Question 1

Use the information to answer the following question.
The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters tall, a source of high-quality lumber, and a favorite nesting site for harpy eagles. As the rainy season ends, tough-walled fruits, each containing 8-25 seeds (Brazil nuts), fall to the forest floor. Brazil nuts are composed primarily of endosperm. About $50 million worth of nuts are harvested each year. Scientists have discovered that the pale yellow flowers of Brazil nut trees cannot fertilize themselves and admit only female orchid bees as pollinators. The agouti (Dasyprocta spp.), a cat-sized rodent, is the only animal with teeth strong enough to crack the hard wall of Brazil nut fruits. It typically eats some of the seeds, buries others, and leaves still others inside the fruit, which moisture can then enter and allow the remaining seeds to germinate.
If a female orchid bee has just left a Brazil nut tree with nectar in her stomach, and if she visits another flower on a different Brazil nut tree, what is the sequence in which the following events should occur?

Accepted Answer

A)  pollination, pollen tube emerges from pollen grain, pollen tube enters micropyle, double fertilization 
B)  pollination, pollen tube enters micropyle, pollen tube emerges from pollen grain, double fertilization 
C)  pollen tube emerges from pollen grain, pollination, pollen tube enters micropyle, double fertilization 
D)  pollen tube enters micropyle, pollen tube emerges from pollen grain, pollination, double fertilization

Question 2

Use the information to answer the following question.
The cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were dominant forms during the age of the dinosaurs. Though their sperm are flagellated, their ovules are pollinated by beetles. These beetles get nutrition from the pollen and shelter from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Cycads synthesize neurotoxins, especially in the seeds, that are effective against most animals, including humans.
On the Pacific island of Guam, large herbivorous bats called "flying foxes" commonly feed on cycad seeds, a potent source of neurotoxins. The flying foxes do not visit male cones. Consequently, which of the following statements should be accurate?

Accepted Answer

A)  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 because the toxin attacks the action of the central nervous system. 
C)  Flying foxes assist the beetles as important pollinating agents of the cycads. 
D)  Flying foxes disperse cycad seeds if the seeds sometimes get swallowed whole (in other words, without getting chewed).

Question 3

Use the information to answer the following question.
Scarlet gilia (Ipomopsis aggregata) usually has red flowers in an inflorescence of up to 250 flowers. In certain populations in the Arizona mountains, however, the flowers range from red to pink to white. In early summer, most (but not all) of the flowers were red. Six to eight weeks later, the same individual plants were still present; the flowers ranged from pink to white, and few red flowers were present. The major pollinators early in the season were two species of hummingbirds active during the day; they emigrated to lower elevations, and the major pollinator later in the season was a hawk moth (a type of moth). The hawk moth was most active at sunset and later, and it preferred light pink to white flowers after dark. When hummingbirds were present, more red flowers than white flowers produced fruit. When only hawk moths were present, more white flowers produced fruit (K. N. Paige and T. G. Whitham. 1985. Individual and population shifts in flower color by scarlet gilia: A mechanism for pollinator tracking. Science 227:315-17).
Which of the following proposed controls would be most appropriate for the experiment when, late in the season, scientists painted some of the red flowers white?

Accepted Answer

A)  Some red flowers should be painted pink 
B)  Some red and light colored flowers should be covered to prevent pollinator access. 
C)  Plants with light and dark colored flowers should be fertilized. 
D)  A necessary control would be to put red paint on some of the red flowers in order to control for the effects of paint.

Question 4

Which of the following problems will likely increase if the human population continues to increase?

Accepted Answer

A)  reduction in available medicines 
B)  decrease in global temperature 
C)  increase in disease-causing organisms 
D)  reduction in plant and animal diversity

Question 5

Use the information to answer the following question.
The cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were dominant forms during the age of the dinosaurs. Though their sperm are flagellated, their ovules are pollinated by beetles. These beetles get nutrition from the pollen and shelter from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Cycads synthesize neurotoxins, especially in the seeds, that are effective against most animals, including humans.
Which feature of cycads distinguishes them from most other gymnosperms?

