Lesson 3: Plant Diversity

Question 1

Among plants known as legumes (beans, peas, alfalfa, clover, etc.), the seeds are contained in a fruit that is itself called a legume, better known as a pod. Upon opening such pods, it is commonly observed that some ovules have become mature seeds, whereas other ovules have not. Thus, which of the following statements is (are) true?

1. The flowers that gave rise to such pods were not pollinated.
2. Pollen tubes did not enter all of the ovules in such pods.
3. There was apparently not enough endosperm to distribute to all of the ovules in such pods.
4. The ovules that failed to develop into seeds were derived from sterile floral parts.
5. Fruit can develop, even if all ovules within have not been fertilized.

A. 1 and 5
B. 1 only
C. 2 and 5
D. 3 and 5
E. 2 and 4

Answer 1

C. 2 and 5

Question 2

Assuming that they all belong to the same plant, arrange the following structures from largest to smallest (or from most inclusive to least inclusive).

1. spores
2. sporophylls
3. sporophytes
4. sporangia

A. 3, 2, 4, 1
B. 3, 1, 4, 2
C. 2, 4, 3, 1
D. 2, 3, 4, 1
E. 3, 4, 2, 1

Answer 2

A. 3, 2, 4, 1

Question 3

Use the information that follows to answer the questions below.

Big Bend National Park in Texas is mostly Chihuahuan desert, where rainfall averages about 10 inches per year. Yet, it is not uncommon when hiking in this bone-dry desert to encounter mosses and ferns. One such plant is called “flower of stone.” It is not a flowering plant, nor does it produce seeds. Under arid conditions, its leaflike structures curl up. However, when it rains, it unfurls its leaves, which form a bright green rosette on the desert floor. Consequently, it is sometimes called the “resurrection plant.” At first glance, it could be a fern, a true moss, or a spike moss.
Which of the following features is most important in order for true mosses and ferns to survive and reproduce in the desert?

A. either that their gametophytes grow close together,
or that they are hermaphroditic
B. that the sporophytes have highly lignified vascular
tissues
C. that the sporophytes hug the ground, growing no
taller than a couple of inches
D. that the sporophytes occupy only permanently
shady, north-facing habitats

Answer 3

A. either that their gametophytes grow close together, or that they be hermaphroditic

Question 4

The three key reproductive adaptations of seed plant evolution include

A. dominant sporophyte, cones, ovules.
B. homospory, spores, cones.
C. dominant gametophyte, spores, seeds.
D. sporophylls, strobili, cones.
E. dominant sporophyte, seeds, pollen.

Answer 4

E. dominant sporophyte, seeds, pollen.

Question 5

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, 2, and 3
B. 2, 4, and 5
C. 1 and 3
D. 1, 3, and 5
E. 1 only

Answer 5

A. 1, 2, and 3

Question 6

Use the following information to answer the questions below.

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. Match the number of chromosomes present in each of the following onion tissues.
How many chromosomes should be in an embryo sac nucleus?

A. 4
B. 8
C. 16
D. 24
E. 32

Answer 6

B. 8

Question 7

Which of the following statements correctly describes a portion of the pine life cycle?

A. Seeds are produced in pollen-producing cones.
B. A pollen tube slowly digests its way through the
triploid endosperm.
C. Female gametophytes use mitosis to produce eggs.
D. Pollen grains contain female gametophytes.

Answer 7

C. Female gametophytes use mitosis to produce eggs.

Question 8

If a fern gametophyte is a hermaphrodite (that is, has both male and female gametangia on the same plant), then it

A. has antheridia and archegonia combined into a
single sex organ.
B. is actually not a fern, because of fern gametophytes
are always either male or female.
C. belongs to a species that is homosporous.
D. has lost the need for a sporophyte generation.
E. must be diploid.

Answer 8

C. belongs to a species that is homosporous.

Question 9

Which structure(s) must pass through the micropyle for successful fertilization to occur in angiosperms?

A. only one sperm nucleus
B. the pollen tube
C. two sperm nuclei
D. two of the responses above are correct.

Answer 9

D. two of the responses above are correct.

Question 10

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

A. Gametangia protect gametes from excess water.
B. Both male and female bryophytes produce
gametangia.
C. Bryophytes are limited to asexual reproduction.
D. Eggs and sperm of bryophytes swim toward one
another.
E. Embryophytes are small because they are in an early
developmental stage.

Answer 10

B. Both male and female bryophytes produce gametangia.

Question 11

Which of the following sex and generation combinations most directly produces the pollen tube?

A. male gametophyte
B. male sporophyte
C. female gametophyte
D. female sporophyte

Answer 11

A. male gametophyte

Question 12

Which of the following is a true statement about angiosperm carpels?

A. Carpels surround and nourish the female
gametophyte.
B. Carpels consist of highly modified microsporangia.
C. Carpels consist of anther and stamen.
D. Carpels are features of the gametophyte generation.
E. Carpels are structures that directly produce male
gametes.

