispersal mechanism for a coconut?
a. catch in animal fur
c. water
b. eaten by animals
d. wind
Figure 23-1
____ 67. What is the purpose of A and B in Figure 23-3?
a. asexual reproduction
c. sexual reproduction
b. protection
d. transpiration
____ 68. What is it called when new plants grow from parts of an existing plant?
a. binary fission
c. transplanting
b. sexual reproduction
____ 69. What does the fertilization of an egg form?
a. flowers
b. sperm
d. vegetative reproduction
c. sporophytes
d. zygote
____ 70. Which of the following is true of flowering plants?
a. the sporophytes depend on the gametophyte for support
b. the sporophytes depend on the gametophyte for food
c. the sporophyte lives independently of the gametophyte
d. the gametophyte lives independently of the sporophyte
____ 71. The prothallus is part of the life cycle of which group of plants?
a. angiosperms
c. ferns
b. conifers
d. mosses
____ 72. Conifers produce two types of spores that develop into male or female gametophytes; because of this, what
term is applied to conifers?
a. heterosporous
c. incomplete
b. coniferous
d. prothallus
____ 73. What is the opening to the ovule of a conifer called?
a. heterosporous
c. micropyle
b. megaspore
d. microspore
____ 74. What is the underground stem that produces roots in a fern called?
a. archegonium
c. prothallus
b. frond
d. rhizome
Figure 23-2
____ 75. A diagram of a flower is included here. Which of the following letters corresponds to the male reproductive
organs of a plant?
a. A
c. C
b. B
d. D
____ 76. What is the female reproductive structure of a flower called?
a. petal
c. sepal
b. pistil
d. stamen
____ 77. What type of flower has either functioning stamens or functioning pistils?
a. complete
c. heterosporous
b. imperfect
d. perfect
____ 78. Which type of flower has flower organs in multiples of three?
a. dicot
c. monocot
b. eudicot
d. perfect
____ 79. Flowers that produce large amounts of lightweight pollen are usually best suited for which type of
pollination?
a. insect pollination
c. self pollination
b. bird pollination
d. wind pollination
____ 80. Plants that thrive in tropical regions are most likely what type of plants?
a. day-neutral plants
c. long-day plants
b. intermediate-day plants
d. short-day plants
____ 81. What is a plant that flowers over a range of daylight hours called?
a. day-neutral plant
c. long-day plant
b. intermediate-day plant
d. short-day plant
____ 82. Which of the following is actually a more accurate name for a short-day plant?
a. day-neutral plant
c. long-night plant
b. long-day plant
d. short-night plant
____ 83. When is a microspore a pollen grain?
a. when it is a female gameotphyte
b. when it is a female sporophyte
c. when it is a male gametophyte
d. when it is a male sporophyte
____ 84. Which term best describes fertilization in an anthophyte egg?
a. double fertilization
c. natural fertilization
b. facilitated fertilization
d. single fertilization
____ 85. Strawberries are examples of what kind of fruit?
a. aggregate fruit
c. multiple fruit
b. dry fruit
d. simple fruit
____ 86. What is the name for the process that occurs when the embryo in a seed starts to grow?
a. allelopathy
c. germination
b. dispersal
d. hypocotyl
____ 87. If a seed is produced at the end of the growing season, which state do they usually enter?
a. dispersal
c. germination
b. dormancy
d. hypocotyl
____ 88. When can photosynthesis begin in a plant?
a. after germination
b. when the hypocotyl breaks to the surface
c. when cells with chloroplasts appear above ground
d. when the radicle appears from the seed
____ 89. What determines the length of the pollen tube?
a. cotyledon
c. pollen grain
b. pistil
d. stamen
____ 90. Which of the following provides nourishment for the plant embryo?
a. seed coat
c. endosperm
b. egg
d. sperm
Problem (10 points each) Need to be thorough with responses.
91. Draw a simple diagram that illustrates the path of water through a plant.
Figure 23-4
92. A plant located near 35° north latitude flowers on the day indicated by the arrow in Figure 23-4. Classify this
plant according to its photoperiodic response, describe its critical period, and explain your answers.
Essay (20 points each) Need to be very thorough in answering these questions.
93. A television special called The History of Earth presents information about the formation of Earth and early
environmental conditions on the planet. During the presentation, the narrator explains that early Earth’s
atmosphere did not contain free oxygen and free oxygen was added to the atmosphere after plants evolved and
colonized the land. Use what you know about cellular biology and plant cells to write a short essay that
assesses the validity of this statement.
94. Describe the life cycles of the mosses, ferns, and conifers with particular attention to the evolutionary
transition in dominant generations.
Plants Chaps 21-23
Answer Section
TRUE/FALSE
1. ANS: T
This is one of the characteristics shared by present-day plants.
PTS: 1
DIF: Bloom's Level A
REF: 604
TOP: 21-1
2. ANS: T
Male gymnosperms release clouds of pollen that are incompatible with pollen allergies.
