biology ch. 30 homework

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, is a source of high-quality lumber, and is 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, _____. 1. the more valuable it is as a source of lumber 2. the less useful it is to harpy eagles 3. the greater its photosynthetic rate relative to neighboring plants

1 and 3.

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 (they eat 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? 1. They have exposed ovules. 2. They have flagellated sperm. 3. They are pollinated by animals.

2 and 3.

Among plants known as legumes (beans, peas, alfalfa, clover, for example) the seeds are contained in a fruit that is itself called a legume, better known as a pod. Upon opening such pods, it is commonly observed that some ovules have become mature seeds, whereas other ovules have not. Thus, which of the following statements is (are) true? 1. The flowers that gave rise to such pods were not pollinated. 2. Pollen tubes did not enter all of the ovules in such pods. 3. There was apparently not enough endosperm to distribute to all of the ovules in such pods. 4. The ovules that failed to develop into seeds were derived from sterile floral parts. 5. Fruit can develop, even if all ovules within have not been fertilized.

2 and 5.

What adaptations should one expect of the seed coats of angiosperm species whose seeds are dispersed by frugivorous (fruit-eating) animals, as opposed to angiosperm species whose seeds are dispersed by other means? 1. The exterior of the seed coat should have barbs or hooks. 2. The seed coat should contain secondary compounds that irritate the lining of the animal's mouth. 3. The seed coat should be able to withstand low pHs. 4. The seed coat, upon its complete digestion, should provide vitamins or nutrients to animals. 5. The seed coat should be resistant to the animals' digestive enzymes.

3 and 5.

Arrange the following structures from largest to smallest, assuming that they belong to two generations of the same angiosperm. 1. ovary 2. ovule 3. egg 4. carpel 5. embryo sac

4, 1, 2, 5, 3 carpel ovary ovule embryo sac egg

Which of the following is a characteristic of all angiosperms? A). double internal fertilization B). carpels that contain microsporangia C). ovules that are not contained within ovaries D). free-living gametophytes

A). double internal fertilization.

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, is a source of high-quality lumber, and is 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. People who attempted to plant Brazil nuts in hopes of establishing plantations of Brazil nut trees played roles most similar to those of _____.

Agoutis.

Human survival literally depends on the produce of _____.

Angiosperms.

A stamen consists of _____.

Anther and filament.

In pines, the female gametophyte contains _____, each of which contains a(n) _____.

Archegonia ... Egg.

All seed plants _____.

Are heterosporous.

Which of the following directly produces the fruit of angiosperms? A). pollen tube B). ovary C). female gametophyte D). male gametophyte

B). ovary

The fruit of the mistletoe, a parasitic angiosperm, is a one-seeded berry. 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? It should ______.

Be nutritious to the dispersing organisms.

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, is a source of high-quality lumber, and is 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. Orchid bees are to Brazil nut trees as ________ are to pine trees.

Breezes.

Gymnosperms and angiosperms have the following in common except: A). seeds. B). vascular tissue. C). ovaries. D). ovules. E). pollen.

C). ovaries.

Which of these is unique to flowering plants? A). an embryo surrounded by nutritive tissue B). pollen production C). a dominant sporophyte generation D). double fertilization E). haploid gametophytes

D). double fertilization.

Conifers and pines both have needlelike leaves, with the adaptive advantage of _____.

Decreased surface area, reducing water loss.

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, is a source of high-quality lumber, and is 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 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 _____.

Decreasing their habitat.

When you look at a pine or maple tree, the plant you see is a _____.

Diploid sporophyte.

Which of these statements is true about the gametophyte tissue that surrounds the pine embryo? A). It develops from the fusion of a microspore and a megaspore. B). It is the remnant of the pollen tube. C). It functions as a diploid food reserve. D). It functions as a triploid food reserve. E). It functions as a haploid food reserve.

E). It functions as a haploid food reserve.

In pine, the embryo develops within the _____.

Female gametophyte.

In gymnosperms megaspores develop into _____ .

Female gametophytes.

Angiosperms are different from all other plants because only they have _____.

Flowers.

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 (they eat 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, what should be true?

Flying foxes can be dispersal agents of cycad seeds if the seeds sometimes get swallowed whole (in other words, without getting chewed).

The closest relatives of the familiar pine and spruce trees are _____.

Gnetophytes, Cycads, and Ginkgos.

In the pine, microsporangia form _____ microspores by _____.

Haploid ... Meiosis.

Harold and Kumar are pre-med and pre-pharmacy students, respectively. They complain to their biology professor that they should not have to study about plants because plants have little relevance to their chosen professions. Which adaptations of land plants are likely to provide Harold with future patients? I) sporophyte dominance II) defenses against herbivory III) adaptations related to wind dispersal of pollen

II and III.

In pines, an embryo is a(n) _____.

Immature sporophyte.

Many mammals have skins and mucous membranes that are sensitive to phenolic secretions of plants like poison oak (Rhus). These secondary compounds are primarily adaptations that _____.

Inhibit herbivory.

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 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). Refer to the paragraph on scarlet gilia. What is the significance of measuring fruit production?

It is a measure of pollination success.

What are the products of meiosis in the life cycle of a seed plant?

Megaspores or microspores.

Gymnosperms were most abundant during the _____.

Mesozoic.

In pine trees, pollen grains get to the ovule via the _____.

Micropyle.

Stamens, sepals, petals, carpels, and pinecone scales are all _____.

Modified leaves.

Of the four haploid cells produced by a pine cone's megasporocyte (megaspore mother cell), _____ survive(s).

One.

Unlike most angiosperms, grasses are pollinated by wind. As a consequence, some unnecessary parts of grass flowers have almost disappeared. Which of the following parts would you expect to be most reduced in a grass flower?

Petals.

The male gametophytes of flowering plants are also referred to as _____.

Pollen grains.

The adaptation that made possible the colonization of dry land environments by seed plants is most likely the result of the evolution of _____.

Pollen.

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, is a source of high-quality lumber, and is 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. Entrepreneurs attempted, but failed, to harvest nuts from plantations grown in Southeast Asia. Attempts to grow Brazil nut trees in South American plantations also failed. In both cases, the trees grew vigorously, produced healthy flowers in profusion, but set no fruit. Consequently, what is the likely source of the problem?

Pollination failure.

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 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). Refer to the paragraph on scarlet gilia. Late in the season, when only hawk moths were present, researchers painted the red flowers white. What would you expect?

Red flowers painted white would produce more fruits than red flowers would.

In flowering plants the integuments of the ovule develop into a(n) _____.

Seed coat.

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, is a source of high-quality lumber, and is 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 agouti is most directly involved with the Brazil nut tree's dispersal of _____.

Sporophyte embryos.

A carpel is composed of _____.

Stigma, style, and ovary.

In angiosperms, pollination is the transfer of pollen grain to the _____ of a flower on the same plant or another plant of the same species.

Stigma.

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, is a source of high-quality lumber, and is 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. Native peoples traditionally use Brazil nuts to treat stomach ache, inflammation, hypersensitivity, and hepatitis. Consequently, a scientist should be interested in promoting _____.

The evaluation of Brazil nut chemicals for use as potential drugs.

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

They are wind pollinated.

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 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). Refer to the paragraph on scarlet gilia. Some plants changed their flowers to lighter colors, and some retained the same darker color all season. Which plants do you expect produced more fruit?

Those that changed their color to a lighter shade.

In addition to seeds, which of the following characteristics is unique to the seed-producing plants? A). lignin present in cell walls B). megaphylls C). pollen D). sporopollenin

pollen.