Deck 33: Plant Diversity

Question 1

The increase in opportunities for epiphytes in tropical rainforests following the evolution of angiosperms can be directly traced to the evolution of:

A)a warmer and wetter understory climate once eudicots dominate the canopy.
B)trees with weak apical dominance and xylem composed of fibers and vessels.
C)an increased diversity of animal pollinators.
D)ferns tolerant of understory conditions.

Answer 1

B

Question 2

Approximately 40% of living ferns are tropical epiphytes, a fact that supports the hypothesis that:

A)the origin and eventual domination of angiosperms in tropical forests both displaced and created new opportunities for other plant lineages.
B)plant lineages are conservative in their basic ecology and tend to diversify in the same environments in which they originated.
C)most fern diversity is in temperate forests.
D)epiphytic ferns are all that remain of an ancient diversification of ferns that preceded the evolution of angiosperms.

Answer 2

A

Question 3

Which of the following is a feature of land plants that is also found among the group of green algae from which land plants arose, and, therefore, may represent a "pre-adaptation" to life on land?

A)cuticle
B)multicellular diploid generation
C)sporopollenin
D)chloroplasts

Answer 3

C

Question 4

The last common ancestor of gymnosperms and angiosperms possessed which of the following characteristics?

A)pollen
B)flowers
C)seeds
D)vascular tissues
E)double fertilization

Question 5

Recall that angiosperms are, by far, the most diverse group of plants. In which group(s) has the existing diversity (though much less than that of the angiosperms) mostly radiated in conjunction with the rise of the angiosperms?

A)mosses
B)polypod ferns
C)cycads
D)gnetophytes

Question 6

Which of the following statements (which are all true) could contribute to a plausible hypothesis for why the alternation of generations evolved in the earliest land plants?

A)There were fewer chances for successful fertilization events on land compared with the ancestral fully aquatic environment.
B)Gametophytes lack the ability to form rigid (lignified)vascular tissues.
C)The biopolymer sporopollenin first evolved to protect the diploid stage of green algae.
D)Many gametophytes tolerate dessication.

Question 7

Which of the following plants were present on Earth 100 million years ago?

A)cycads
B)ferns and horsetails
C)conifers
D)angiosperms
E)All of these choices are correct.

Question 8

If angiosperms never existed, how would the environmental conditions of today's rainforest regions probably be different? These regions would be:

A)wetter.
B)drier.
C)colder.
D)hotter.
E)unchanged.

Question 9

Which of the following characteristics do land plants share with their closest algal relatives?

A)cytoplasm that may be continuously connected between whole populations of cells
B)an external waxy skin separating the plant body from its environment
C)multicellular haploid and diploid generations
D)populations of apical cells that maintain their meristematic identity

Question 10

As discussed in the text, angiosperms are, by far, the most diverse group of plants. According to the phylogenetic tree in Figure 33.1, which group would be considered the LEAST diverse?

A)green algae
B)lycophytes
C)gymnosperms
D)ferns and horsetails
E)Coleochaete

Question 11

The fossil record indicates that angiosperms first appeared how long ago?

A)100 million years ago
B)140 million years ago
C)300 million years ago
D)465 million years ago

Question 12

Which of the following statements is TRUE for cycads and ferns, but not for conifers or ginkgo?

A)Their extant diversity consists of a reduced set of "relict species" that have survived the appearance of the angiosperms by growing in environments where angiosperms do not have a clear advantage.
B)Their extant diversity is confined to the same environments in which their peak historical diversity once existed.
C)Their diversity has increased due to recent radiations into new environments, such as modern tropical rain forests created by angiosperms.
D)Their total diversity has declined since its peak, even as the extant diversity consists of recent radiations coinciding with the diversification of angiosperms.

Question 13

Which of the following plants were present on Earth 350 million years ago?

A)lycophytes
B)ferns and horsetails
C)conifers
D)angiosperms
E)only lycophytes and ferns/horsetails

Question 14

Species from which of the following groups died off as angiosperms diversified and became more abundant?