PTS: 1
DIF: Bloom's Level C
REF: 618–619
TOP: 21-11
3. ANS: F
The opposite is true, more recent plant groups have a dominant sporophyte, while more ancient groups have a
dominant gametophyte plant.
PTS: 1
DIF: Bloom's Level B
REF: 607
TOP: 21-4
4. ANS: F
Tropical rain forest plants have leaves with many stomata. Leaves of plants in colder, drier regions have fewer
stomata.
PTS: 1
DIF: Bloom's Level C
REF: 636
NAT: LS_5d
TOP: 22-2
5. ANS: T
If the stomata close, carbon dioxide will not be able to enter the plant. This would inhibit photosynthesis.
PTS: 1
DIF: Bloom's Level E
REF: 636
NAT: LS_1e
TOP: 22-3
6. ANS: T
Meristematic tissues make up meristems, which are areas of rapidly dividing cells.
PTS: 1
DIF: Bloom's Level B
REF: 634
TOP: 22-3
7. ANS: F
Mosses are nonvascular plants and exhibit alteration of generations.
PTS: 1
DIF: Bloom's Level B
REF: 664
TOP: 23-3
8. ANS: T
The plant’s stamen-containing, or male, flowers release pollen grains.
PTS: 1
TOP: 23-4
9. ANS: F
DIF: Bloom's Level C
REF: 671
In anthophytes, the sporophyte generation is dominant and supports the gametophyte generation.
PTS: 1
DIF: Bloom's Level C
TOP: 23-9
10. ANS: F
The tube nucleus directs the growth of the pollen tube.
PTS: 1
TOP: 23-10
DIF: Bloom's Level B
REF: 674
REF: 675
MULTIPLE CHOICE
11. ANS: A
The food energy for the plant is produced by photosynthesis in the leaves.
Feedback
A
B
C
D
That's right!
The branches do not produce food for the plant.
The trunk functions in support and transport.
The roots supply water, nutrients, and support for the plant.
PTS: 1
DIF: Bloom's Level A
NAT: LS_1e
TOP: 21-2
12. ANS: D
The gametophyte is haploid, while the sporophyte is diploid.
REF: 606
Feedback
A
B
C
D
This is too few chromosomes.
Is the gametophyte diploid or haploid?
Review page 607.
That's right!
PTS: 1
DIF: Bloom's Level B
NAT: LS_2b
TOP: 21-3
13. ANS: C
The embryo of the seed is analogous to the human fetus.
REF: 607
Feedback
A
B
C
D
This is not the embryo.
This is not a living part of the seed.
That's right!
Have a look at page 607.
PTS: 1
DIF: Bloom's Level D
REF: 607
TOP: 21-2
14. ANS: A
The yolk of an egg, like the structure indicated by A, provides nutrients to the developing embryo.
Feedback
A
B
C
D
That's right!
This structure does not contain nutrients.
Have a look at page 607 for more information.
This structure does not provide nutrients to the embryo.
PTS: 1
DIF: Bloom's Level D
REF: 607
TOP: 21-2
15. ANS: B
The seed coat protects the seed like the eggshell protects an egg.
Feedback
A
B
C
D
Where is the shell of an egg located?
That's right!
This is inside, not outside, the seed.
Have a look on page 607.
PTS: 1
DIF: Bloom's Level D
REF: 607
TOP: 21-2
16. ANS: B
Divergent characteristics appeared in the following order: embryo protection, vascular tissue, seeds, flowers
Feedback
A
B
C
D
Seeds can be produced by plants with no flowers.
Right!
Vascular tissue came earlier than seeds.
Embryo protection is the earliest of all—not the latest. Try again.
PTS: 1
DIF: Bloom's Level D
REF: 604
NAT: LS_3d
TOP: 21-1
17. ANS: C
Annuals are abundant flower producers so they may produce as many seeds as possible before the end of their
one-year life span.
Feedback
A
B
C
D
Deep roots are not unique to annual plants.
Large leaves are adaptations for gathering sunlight. Try again.
Yes!
Low growth is an adaptation for obtaining moisture.
PTS: 1
DIF: Bloom's Level D
TOP: 21-12
18. ANS: B
Biennials live out their life span in two growing seasons.
REF: 621
Feedback
A
B
C
D
Refer to page 621.
Correct.
This answer choice does not describe a life span, but rather a structure.
These plants live several years.
PTS: 1
DIF: Bloom's Level D
REF: 621
TOP: 21-12
19. ANS: B
Gymnosperms were the first plants, land or water, to reproduce with seeds and not spores.
Feedback
A
B
C
D
See page 617 for more information.
This is the correct choice.
Mosses reproduce with spores.
Ferns make spores, not seeds.
PTS: 1
DIF: Bloom's Level D
REF: 617
TOP: 21-11
20. ANS: C
Cones are reproductive parts, but not considered mobile. Spores are reproductive parts that are mobile.
Feedback
A
B
C
D
Review the structures of nonvascular plants.
