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

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

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. Native peoples traditionally use Brazil nuts to treat stomachache, inflammation, hypersensitivity, and hepatitis. Consequently, a scientist should be interested in promoting ________.

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

In seed plants, which of the following is part of a pollen grain and has a function most like that of the seed coat?

A researcher has developed two stains for use with seed plants. One stains sporophyte tissue blue; the other stains gametophyte tissue red. If the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur?

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?

Gymnosperms and angiosperms have the following in common except

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 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?

Arrange the following structures from largest to smallest, assuming that they belong to two generations of the same angiosperm.

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 now enter. The uneaten seeds may subsequently germinate. The taller a Brazil nut tree is, ________.

Spruces and pines both have needlelike leaves, with the adaptive advantage of ________.

Mistletoe is a plant that lives on trees and gains nutrition from them (that is, it is a parasite). The fruit of the mistletoe is a one-seeded berry and is consumed by birds. In members of the genus Viscum, the outside of the seed is viscous (sticky), which permits the seed to adhere to surfaces such as the branches of host plants or the beaks of birds. What should be expected of the fruit if the viscosity of Viscum seeds is primarily an adaptation for dispersal rather than an adaptation for infecting host plant tissues? The fruit ________.

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?

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

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 harpy eagle, Harpia harpyja, is the largest, most powerful raptor in the Americas. It nests only in trees taller than 25 meters. It is a "sloth specialist," but will also take agouti. Thus, if these eagles capture too many agoutis from a particular locale, they might contribute to their own demise by ________.

In addition to seeds, which of the following characteristics is unique to the seed-producing plants?

Immature seed cones of conifers are usually green before pollination, and flowers of grasses are inconspicuously colored. What does this indicate about their pollination?

Use the information to answer the following question. Açai berries come from trees that are native to the Amazon River Basin and now are the basis of many popular fruit drinks. Farmers with small areas harvest the berries in their family farms. Sometimes, they plant additional açai trees, weed out underbrush, and remove other trees in an effort to increase açai production. A recent study compared the forest characteristics of unmanipulated plots versus those where the farmers modified the plants in the plots. This study produced the following results: Characteristics Onmanipulated Plots Manipulated Plots Aai density (mean \# clumps/plot) 625 1,000 Number of vines 800/ 4,100/ Stem density of all plants 4,680/ 77.35/ Density of non-palm stems 1,400/ 4,000/ Which of the following conclusions are most reasonable to draw from the data presented?

Unlike almost all ferns, seed plants ________.