A)ferns
B)cycads
C)lycophytes
D)ginkgos

Question 15

Which of the following did NOT represent a challenge that plants faced in colonizing land from the ocean?

A)mechanical support
B)hydration
C)avoidance of herbivores
D)dispersal of sperm and offspring
E)protection from ultraviolet radiation

Question 16

Based on a lack of _____ in their fossil record, the earliest land plants are thought to have only been able to maintain photosynthesis intermittently.

A)vascular tissues
B)cuticle
C)stomata
D)sporopollenin

Question 17

As a result of the diversification and rise to ecological dominance of angiosperms, tropical forests are thought to have become:

A)cooler, shadier, and more humid.
B)warmer, shadier, and drier.
C)more humid, with the temperature and light environment unchanged.
D)cooler and drier.

Question 18

For which of the following groups is diversity higher today than in the Cretaceous period (145 to 166 million years ago)?

A)angiosperms
B)conifers
C)ferns
D)gnetophytes

Question 19

Which of the following occurrences is thought to be directly associated with the establishment of modern rainforests?

A)the evolution of the ability of angiosperms to support high transpiration rates
B)the increase in water uptake by vascular plants
C)the increase in photosynthetic oxygen production by vascular plants
D)the formation in the forest understory of dense mats of mosses and extensive beds of ferns

Question 20

Which taxonomic group of land plants still in existence today was the dominant group of land plants when the angiosperms began their rapid increase in speciation and distribution?

A)bryophytes
B)ferns and horsetails
C)lycophytes
D)gymnosperms

Question 21

With the appearance of angiosperms on Earth, all other types of plants became extinct. The conifers, cycads, and ferns seen today are in no way related to plant species existing millions of years ago.

Question 22

Hornworts are the most widely distributed bryophytes and are the most diverse with the largest number of species.

Question 23

Which of the following characteristics of bryophytes likely contribute to their small size relative to vascular plants growing in the same environment?

A)The male gametes of these land plants disperse in environmental water.
B)The leaves of bryophytes are only a few cell layers thick.
C)The longer-lived, ecologically dominant generation is the gametophyte.
D)The ecologically dominant generation is haploid.

Question 24

Land plants (not necessarily angiosperms) appeared in the fossil record approximately 200 million years ago, only slightly before the appearance of complex animals on Earth.

Question 25

Which of the following probably did NOT contribute to the diversification or ecological dominance of angiosperms in the Cretaceous period?

A)animal pollination
B)double fertilization
C)xylem that consisted of vessels and fibers
D)more efficient forms of rubisco

Question 26

Recent climate simulations suggest that angiosperms may have been necessary for the formation of tropical rainforests as we know them today.

Question 27

Which of the following statements is TRUE regarding angiosperms?

A)They are some of the earliest known plants to have existed on Earth, and they appeared-alongside lycophytes-approximately 400 million years ago.
B)The appearance of angiosperms on Earth did not affect the atmosphere or landscape; Earth's landscape has changed very little over the last 400 million years.
C)Although the appearance of angiosperms coincided with a decrease in the overall diversity of other groups of plants, their appearance also influenced the evolution of new species of non-angiosperm plants.
D)Over 400 million years ago on Earth, the landscape was dominated by angiosperm trees and shrubs.
E)Angiosperms are the second most diverse group of plants (the first is gymnosperms).

Question 28

How do sphagnum mosses contribute to the carbon cycle?

A)As decomposers, they release large amounts of CO₂ into the atmosphere.
B)They produce phenols, which release the carbon stored in peat bogs.
C)As heterotrophs, they remove large amounts of CO₂ from the atmosphere.
D)They acidify their environment, which limits decomposition and CO₂ release from peat bogs.

Question 29

The multicellular gametophytes of bryophytes are haploid.

Question 30

Of the different types of bryophytes, which has the sporophyte generation that lives the LONGEST?