Review the structures of vascular seedless plants.
Correct.
Epiphytes are a type of plant, not a reproductive structure.
PTS: 1
DIF: Bloom's Level D
REF: 610
TOP: 21-6
21. ANS: B
When two haploid gametes fuse, the event is fertilization and a diploid organism results.
Feedback
A
B
C
D
Review alternation of generations. Both stages undergo mitosis.
Yes!
The diploid sporophyte produces seeds.
Gametes are the resulting haploid structures.
PTS: 1
DIF: Bloom's Level D
REF: 607
NAT: LS_2b
TOP: 21-4
22. ANS: B
These are the three divisions of nonvascular plants: mosses, hornworts, and liverworts.
Feedback
A
B
C
D
Pterophytes are ferns, vascular plants.
That's right!
Lycophytes are clubmosses, vascular plants.
Cycadophytes are cycads, vascular plants.
PTS: 1
DIF: Bloom's Level B
REF: 609
NAT: LS_3e
TOP: 21-5
23. ANS: B
Because of unusual structural adaptations, Gnetophyta are very long lived.
Feedback
A
B
C
D
Cycads are old evolutionarily, but not in individual life spans.
Correct.
Most flowering plants are annuals.
Try again.
PTS: 1
DIF: Bloom's Level D
REF: 609
TOP: 21-5
24. ANS: A
Carrots are biennial, flowering in the second season, then dying. They are anthophytes.
Feedback
A
B
C
D
Correct.
None of these descriptors go together.
Bryophytes cannot be described as annual.
Review beginning on page 609.
PTS: 1
DIF: Bloom's Level D
REF: 609
TOP: 21.5
25. ANS: D
Perennials are anthophytes that have very long life spans—three or more years at a minimum. Examples of
perennial anthophytes in this case are iris, chrysanthemums, and phlox.
Feedback
A
B
C
D
This word identifies a stage in the alternation of generations.
This word describes the number of chromosomes in a gamete.
This is a type of seedless vascular plant.
Correct.
PTS: 1
DIF: Bloom's Level E
REF: 621
TOP: 21-12
26. ANS: B
Annuals grow, develop, bloom, and make seeds in one season, which is what marigolds do. Some seeds are
disbursed, and some fall where the parent plant bloomed, making it seem as though the same plant is living
forever. The parent plant dies, and the seedlings take its place.
Feedback
A
B
C
D
The question states that marigolds are annuals.
This is correct!
Yes, but this does not explain the year-after-year survival of annuals.
Not possible. Try again.
PTS: 1
DIF: Bloom's Level E
REF: 621
TOP: 21-12
27. ANS: D
Coniferophyta includes pines, cypress, and redwoods, all of which make beautiful, finished wood. This
division contains the only gymnosperms with long woody stems suitable for woodworking.
Feedback
A
B
C
D
Cycads produce herbaceous stems.
Review page 619.
Ginkgos are valued for their ornamental features, but not for woodworking.
That's right!
PTS: 1
DIF: Bloom's Level E
REF: 619
TOP: 21-11
28. ANS: C
Cycadophyta, Gnetophyta, Ginkgophyta, and Coniferophyta are gymnosperms bearing naked seeds.
Anthophyta are angiosperms and bear seeds inside fruits.
Feedback
A
B
C
D
Review seed-bearing vascular plant divisions.
Close, but not correct.
Correct.
Anthophyta is not a gymnosperm.
PTS: 1
DIF: Bloom's Level E
REF: 618–619
NAT: LS_3e
TOP: 21-11
29. ANS: A
Conifers produce “naked seeds.” Conifers are gymnosperms, which means “naked seed.” Naked seeds mean
“without fruit.”
Feedback
A
B
C
D
Right!
These don't produce seeds at all.
These produce seeds with fruit.
These produce spores.
PTS: 1
DIF: Bloom's Level E
TOP: 21-10
30. ANS: D
These are the four naked-seeded divisions.
REF: 618–619
Feedback
A
B
C
D
Anthophytes have fruits; the seeds are not naked.
Pterophytes do not have seeds.
Pterophytes do not have seeds.
That's right!
PTS: 1
DIF: Bloom's Level B
REF: 618–620
NAT: LS_3e
TOP: 21-11
31. ANS: B
Club mosses, which are seedless vascular plants, are unlike the true mosses in that the sporophyte is dominant
as with seed-bearing vascular plants.
Feedback
A
Review reproduction in alternation of generations on page 607.
B
C
D
This is correct.
Try again.
No, both do.
PTS: 1
DIF: Bloom's Level E
REF: 613
TOP: 21-8
32. ANS: D
Both produce spores. Seed plants are not dependent on moisture, some do not live inside cones, and are not all
independent forms.
Feedback
A
B
C
D
Review the life cycle of ferns.
Not all seeds live inside cones.
The development of seeds made plants relatively independent of moisture for
reproduction.
Right!
