Exam 30: Plant Diversity Ii: the Evolution of Seed Plants

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 metres tall, a source of high-quality timber, and a favourite 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 fertilise 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 same bees that pollinate the flowers of the Brazil nut trees also pollinate orchids, which are epiphytes (in other words, plants that grow on other plants); however, orchids cannot grow on Brazil nut trees. These observations explain ________.

Which of the following is a characteristic of all angiosperms?

Within a gymnosperm megasporangium, which of the following developmental sequences is correct, assuming fertilisation occurs?

Which of the following is a major trend in land plant evolution?

Unlike almost all ferns, seed plants ________.

Gymnosperms and angiosperms have the following in common except

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?

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?

Arrange the following structures, which can be found on male pine trees, from the largest structure to the smallest structure (or from most inclusive to least inclusive).

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 ________.

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

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?

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 colour by scarlet gilia: A mechanism for pollinator tracking. Science 227:315-17). -Late in the season, when only hawk moths were present, researchers painted the red flowers white. What would you expect?

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

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

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 tube cell nucleus?

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 metres tall, a source of high-quality timber, and a favourite 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 fertilise 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 taller a Brazil nut tree is, ________.

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 metres tall, a source of high-quality timber, and a favourite 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 fertilise 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?

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 nucleus after fertilisation?

Which of the following lines of evidence would best support your assertion that a particular plant is an angiosperm?