A)mosses
B)hornworts
C)quillworts
D)horsetails
E)liverworts

Question 31

The sperm cells of bryophytes are dispersed by the wind.

Question 32

Which of the following groups both have short-lived sporophytes?

A)mosses and liverworts
B)mosses and hornworts
C)hornworts and liverworts

Question 33

Which of the following traits would never be found in a bryophyte?

A)a free-living sporophyte
B)stomata
C)desiccation resistance
D)water-conducting cells

Question 34

Angiosperms possess many adaptations. Which of the following statements is NOT true of angiosperms relative to other groups of plants?

A)Angiosperms have xylem vessels.
B)Angiosperms rely entirely on tracheid xylem.
C)Angiosperms have much higher rates of CO₂ uptake than other groups of plants.
D)Angiosperms increased the total plant diversity supported by terrestrial ecosystems.
E)Angiosperms can support greater rates of photosynthesis and transpiration than other groups of plants.

Question 35

Angiosperm-dominated tropical rainforests were very similar to the gymnosperm-dominated forests that preceded them.

Question 36

Which of the following traits were likely present in the last common ancestor of bryophytes?

A)multicellular sporophytes
B)vascular tissues
C)stomata
D)photosynthetic sporophytes
E)roots

Question 37

Which of the following groups of land plants first appeared in the fossil record MOST recently?

A)horsetails
B)ferns
C)gymnosperms
D)angiosperms

Question 38

Which of the following are examples of convergent evolution?

A)the water-conducting tissues of some bryophytes and that of ferns
B)the vascular cambia of quillworts (Isoetes)and that of angiosperms
C)the stomata of bryophytes and those of lycophytes
D)the cuticle of bryophytes and that of gymnosperms

Question 39

As the number of angiosperm species rose, what happened to the number of species of most other groups of land plants?

A)They increased.
B)They decreased.
C)They stayed roughly the same.

Question 40

Without the higher rates of transpiration exhibited by angiosperms, many tropical regions would:

A)have higher temperatures and lower rainfall.
B)have lower temperatures and lower rainfall.
C)have higher temperatures and higher rainfall.
D)have lower temperatures and higher rainfall.
E)be deserts.

Question 41

Based on your knowledge of how different plant groups have evolved arborescent (treelike) forms, in which of the following pairs of plant groups have large, tree-sized plant forms evolved independently?

A)monocots and eudicots
B)gymnosperms and eudicots
C)lycophytes and ferns
D)ferns and seed plants

Question 42

Bryophytes possess lignin in their xylem.

Question 43

You are walking along and you see a plant that is small, green, and growing close to the ground. When you look more closely, you see it has a very flexible stem and leaflike structures that lack veins. You are MOST likely observing a(n):

A)angiosperm.
B)gymnosperm.
C)lycopodium.
D)moss.
E)fern.

Question 44

Which of the following are characteristics of all bryophytes?

A)a thallus, or flattened body
B)sporophyte and gametophyte generations
C)stomata
D)swimming sperm
E)desiccation tolerance

Question 45

In all bryophytes, the sporophyte remains embedded in the thallus.

Question 46

Bryophytes are a(n):

A)monophyletic group of land plants.
B)paraphyletic group of land plants.
C)polyphyletic group of land plants.
D)unrelated group of land plants.
E)group of photosynthetic algae that are the ancestors of land plants.

Question 47

Plants that grow on other plants for structural support, but do not consume nutrients or energy from them, are called:

A)parasites.
B)lycophytes.
C)epiphytes.
D)photophytes.
E)tracheophytes.

Question 48

Sphagnum moss plays an important role in the global carbon cycle because it stores large amounts of organic carbon.

Question 49

The persistent and photosynthetic generation of bryophytes is, in general, constrained to be close to the ground:

A)because bryophytes are unable to produce cells specialized for long-distance transport of sugar or water.
B)in order to successfully disperse gametes.
C)because only the sporophyte stage has the genetic potential to grow in height.
D)because their spores require environmental water to disperse.