PTS: 1
DIF: Bloom's Level E
REF: 615 | 617
TOP: 21-8
33. ANS: D
Roots are analogous structures to a nonvascular plant’s rhizoids.
Feedback
A
B
C
D
Cuticles perform a different function altogether.
Sporangia are reproductive structures.
Stems and roots are different structures.
Right!
PTS: 1
DIF: Bloom's Level D
REF: 606
TOP: 21-8
34. ANS: C
Lacking vascular tissue, liverworts require close contact with moisture. They do not tolerate dessicating
salinity, or anaerobic areas, such as coastlines or the bottom of ponds.
Feedback
A
B
C
D
Too much salinity.
Not enough oxygen.
Right again!
Not enough moisture.
PTS: 1
DIF: Bloom's Level E
REF: 606
TOP: 21-3
35. ANS: B
Nonvascular plants transport water and nutrients by osmosis and diffusion. Vascular plants evolved a more
effective transport strategy that produced tall land plants.
Feedback
A
B
This may be a true statement, but it does not answer the question.
This is it!
C
D
Review reproductive strategies in vascular and nonvascular plants.
Not true. Try again.
PTS: 1
DIF: Bloom's Level E
REF: 606
TOP: 21-3
36. ANS: A
This form of plant body is characteristic of the moss gametophyte, or the division Bryophyta.
Feedback
A
B
C
D
That's right!
Liverworts have a flattened, broad thallus.
Pterophytes, or ferns, are vascular plants.
Hornworts have a thallus-like gametophyte and the horn-like sporophyte.
PTS: 1
DIF: Bloom's Level C
REF: 610–612
TOP: 21-7
37. ANS: B
A, C, and D are common to mosses and liverworts. Mosses, however, have multicellular rhizoids, so the
unicellular rhizoids are the identifying factor. The plant is a liverwort.
Feedback
A
B
C
D
Both can live here.
Right!
Both do this.
Both grow low to the ground.
PTS: 1
DIF: Bloom's Level D
REF: 610 | 612
TOP: 21-7
38. ANS: C
Nonvascular bryophytes do not possess characteristics 3 and 5. Seedless vascular club mosses and ferns
possess all but characteristic 6, which describes liverworts.
Feedback
A
B
C
D
Both of these are characteristic of bryophytes and most club mosses and some ferns.
This is characteristic of all the organisms, not unique to club mosses and ferns.
Right!
One is true of bryophytes, and one is true of club mosses and ferns.
PTS: 1
DIF: Bloom's Level F
REF: 613
TOP: 21-9
39. ANS: D
Stomata are an evolutionary milestone for all land-dwelling plants, first observed in nonvascular plants. All
other characteristics are first observed in club mosses and ferns.
Feedback
A
B
C
Be sure you understand the question.
This is a characteristic of club mosses and ferns. The question wants to know which is
NOT a characteristic.
Review the evolutionary trees included at the beginning of each section.
D
Correct. This adaptation appeared with the first land plants.
PTS: 1
TOP: 21-9
40. ANS: A
DIF: Bloom's Level F
REF: 606 | 613–616
Feedback
A
B
C
D
Great job!
Check back at the diagram again.
Do you need a little more help? Check back at page 632.
Close but not quite.
PTS: 1
NAT: LS_1a
41. ANS: B
DIF: Bloom's Level B
TOP: 22-1
REF: 632
Feedback
A
B
C
D
No, this isn’t quite right.
Yes, you are right. The plant would move toward the light.
Do you really think the plant would move away from the light?
Check back at page 651 if you need a little more help.
PTS: 1
DIF: Bloom's Level B
REF: 651
NAT: LS_6b
TOP: 22-8
42. ANS: A
The waxy cuticle limits transpiration. Xylem does carry water through a plant, but it does not affect how
quickly transpiration occurs.
Feedback
A
B
C
D
That's correct!
What is carried by phloem?
Where does the water go after it moves through the xylem?
Refer to page 636.
PTS: 1
DIF: Bloom's Level D
REF: 636–637 | 645
NAT: LS_5d
TOP: 22-3
43. ANS: B
The transpiration rate in plants increases during low humidity as water evaporates more quickly from plant
leaves, causing water to move more quickly up the vascular tissues.
Feedback
A
B
C
D
Think about the relationship between transpiration and evaporation rates.
That's correct!
Water absorption at the roots is affected by soil moisture, not air moisture.
Did you consider all the factors?
PTS: 1
TOP: 22-5
44. ANS: A
DIF: Bloom's Level F
REF: 645
Auxin promotes a flow of hydrogen ions through proton pumps from the cytoplasm into the cell wall. This
creates a more acidic environment, which weakens the connections between the cellulose fibers in the cell
wall.
Feedback
A
B
C
D
That's correct!
.Increased acidity helps a cell elongate, but cytokinin helps it divide more rapidly.
You're on the right track
Try again.