Answer 12

A. Carpels surround and nourish the female gametophyte.

Question 13

On a field trip, a student in a marine biology class collects an organism that has differentiated organs, cell walls of cellulose, and chloroplasts with chlorophyll a. Based on this description, the organism could be a brown alga, a red alga, a green alga, a charophyte recently washed into the ocean from the freshwater or brackish water source, or a land plant washed into the ocean. The presence of which of the following features would definitively identify this organism as a land plant?

A. rings of cellulose-synthesizing complexes
B. alternation of generations
C. flagellated sperm
D. embryos
E. sporopollenin

Answer 13

D. embryos

Question 14

Which group is noted for the independence of gametophyte and sporophyte generations from each other?

A. angiosperms
B. ferns
C. charophytes
D. mosses, hornworts, and liverworts
E. gymnosperms

Answer 14

B. ferns

Question 15

Arrange the following terms from most inclusive to least inclusive.

1. embryophytes
2. green plants
3. seedless vascular plants
4. ferns
5. tracheophytes

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

Answer 15

A. 2, 1, 5, 3, 4

Question 16

Which of the following sex and generation combinations most directly produces the megasporangium of pine ovules?

A. female sporophyte
B. male gametophyte
C. female gametophyte
D. male sporophyte

Answer 16

A. female sporophyte

Question 17

Which structure is common to both gymnosperms and angiosperms?

A. ovary
B. anthers
C. carpel
D. stigma
E. ovule

Answer 17

E. ovule

Question 18

A botanist discovers a new species of plant in a tropical rain forest. After observing its anatomy and life cycle, he notes the following characteristics: 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. charophytes.
B. flowering plants.
C. gymnosperms.
D. ferns.
E. mosses.

Answer 18

D. ferns.

Question 19

The functional role of sporopollenin is primarily to

A. comprise spore surface structures that catch the
wind and assist in spore dispersal.
B. reduce dehydration.
C. provide nutrients to spores.
D. make spores less dense and able to disperse more
readily.
E. repel toxic chemicals.

Answer 19

B. reduce dehydration.

Question 20

Which of the following flower parts develops into a seed?

A. fruit
B. ovary
C. stamen
D. ovule

Answer 20

D. ovule

Question 21

Use the information that follows to answer the questions below.

Big Bend National Park in Texas is mostly Chihuahuan desert, where rainfall averages about 10 inches per year. Yet, it is not uncommon when hiking in this bone-dry desert to encounter mosses and ferns. One such plant is called “flower of stone.” It is not a flowering plant, nor does it produce seeds. Under arid conditions, its leaflike structures curl up. However, when it rains, it unfurls its leaves, which form a bright green rosette on the desert floor. Consequently, it is sometimes called the “resurrection plant.” At first glance, it could be a fern, a true moss, or a spike moss.
Which of the following characteristics is (are) possessed in common by true mosses, ferns, and spike mosses, and therefore becomes useless at helping to determine to which of these groups flower of stone belongs?
1. a sporophyte generation that is dominant
2. true leaves and roots
3. flagellated sperm
4. strobili
5. alternation of generations

A. 1 and 5
B. 2 and 3
C. 2, 4, and 5
D. 3 and 5
E. 5 only

Answer 21

D. 3 and 5

Question 22

Which of the following were probably factors that permitted early plants to successfully colonize land?

1. the relative number of potential predators (herbivores)
2. the relative number of competitors
3. the relative availability of symbiotic partners
4. air’s relative lack of support, compared to water’s support

A. 1 and 2
B. 1, 2, and 4
C. 3 and 4
D. 1, 2, and 3
E. 2 and 3

Answer 22

D. 1, 2, and 3

Question 23

Considering that the mature sporophytes of true mosses get their nutrition from the gametophytes on which they grow, and considering these generations as individual plants, what is true of the relationship between true moss sporophytes and gametophytes?

A. Sporophytes are commensalists of gametophytes.
B. Sporophytes are mutualists of gametophytes.
C. Sporophytes are endosymbionts of gametophytes.
D. Sporophytes are parasites of gametophytes.

Answer 23

D. Sporophytes are parasites of gametophytes.

Question 24

Which of the following sex and generation combinations most directly produces the integument of a pine seed?

A. male sporophyte
B. male gametophyte
C. female sporophyte
D. female gametophyte

Answer 24

C. female sporophyte

Question 25

Which of the following statements correctly describes a portion of the pine life cycle?

A. Seeds are produced in pollen-producing cones.
B. A pollen tube slowly digests its way through the
triploid endosperm.
C. Female gametophytes use mitosis to produce eggs.
D. Pollen grains contain female gametophytes.

Answer 25

C. Female gametophytes use mitosis to produce eggs.

Question 26

The generative cell of male angiosperm gametophytes is haploid. This cell divides to produce two haploid sperm cells. What type of cell division does the generative cell undergo to produce these sperm cells?

A. mitosis
B. binary fission
C. meiosis without subsequent cytokinesis
D. mitosis without subsequent cytokinesis
E. meiosis

Answer 26

A. mitosis

Question 27

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

A. ability to be dispersed
B. an internal reservoir of liquid water
C. integument(s)
D. waxy cuticle
E. a different type of sporopollenin

Answer 27

C. integument(s)