Question 50

You are studying epiphytic ferns growing in a seasonal tropical forest in which daily light rains supply enough water to keep the soil wet and epiphytic mosses and other plants moist enough for photosynthesis all year, but rains heavy enough to result in surface flows of water on the trunks and branches of the canopy trees occur only in winter. One year, the winter rains fail: How do you expect that the recruitment of new individuals to the fern population will respond compared with normal years?

A)The number of new sporophytes will be about the same, but the number of new gametophytes established will be much lower.
B)Neither the number of gametophytes nor sporophytes becoming established will be affected as the soil remains wet.
C)The number of new sporophytes will be reduced, but the number of new gametophytes will be about the same.
D)Both the number of new gametophytes and new sporophytes becoming established will be greatly reduced.

Question 51

Which of the following statements is TRUE?

A)Thalloid and leafy species are found in all groups of bryophytes.
B)A thallus is a thin stem that supports the leaves of bryophytes.
C)Bryophytes have true leaves similar to those found in gymnosperms.
D)All hornworts have leaflike photosynthetic structures.
E)All mosses have leaflike photosynthetic structures.

Question 52

Which of the following plants are bryophytes?

A)ferns
B)horsetails
C)mosses
D)angiosperms
E)gymnosperms

Question 53

Which of the following are living representatives of the first plant groups to diverge after plants moved onto land?

A)angiosperms
B)gymnosperms
C)ferns
D)liverworts
E)lycophytes

Question 54

In mosses, the green, leafy portion represents which generation in the alternation of generations?

A)haploid gametophyte
B)diploid gametophyte
C)haploid sporophyte
D)diploid sporophyte
E)haploid spore

Question 55

Because mosses and hornworts evolved independently for millennia, they do not have any similar characteristics; instead, they are grouped together as bryophytes due to genetic sequence similarities.

Question 56

How do bryophytes obtain water and CO₂?

A)They obtain CO₂ only through stomata and water through their roots.
B)They obtain water through their stomata and CO₂ through roots.
C)They absorb both CO₂ and water directly from the environment, without passing through stomata or roots.
D)They have difficulty absorbing water and CO₂ due to their thick, waxy cuticle.
E)They live in moist environments, so they do not need to absorb water or CO₂.

Question 57

Which of the following statements is TRUE regarding the vascular cambia of ancient (extinct) lycophytes?

A)Ancient lycophytes did not possess vascular cambia.
B)Ancient lycophytes had vascular cambia that formed only secondary phloem.
C)Ancient lycophytes had vascular cambia that formed only secondary xylem.
D)Ancient lycophytes had vascular cambia that formed both secondary xylem and secondary phloem.

Question 58

Examples of convergent evolution of bryophytes and vascular plants include:

A)mosses that attract insects, which then transport their spores.
B)the sporophyte generation being dependent on the gametophyte generation.
C)bryophytes living in habitats where roots do not confer an advantage.
D)mosses that are able to dry out and rehydrate functional photosynthetic tissues.
E)the evolution of lignified vascular tissue in some bryophytes.

Question 59

The group including ferns, whisk ferns, and horsetails includes plants with which of the following characteristics?

A)plants with leaves arranged in whorls or spirals
B)plants lacking leaves but possessing photosynthetic stems
C)plants having "underground" stems
D)plants whose gametophytes develop within their spore walls

Question 60

Bryophytes are small and simple. Some produce a flattened photosynthetic structure called a:

A)phallus.
B)thallus.
C)prometheus.
D)sporangium.
E)primordia.

Question 61

Lycophytes, ferns, and horsetails disperse and establish new, independent individuals by means of:

A)sperm.
B)seeds.
C)fronds.
D)spores.
E)thalloids.

Question 62

Coal is what is left of ancient forests after millions of years of exposure to subterranean high temperatures and pressures. What group of land plants is thought to have contributed the MOST to this fossil energy source?