PTS: 1
DIF: Bloom's Level C
REF: 648–650
NAT: LS_5d
TOP: 22-6
45. ANS: B
Dwarf plants are characterized by their short height. The hormone that most affects a plant’s height is
gibberellins, so inhibiting gibberellins will produce a shorter plant.
Feedback
A
B
C
D
Cytokinins affect the rate of cell division, not plant height.
That's correct!
Refer to page 648 for more information.
More gibberellins would increase plant height.
PTS: 1
DIF: Bloom's Level F
NAT: LS_5d
TOP: 22-6
46. ANS: C
Ethylene’s primary effect is the ripening of fruits.
REF: 648–650
Feedback
A
B
C
D
Refer to page 648 for more information.
Refer to page 650 for more information.
That's correct!
Refer to page 649 for more information.
PTS: 1
DIF: Bloom's Level B
REF: 648–650
NAT: LS_5d
TOP: 22-6
47. ANS: D
This expression is derived from the observations of fruit growers and vendors. The ethylene that caused a fruit
to ripen would escape as the fruit began to rot. Fungi and bacteria feeding off the rotten fruit would also be
transferred to nearby fruit.
Feedback
A
B
C
D
This assumption cannot be made.
Did you consider all the factors?
Cytokinins cannot stop a fruit from ripening.
That's correct!
PTS: 1
NAT: LS_5d
48. ANS: A
DIF: Bloom's Level F
TOP: 22-6
REF: 648–650
Gravitropism is the response of a plant to gravity.
Feedback
A
B
C
D
That's correct!
Photoperiodism is the response of a plant to the length of days and nights.
Phototropism is the response of a plant to light.
Thigmotropism is the response of a plant to touch.
PTS: 1
DIF: Bloom's Level C
REF: 651
NAT: LS_6b
TOP: 22-8
49. ANS: B
Water moves into a guard cell, causing it to swell. If both guard cells around a stoma are swollen, the stoma is
open. If the water moves out of the cells, the cells shrink and the stoma closes.
Feedback
A
B
C
D
The cells do expand and contract, but not because of heat.
That's correct!
A plant's cuticle does not affect the shape of its cells.
Cell walls are not composed of sugar crystals.
PTS: 1
DIF: Bloom's Level F
REF: 636
NAT: LS_5d
TOP: 22-1
50. ANS: B
Collenchyma cells help to repair and replace damaged tissues. Therefore, the fertilizer would be most useful if
it was applied to a damaged plant.
Feedback
A
B
C
D
Many fertilizers should not be applied when the plant is dormant.
That's correct!
Did you consider all the factors?
A plant without enough leaves needs more parenchyma cells rather than collenchyma
cells.
PTS: 1
DIF: Bloom's Level E
TOP: 22-1
51. ANS: D
Taproots grow deep into the soil toward available water.
REF: 633
Feedback
A
B
C
D
Refer to page 641 for more information.
Are you considering all the factors?
Pneumatophores are found in plants that live in marsh-like environments.
That's correct!
PTS: 1
DIF: Bloom's Level D
REF: 641
NAT: LS_5d
TOP: 22-5
52. ANS: C
The api-api putih can grow to be a shrub or tree. Like other plants that live in water, it has pneumatophores
that help supply oxygen to the roots.
Feedback
A
B
C
D
Adventitious roots are common in very tall plants.
Did you consider all the factors?
That's correct!
Did you consider all the factors?
PTS: 1
DIF: Bloom's Level D
REF: 641
NAT: LS_5d
TOP: 22-5
53. ANS: A
Bark consists of cork, cork cambium, and phloem. Phloem is the vascular tissue that transports sugars
throughout the plant. When phloem is removed, especially from the entire circumference of a tree trunk, the
tree can no longer transport nutrients to and from the roots.
Feedback
A
B
C
D
That's correct!
This is true, but it would not directly lead to the death of the tree.
The tissues under the bark are actually not alive.
Xylem tissue (in the "wood" of the tree) transports water.
PTS: 1
DIF: Bloom's Level F
REF: 638 | 642
TOP: 22-5
54. ANS: A
For plants to grow, they need nutrients and energy. Plant energy comes from photosynthesis, and the rate of
photosynthesis depends on the amount of solar energy that reaches the plants leaves.
Feedback
A
B
C
D
That's correct!
Check back at page 644 if you are having trouble.
Nutrients can be artificially provided to a plant.
Plant growth is controlled by hormones that are not released in set cycles.
PTS: 1
DIF: Bloom's Level E
REF: 644
NAT: LS_1e
TOP: 22-4
55. ANS: A
Auxin produced by apical meristems inhibit the growth of lateral meristems. If you remove the apical
meristems, you promote the growth of the lateral meristems, causing the plant to be bushy.
Feedback
A
B
C
D
That's correct
Consider the affects of hormones on plant growth.
Refer to page 634 for more information.
Cork cambium is a type of lateral meristem.
PTS: 1
DIF: Bloom's Level E
REF: 634 | 649
TOP: 22-7
56. ANS: D
A plant’s epidermis include guard cells as well as other types of cells such as trichome cells.