Accepted Answer

A)  They have exposed ovules. 
B)  They have flagellated sperm. 
C)  They are pollinated by animals. 
D)  They have flagellated sperm and they are pollinated by animals.

Question 6

Use the information to answer the following question.
The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters tall, a source of high-quality lumber, and a favorite nesting site for harpy eagles. As the rainy season ends, tough-walled fruits, each containing 8-25 seeds (Brazil nuts), fall to the forest floor. Brazil nuts are composed primarily of endosperm. About $50 million worth of nuts are harvested each year. Scientists have discovered that the pale yellow flowers of Brazil nut trees cannot fertilize themselves and admit only female orchid bees as pollinators. The agouti (Dasyprocta spp.), a cat-sized rodent, is the only animal with teeth strong enough to crack the hard wall of Brazil nut fruits. It typically eats some of the seeds, buries others, and leaves still others inside the fruit, which moisture can then enter and allow the remaining seeds to germinate.
People who attempted to plant Brazil nuts in hopes of establishing plantations of Brazil nut trees played roles most similar to those of ________.

Accepted Answer

A)  agoutis 
B)  orchid bees 
C)  pollen tubes 
D)  harpy eagles

Question 7

Robbie and Saurab are pre-med and pre-pharmacy students, respectively. They complain to their biology professor that they should not have to study plants because plants have little relevance to their chosen professions. Which adaptations of land plants are likely to cause human health problems and provide Robbie with future patients?

Accepted Answer

A)  sporophyte dominance and defenses against herbivory 
B)  defenses against herbivory and adaptations related to wind dispersal of pollen 
C)  sporophyte dominance and adaptations related to wind dispersal of pollen 
D)  sporophyte dominance, defenses against herbivory, and adaptations related to wind dispersal of pollen

Question 8

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 a generative cell nucleus?

Accepted Answer

A)  8 
B)  16 
C)  24 
D)  32

Question 9

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

Accepted Answer

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

Question 10

Use the information to answer the following question.
Scarlet gilia (Ipomopsis aggregata) usually has red flowers in an inflorescence of up to 250 flowers. In certain populations in the Arizona mountains, however, the flowers range from red to pink to white. In early summer, most (but not all) of the flowers were red. Six to eight weeks later, the same individual plants were still present; the flowers ranged from pink to white, and few red flowers were present. The major pollinators early in the season were two species of hummingbirds active during the day; they emigrated to lower elevations, and the major pollinator later in the season was a hawk moth (a type of moth). The hawk moth was most active at sunset and later, and it preferred light pink to white flowers after dark. When hummingbirds were present, more red flowers than white flowers produced fruit. When only hawk moths were present, more white flowers produced fruit (K. N. Paige and T. G. Whitham. 1985. Individual and population shifts in flower color by scarlet gilia: A mechanism for pollinator tracking. Science 227:315-17).
Some plants continued to produce only dark (red) flowers whereas others produced lighter colored flowers later in the season. Which plants do you expect produced more fruit over the entire season?

Accepted Answer

A)  those that changed their color to a lighter shade 
B)  those that stayed dark 
C)  the same numbers of fruit on both 
D)  the plants whose flowers were always light colored

Question 11

Imagine that you wanted to know if speciation is more rapid in plant groups pollinated by bees or hummingbirds. To do this, you identified 20 genera of angiosperms that contained species pollinated by both types of animals. There were substantially more species in the groups that were pollinated by bees. What conclusions can you draw from your data?

Accepted Answer

A)  Hummingbirds promoted speciation more than did bees. 
B)  Hummingbirds promoted speciation less than did bees. 
C)  Each genus should be split into two new genera. 
D)  The rates of speciation were similar in groups pollinated by hummingbirds and bees.

Question 12

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 a megasporangium nucleus?