A)lycophytes
B)sphagnum mosses in peat bogs
C)ferns and horsetails
D)bryophytes
E)conifer and angiosperm trees

Question 63

Which of the following statements is TRUE of Azolla?

A)It is an aquatic angiosperm with a larger and more persistent sporophyte generation.
B)It can be a net source of nitrogen in rice paddies, thus increasing rice yields.
C)It has a symbiosis with cyanobacteria, producing toxins that may accumulate in rice.
D)It is an aquatic fern with a larger and more persistent gametophyte generation.

Question 64

Isoetes is the only genus of (living) lycophytes that forms:

A)vascular cambia.
B)cork cambia.
C)vessels.
D)associations with nitrogen-fixing bacteria.

Question 65

Which of the vascular plants have swimming sperm and rely on liquid water in the environment to achieve fertilization?

A)gymnosperms and lycophytes
B)lycophytes and gymnosperms
C)ferns, horsetails, and gymnosperms
D)ferns, horsetails, and lycophytes

Question 66

Vascular cambia are observed in all lycophytes currently existing on Earth.

Question 67

Which of the following was an evolutionary innovation that contributed to the successful colonization of land by the first terrestrial plants?

A)leaves
B)sporophyte generation
C)roots
D)gametophyte generation
E)cuticle

Question 68

In vascular plants the _____ is larger than the _____.

A)diploid sporophyte; haploid gametophyte
B)diploid gametophyte; haploid sporophyte
C)haploid sporophyte; diploid gametophyte
D)haploid gametophyte; diploid sporophyte

Question 69

Which of the following correctly describes the "fern" we see when walking in the woods?

A)the diploid sporophyte
B)the haploid sporophyte
C)the diploid gametophyte
D)the haploid gametophyte

Question 70

Which of the following statements is TRUE of horsetails?

A)They have photosynthetic stems without leaves.
B)They do not form roots.
C)They produce tiny leaves arranged in whorls.
D)Their stems are solid with densely packed photosynthetic cells.
E)The fossil record indicates that they were always very small.

Question 71

Which of the following groups of land plants have evolved large tree-like forms?

A)ferns and horsetails
B)hornworts
C)lycophytes
D)seed plants

Question 72

Fern leaves can be large, with their photosynthetic surfaces divided into smaller units called:

A)pinnae.
B)fronds.
C)stems.
D)leaflets.
E)thalli.

Question 73

The first vascular plants had leaves.

Question 74

Vascular cambium (wood) evolved independently in several different groups of vascular plants.

Question 75

Fossil evidence demonstrates that the earliest vascular plants had:

A)leaves.
B)phloem.
C)stomata.
D)deep root systems.
E)vascular cambium.

Question 76

Although many types of plants decreased in diversity as angiosperms gained dominance, polypod ferns radiated in conjunction with the evolution of angiosperms. Why?

A)Angiosperms created new environments that ferns could inhabit.
B)Angiosperms and ferns could interbreed, increasing fern diversity.
C)Herbivores that once preyed on ferns began to target angiosperms.
D)In response to angiosperms, ferns developed secondary growth.
E)All of these choices are correct.

Question 77

Fern leaves emerge as tightly coiled structures called:

A)microsporangia.
B)fiddleheads.
C)protonema.
D)horsetails.
E)prothallus.

Question 78

Based on the fossil record of the Rhynie cherts, what structures were present in the earliest vascular plants?

A)stomata
B)cuticles
C)extensive root systems
D)multi-veined leaves
E)sporangia

Question 79

You are studying the spore dispersal distance in perfectly still air of two fern species found in your area, and you find that one species has an average dispersal distance many times that of the other, which is much larger than would likely be explained by chance. A reasonable hypothesis would be that your two species consist of a:

A)whisk fern and polypod fern.
B)whisk fern and horsetails.
C)marattiod and leptosporangiate fern.
D)leptosporangiate and polypod fern.

Question 80

Vascular plants can be divided into _____ group(s) according to the unit of dispersal that results in the establishment of independent individuals.

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