Feedback
A
B
C
D
Review the different types of plant cells discussed in Section 22.1.
These cells are found in phloem.
Tracheid cells are found in xylem.
That's correct!
PTS: 1
DIF: Bloom's Level D
REF: 636
TOP: 22-1
57. ANS: C
Both auxin and gibberellins are capable of causing cell elongation.
Feedback
A
B
C
D
You're on the right track.
Try again.
That's correct!
Cytokinin typically causes cell division.
PTS: 1
DIF: Bloom's Level C
REF: 648–649
NAT: LS_5d
TOP: 22-7
58. ANS: C
Ethylene mainly acts on a plant during its reproductive cycle, causing fruits to ripen and flower structures to
die.
Feedback
A
B
C
D
Auxin is found in rapidly growing plant tissues.
Cytokinins are produced in rapidly dividing cells.
That's correct!
Gibberellins affect seed growth.
PTS: 1
DIF: Bloom's Level E
REF: 648–650
NAT: LS_5d
TOP: 22-6
59. ANS: C
Ethylene is found in plant tissues such as ripening fruits, dying leaves, and flowers.
Feedback
A
B
C
D
Refer to page 649 for more information.
Try again.
That's correct!
Did you consider all the factors?
PTS: 1
DIF: Bloom's Level D
REF: 649
NAT: LS_5d
TOP: 22-6
60. ANS: C
The roots anchor the plant in the ground, and the stem supports the leaf structures.
Feedback
A
B
C
Transpiration occurs in leaves.
Photosynthesis does not take place in roots.
That's correct!
D
Did you consider all the factors?
PTS: 1
DIF: Bloom's Level D
REF: 639 | 642
TOP: 22-5
61. ANS: C
The slimy substance produced by root cap cells helps lubricate the root as it grows through the soil.
Feedback
A
B
C
D
Refer to page 639 for more information.
You are getting close.
That's correct!
Bacteria and other microorganisms in the soil work to fixate nitrogen.
PTS: 1
DIF: Bloom's Level B
REF: 639
TOP: 22-4
62. ANS: A
Unequal distribution of auxin inside a plant cell can cause the cell to elongate on one end and shrink on the
other end. If this occurs in stem cells, it will result in a bent stem.
Feedback
A
B
C
D
That's correct!
Try again.
You're on the right track.
Did you consider all the factors?
PTS: 1
DIF: Bloom's Level E
REF: 648–649 | 651
NAT: LS_5d
TOP: 22-6
63. ANS: B
Roots have tropic responses to gravity. The moon’s gravity affects many processes on Earth, including plant
growth. The lunar cycle causes the acceleration or slowing the growth of plant roots depending on the
position of the moon.
Feedback
A
B
C
D
Trees exhibit thigomotropism when they grow in the direction that wind is blowing.
That's correct!
A change in air temperature can cause a nastic response, not a tropic response.
Often, plants in cooler regions grow faster than plants in tropical regions. This is an
adaptation to help plants reproduce during the shorter growing season that occurs in a
cool region.
PTS: 1
DIF: Bloom's Level F
REF: 651
NAT: LS_6b
TOP: 22-8
64. ANS: C
The cells of the spongy mesophyll are irregularly-shaped and loosely packed. Oxygen, carbon dioxide, and
water vapor are able to easily move through the spaces between the cells of the spongy mesophyll.
Feedback
A
B
Flexibility is not a primary leaf function.
You're on the right track.
C
D
That's correct!
This is the job of the epidermis.
PTS: 1
DIF: Bloom's Level B
REF: 644
NAT: LS_5d
TOP: 22-4
65. ANS: C
Buds are growth regions composed mostly of meristematic tissue.
Feedback
A
B
C
D
Refer to page 634 for more information.
Most of an adult plant is composed of ground tissue.
That's correct!
Did you consider all the factors?
PTS: 1
DIF: Bloom's Level D
REF: 634
TOP: 22-2
66. ANS: C
Seeds can be dispersed in different ways. Some are inside spiny fruits that attach to animal fur. Some are in
fruit that are eaten by birds. Some travel on the wind. A seed like a coconut is too big for these methods and
will float.
Feedback
A
B
C
D
Hold on. Remember that a coconut seed is rather large.
Check back at page 671 for more help.
Exactly!
Try again.
PTS: 1
DIF: Bloom's Level B
REF: 671
TOP: 23-7
67. ANS: B
Sepals cover and protect the flower bud. Petals protect the stigma and anther and attract pollinators.
Feedback
A
B
C
D
Not this one. Try again.
Very good!
This is not true of plants.
Not a bad guess but this is not correct.
PTS: 1
DIF: Bloom's Level A
REF: 668
TOP: 23-4
68. ANS: D
Vegetative reproduction is a specific type of asexual reproduction that takes place in plants.
Feedback
A
B
C
D
This occurs in bacteria.
Look back at page 662 if you are having trouble.
