Chapter 30: Plants II: The Evolution of Seed Plants

The cutting and burning of tropical rain forests leads to which of the following? 1. addition of CO₂ to the atmosphere 2. decreased removal of CO₂ from the atmosphere 3. greenhouse effect 4. global warming 5. decreasing sea level A) 1 only B) 1 and 2 C) 1, 2, and 3 D) 1, 2, 3, and 4 E) 2, 3, 4, and 5

1, 2, 3, and 4

Which trait(s) is (are) shared by many modern gymnosperms and angiosperms? 1. pollen transported by wind 2. lignified xylem 3. microscopic gametophytes 4. sterile sporophylls, modified to attract pollinators 5. endosperm A) 1 only B) 1 and 3 C) 1, 2, and 3 D) 1, 3, and 5 E) 2, 4, and 5

1, 2, and 3

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). 1. sporophyte 2. microspores 3. microsporangia 4. pollen cone 5. pollen nuclei A) 1, 4, 3, 2, 5 B) 1, 4, 2, 3, 5 C) 1, 2, 3, 5, 4 D) 4, 1, 2, 3, 5 E) 4, 3, 2, 5, 1

1, 4, 3, 2, 5

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. 70) How many chromosomes should be in an embryo nucleus? A) 4 B) 8 C) 16 D) 24 E) 32

16

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. 71) How many chromosomes should be in a megasporangium nucleus? A) 4 B) 8 C) 16 D) 24 E) 32

16

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. 61) 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. A) 1 only B) 2 only C) 3 only D) 2 and 3 E) 1, 2, and 3

2 and 3

Among plants known as legumes (beans, peas, alfalfa, clover, etc.) 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. A) 1 only B) 1 and 5 C) 2 and 4 D) 2 and 5 E) 3 and 5

2 and 5

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. 67) How many chromosomes should be in an endosperm nucleus? A) 4 B) 8 C) 16 D) 24 E) 32

24

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 pH's. 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. A) 4 only B) 1 and 2 C) 2 and 3 D) 3 and 5 E) 3, 4, and 5

3 and 5

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. 62) Which feature of cycads makes them similar to many angiosperms? 1. They have exposed ovules. 2. They have flagellated sperm. 3. They are pollinated by animals. A) 1 only B) 2 only C) 3 only D) 2 and 3 E) 1, 2, and 3

3 only

Arrange the following in the correct sequence, from earliest to most recent, in which these plant traits originated. 1. sporophyte dominance, gametophyte independence 2. sporophyte dominance, gametophyte dependence 3. gametophyte dominance, sporophyte dependence A) 1 → 2 → 3 B) 2 → 3 → 1 C) 2 → 1 → 3 D) 3 → 2 → 1 E) 3 → 1 → 2

3 → 1 → 2

Suppose that the cells of seed plants, like the skin cells of humans, produce a pigment upon increased exposure to UV radiation. Rank the following cells, from greatest to least, in terms of the likelihood of producing this pigment. 1. cells of sporangium 2. cells in the interior of a subterranean root 3. epidermal cells of sporophyte megaphylls 4. cells of a gametophyte A) 3, 4, 1, 2 B) 3, 4, 2, 1 C) 3, 1, 4, 2 D) 3, 2, 1, 4 E) 3, 1, 2, 4

3, 1, 4, 2

In a typical angiosperm, what is the sequence of structures encountered by the tip of a growing pollen tube on its way to the egg? 1. micropyle 2. style 3. ovary 4. stigma A) 4 → 2 → 3 → 1 B) 4 → 3 → 2 → 1 C) 1 → 4 → 2 → 3 D) 1 → 3 → 4 → 2 E) 3 → 2 → 4 → 1

4 → 2 → 3 → 1

Within a gymnosperm megasporangium, what is the correct sequence in which the following should appear during development, assuming that fertilization occurs? 1. sporophyte embryo 2. female gametophyte 3. egg cell 4. megaspore A) 4 → 3 → 2 → 1 B) 4 → 2 → 3 → 1 C) 4 → 1 → 2 → 3 D) 1 → 4 → 3 → 2 E) 1 → 4 → 2 → 3

4 → 2 → 3 → 1

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 A) 4, 2, 1, 5, 3 B) 4, 5, 2, 1, 3 C) 5, 4, 3, 1, 2 D) 5, 1, 4, 2, 3 E) 4, 1, 2, 5, 3

4, 1, 2, 5, 3

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. 66) How many chromosomes should be in a tube cell nucleus? A) 4 B) 8 C) 16 D) 24 E) 32

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. 68) How many chromosomes should be in a generative cell nucleus? A) 4 B) 8 C) 16 D) 24 E) 32

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. 69) How many chromosomes should be in an embryo sac nucleus? A) 4 B) 8 C) 16 D) 24 E) 32

8

Which of the following is a true statement about angiosperm carpels? A) Carpels are features of the gametophyte generation. B) Carpels consist of anther and stamen. C) Carpels are structures that directly produce male gametes. D) Carpels surround and nourish the female gametophyte. E) Carpels consist of highly modified microsporangia.