Accepted Answer

A)  8 
B)  16 
C)  24 
D)  32

Question 13

Use the information to answer the following question.
Theobroma cacao (cacao) is the tree that produces seeds that are turned into chocolate. These trees provide many poor people in the tropics with some cash income. However, these farmers face many obstacles to production of their crop, including temperature and rainfall changes caused by atmospheric CO₂ increases, and many diseases and pests. Analysis of the cacao genome showed that there is some (but not a lot) of genetic variation in the 10 major varieties.
Currently, cacao is harvested by cutting the cacao pods off trees with machetes. Which of the following strategies would increase the ease of harvesting?

Accepted Answer

A)  Breed trees that are shorter. 
B)  Breed trees that produce fruits that attach more strongly to the tree. 
C)  Breed trees resistant to diseases and pests. 
D)  Provide fertilizer in small quantities.

Question 14

Use the information to answer the following question.
The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters tall, a source of high-quality lumber, and a favorite nesting site for harpy eagles. As the rainy season ends, tough-walled fruits, each containing 8-25 seeds (Brazil nuts), fall to the forest floor. Brazil nuts are composed primarily of endosperm. About $50 million worth of nuts are harvested each year. Scientists have discovered that the pale yellow flowers of Brazil nut trees cannot fertilize themselves and admit only female orchid bees as pollinators. The agouti (Dasyprocta spp.), a cat-sized rodent, is the only animal with teeth strong enough to crack the hard wall of Brazil nut fruits. It typically eats some of the seeds, buries others, and leaves still others inside the fruit, which moisture can then enter and allow the remaining seeds to germinate.
Predict the most likely outcome to the population of Brazil nut trees if a disease decimated the agouti population.

Accepted Answer

A)  The population of large Brazil nut trees would remain constant for a while, but the population of new seedlings would likely increase in the long run. 
B)  The population of large Brazil nut trees would decline immediately, and the population of new seedlings would likely decrease in the future. 
C)  The population of large Brazil nut trees would remain constant for a while, but the population of new seedlings would likely decrease in the long run. 
D)  Both the population of large Brazil nut trees and new seedlings would increase in the long run.

Question 15

If one were to propose a new taxon of plants that included all the plants that are pollinated by animals, but excluded all plants that are not pollinated by animals, then this new taxon would be ________.

Accepted Answer

A)  monophyletic 
B)  paraphyletic 
C)  polyphyletic 
D)  identical in composition to the phylum Anthophyta

Question 16

Use the information to answer the following question.
The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters tall, a source of high-quality lumber, and a favorite nesting site for harpy eagles. As the rainy season ends, tough-walled fruits, each containing 8-25 seeds (Brazil nuts), fall to the forest floor. Brazil nuts are composed primarily of endosperm. About $50 million worth of nuts are harvested each year. Scientists have discovered that the pale yellow flowers of Brazil nut trees cannot fertilize themselves and admit only female orchid bees as pollinators. The agouti (Dasyprocta spp.), a cat-sized rodent, is the only animal with teeth strong enough to crack the hard wall of Brazil nut fruits. It typically eats some of the seeds, buries others, and leaves still others inside the fruit, which moisture can then enter and allow the remaining seeds to germinate.
The agouti is most directly involved with the Brazil nut tree's dispersal of ________.

Accepted Answer

A)  female gametophytes 
B)  sporophyte embryos 
C)  sporophyte megaspores 
D)  female gametes

Question 17

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

Accepted Answer

A)  dependent gametophytes 
B)  ovules 
C)  pollen 
D)  alternation of generations

Question 18

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

Accepted Answer

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

Question 19

Gymnosperms and angiosperms have the following in common except

Accepted Answer

A)  seeds. 
B)  pollen. 
C)  ovaries. 
D)  ovules.

Question 20

The advantages of the reduced gametophytes in seed plants include ________.

Accepted Answer

A)  protection from ultraviolet radiation, gain of nutrients from its own photosynthesis, and protection from drying out 
B)  protection from ultraviolet radiation, gain of nutrients from the sporophyte, and protection from drying out 
C)  protection of the spores from ultraviolet radiation and drying out, and gain of nutrients from the sporophyte 
D)  development of the seed

Exam 30: Plant Diversity II: The Evolution of Seed Plants