This is something gardeners do.
You’ve got it!
PTS: 1
DIF: Bloom's Level C
TOP: 23-1
69. ANS: D
The fertilization of an egg, in a plant or animal, forms a zygote.
REF: 662
Feedback
A
B
C
D
Not this one. Flowers have a different purpose in a plant.
Having trouble? Re-read page 663.
Try again.
Very good!
PTS: 1
DIF: Bloom's Level A
REF: 663
NAT: LS_2b
TOP: 23-2
70. ANS: C
In flowering plants the sporophyte is an independent plant body.
Feedback
A
B
C
D
Sorry. This answer is incorrect.
Be careful. This is backwards.
Very good!
This is only partly true in the case of pollen.
PTS: 1
DIF: Bloom's Level D
TOP: 23-2
71. ANS: C
Ferns have a prothallus in their life cycle.
REF: 663
Feedback
A
B
C
D
Check back at page 665 if you are having trouble.
Sorry. Try again.
That’s correct!
Mosses have protonema, not a prothallus.
PTS: 1
DIF: Bloom's Level D
REF: 665
TOP: 23-3
72. ANS: A
Recall that the prefix hetero- means different. So it would follow that a cone that could develop into male or
female gametophytes would be heterosporous.
Feedback
A
B
C
D
Good job!
This just means they bear cones.
This applies to some flowering plants.
Check page 665 if you are having trouble.
PTS: 1
DIF: Bloom's Level C
TOP: 23-3
73. ANS: C
The opening to the ovule is called the micropyle.
REF: 665
Feedback
A
B
C
D
Check page 666 for more help.
These are cells.
Good!
Try again.
PTS: 1
DIF: Bloom's Level B
TOP: 23-3
74. ANS: D
Ferns have rhizomes under ground and fronds above ground.
REF: 666
Feedback
A
B
C
D
Not this one. Try again.
This is the “leafy” part of a fern.
You are on the right track. Try again.
Good job!
PTS: 1
DIF: Bloom's Level B
TOP: 23-3
75. ANS: D
The male reproductive organ in a plant is the stamen.
REF: 665
Feedback
A
B
C
D
Look again. This is something different.
No, this is the part of the flower that gives it the color.
Check page 668 if you need more help.
Yes!
PTS: 1
DIF: Bloom's Level B
TOP: 23-4
76. ANS: B
The female reproductive organ in a plant is the pistil.
REF: 668
Feedback
A
B
C
D
Check the diagram on page 668 for more help.
Great job!
This structure isn't involved in reproduction.
Think again.
PTS: 1
DIF: Bloom's Level B
REF: 668
TOP: 23-4
77. ANS: B
Recall that there are incomplete, complete, imperfect, and perfect flowers. An imperfect flower has either
functioning stamens or functioning pistils.
Feedback
A
B
Be careful. This is not a complete flower.
Way to go! You got it right.
C
D
Check back at page 669 if you are having trouble.
This one has both.
PTS: 1
DIF: Bloom's Level C
REF: 669
TOP: 23-5
78. ANS: C
Monocots have organs in threes. Dicots have organs in multiples of 4 or 5.
Feedback
A
B
C
D
This is not true of a dicot.
A eudicot is very similar to a dicot.
Exactly!
Check page 669 if you are a little confused.
PTS: 1
DIF: Bloom's Level C
REF: 669
TOP: 23-6
79. ANS: D
Lightweight pollen, as is found in a grass, is best transported by the wind. Heavier pollen must be carried by
other methods.
Feedback
A
B
C
D
No, this pollen is heavier.
Have a look on page 671.
This does not need lightweight pollen.
Yes!
PTS: 1
DIF: Bloom's Level D
REF: 671
TOP: 23-7
80. ANS: B
Tropical regions have about equal amounts of day light and night. They would be intermediate plants.
Feedback
A
B
C
D
Not quite. Try again.
Exactly!
Tropical regions don’t usually have these conditions.
If you are having trouble, look at pages 672–673.
PTS: 1
DIF: Bloom's Level E
REF: 672–673
TOP: 23-8
81. ANS: A
Plant that are not sensitive to photoperiod are called day-neutral.
Feedback
A
B
C
D
That is correct!
This has about equal number of hours of day or night.
Try again.
Have a look on pages 672–673.
PTS: 1
DIF: Bloom's Level C
REF: 672–673
TOP: 23-8
82. ANS: C
The response is to the number of hours of uninterrupted dark, therefore this is a better way to express it.
Feedback
A
B
C
D
What is the actual cue the plant responds to?
This is the opposite of a short-day plant.
Right on!
Have a look on pages 672–673.
PTS: 1
DIF: Bloom's Level E
TOP: 23-8
83. ANS: C
Pollen is a male gametophyte.
REF: 672–673
Feedback
A
B
C
D
Have a look at page 674.
Try again.
Great! You got it.
Not this one, but you are getting close.
