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

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?

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?

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?

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

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?

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 ________.

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?

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?

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

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?

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?

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?

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?

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.

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 ________.

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 ________.

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

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

Gymnosperms and angiosperms have the following in common except

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