PTS: 1
DIF: Bloom's Level C
TOP: 23-9
84. ANS: A
Double fertilization is one option.
REF: 674
Feedback
A
B
C
D
Way to go!
This is not a factor in plant fertilization.
Be careful. This seems like it could be right, but it is not.
Close, but not quite. Try again.
PTS: 1
DIF: Bloom's Level C
REF: 676
NAT: LS_2b
TOP: 23-10
85. ANS: A
Think of the structure of a strawberry. It is an aggregate, not a single fruit (as an apple).
Feedback
A
B
C
D
Great job!
A strawberry isn’t “dry” like a walnut, is it?
Not this one. A pineapple is an example of a multiple fruit.
Check page 677 if you need additional help.
PTS: 1
DIF: Bloom's Level B
REF: 677
TOP: 23-10
86. ANS: C
The beginning of growth into a mature plant is called seed germination.
Feedback
A
B
C
D
Allelopathy is not the right answer.
This is the spreading of the seeds.
Yes! You’ve got it.
Check page 678 if you need more help.
PTS: 1
DIF: Bloom's Level D
REF: 278
TOP: 23-11
87. ANS: B
Seeds may last from season to season if they enter a state of dormancy.
Feedback
A
B
C
D
Remember that dispersal is the spreading of the seeds.
Excellent!
If you are having trouble, check page 679.
Not this one. Try again.
PTS: 1
DIF: Bloom's Level D
REF: 679
TOP: 23-11
88. ANS: C
Photosynthesis depends on chlorophyll. So it cannot begin until the chloroplasts develop.
Feedback
A
B
C
D
Try again.
Check page 679 if you are having trouble.
Very good!
You are close.
PTS: 1
DIF: Bloom's Level D
REF: 675
TOP: 23-11
89. ANS: B
The pollen tube must be the length of the pistil to reach the ovule.
Feedback
A
B
C
D
Check page 676 again.
Great! You got it.
Not this one.
No, this is the male reproductive part.
PTS: 1
DIF: Bloom's Level C
TOP: 23-10
90. ANS: C
A plant embryo receives nourishment from the endosperm.
Feedback
A
B
C
D
No, this protects the seed.
The egg is the female gamete in a plant.
Exactly! Good job.
This is the male gamete.
REF: 676
PTS: 1
TOP: 23-9
DIF: Bloom's Level C
REF: 676
PROBLEM
91. ANS:
Diagrams should show water entering the cells of the root by osmosis and traveling to the xylem tissue.
Capillary action and transpiration pull water up through the stem of the plant into the leaves.
PTS: 1
DIF: Bloom's Level E
REF: 637–642
TOP: 22-2 | 22-4
92. ANS:
The plant has flowered when the day is short, or more properly when the length of darkness is relatively long.
This is a short-day plant. Its critical period is about 13 hours of dark.
PTS: 1
TOP: 23-8
DIF: Bloom's Level E
REF: 672–673
ESSAY
93. ANS:
Possible answer: Almost all plant cells have mitochondria. Mitochondria are organelles that use oxygen
molecules in a reaction to break down glucose or other simple carbohydrates to release energy. This energy
powers cellular functions. So, while plants produce oxygen during the process of photosynthesis, they also
use oxygen during the process of cellular respiration. Therefore, plants need both carbon dioxide and oxygen
to survive. Because of this, plants could not have lived on early Earth when there was little or no free oxygen
in the atmosphere. Therefore, plants must have evolved after free oxygen was present in the atmosphere. This
means that plants could not have been responsible for the introduction of free oxygen into Earth’s atmosphere
and the information presented in the television special is false.
PTS: 1
DIF: Bloom's Level F
REF: 632
NAT: LS_1e
TOP: 22-1
94. ANS:
In the mosses the gametophyte is the independently growing plant body. The gametophyte produces eggs and
sperm from an archegonium and antheridium respectively. The sperm need a thin film of water to swim to the
egg in the archegonium. The fertilized egg develops into the sporophyte plant, which grows on and is
dependent for nutrition on the gametophyte. The sporophyte produces haploid spores that develop into the
gametophytes. In the ferns, the sporophyte is the dominant (largest) plant body, the gametophyte is a tiny
plant, but one that grows independently of the sporophyte. The tiny gametophyte produces sperm and eggs in
antheridia and archegonia respectively and the sperm swim through a thin film of water to fertilize the egg.
The egg then develops into the fern plant, which produces spores on the underside of its frond. In conifers the
sporophyte is the dominant plant body. It produces megaspores and microspores that grow into the female and
male gametophytes that are dependent on the sporophyte plant. The female gametophyte produces eggs within
archegonia. The male gametophyte, or pollen grain, is a tiny structure that produces nonflagellated sperm
cells. The pollen grain is transferred on the wind to the female gametophyte where fertilization takes place.
The zygote develops into a sporophyte embryo, the seed, which subsequently develops into the mature plant.
PTS: 1
TOP: 23-3
DIF: Bloom's Level F
REF: 664–667