Carpels surround and nourish the female gametophyte

Which of the following statements is true of the pine life cycle? A) Cones are homologous to the capsules of moss plants. B) The pine tree is a gametophyte. C) Male and female gametophytes are in close proximity during gamete synthesis. D) Conifer pollen grains contain male gametophytes. E) Double fertilization is a relatively common phenomenon.

Conifer pollen grains contain male gametophytes

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

Female gametophytes use mitosis to produce eggs

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. 64) 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? A) The 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. C) The flying foxes assist the beetles as important pollinating agents of the cycads. D) Flying foxes can be dispersal agents of cycad seeds if the seeds sometimes get swallowed whole (in other words, without getting chewed).

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

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? A) It should be drab in color. B) It should be colored so as to provide it with camouflage. C) It should be nutritious. D) It should secrete enzymes that can digest bark. E) It should contain chemicals that cause birds to fly to the ground and vomit.

It should be nutritious

Which of the following is true concerning flowering plants? A) The flower includes sporophyte tissue. B) The gametophyte generation is dominant. C) The gametophyte generation is what we see when looking at a large plant. D) The sporophyte generation is not photosynthetic. E) The sporophyte generation consists of relatively few cells within the flower.

The flower includes sporophyte tissue.

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? A) The pollen grains will be pure red. B) The pollen grains will be pure blue. C) The pollen grains will have red interiors and blue exteriors. D) The pollen grains will have blue interiors and red exteriors. E) Insofar as the pollen grains are independent of the plant that produced them, they will not absorb either stain.

The pollen grains will have red interiors and blue exteriors.

Given the differences between angiosperms and gymnosperms in the development of the integument(s), which of these statements is the most logical consequence? A) The seed coats of angiosperms should be relatively thicker than those of gymnosperms. B) It should be much more difficult for pollen tubes to enter angiosperm ovules than for them to enter gymnosperm ovules. C) The female gametophytes of angiosperms should not be as well protected from environmental stress as should those of gymnosperms. D) As a direct consequence of such differences, angiosperms should have fruit. E) Angiosperm seeds should be more susceptible to desiccation.

The seed coats of angiosperms should be relatively thicker than those of gymnosperms.

What is true of stamens, sepals, petals, carpels, and pinecone scales? A) They are female reproductive parts. B) None are capable of photosynthesis. C) They are modified leaves. D) They are found on flowers. E) They are found on angiosperms.

They are modified leaves

The seeds of orchids are among the smallest known, with virtually no endosperm and with miniscule seed leaves. Consequently, what should one expect to be true of such seeds? A) They require extensive periods of dormancy during which the embryo develops. B) They are surrounded by brightly colored, sweet fruit. C) They germinate very soon after being released from the ovary. D) The developing embryo within is dependent upon the gametophyte for nutrition. E) The sporophytes that produce such seeds are wind-pollinated.

They germinate very soon after being released from the ovary.

Which of the following statements is true of monocots? A) They are currently thought to be polyphyletic. B) The veins of their leaves form a netlike pattern. C) They, along with the eudicots, magnoliids, and basal angiosperms, are currently placed in the phylum Anthophyta. D) Each possesses multiple cotyledons. E) They are in the clade that includes most of our crops, except the cereal grains.

They, along with the eudicots, magnoliids, and basal angiosperms, are currently placed in the phylum Anthophyta.

Which structure(s) must pass through the micropyle for successful fertilization to occur in angiosperms? A) only one sperm nucleus B) two sperm nuclei C) the pollen tube D) Two of the responses above are correct

Two of the responses above are correct

A fruit is most commonly A) a mature ovary. B) a thickened style. C) an enlarged ovule. D) a modified root. E) a mature female gametophyte.

a mature ovary

Which of the following is not a characteristic that distinguishes gymnosperms and angiosperms from other plants? A) alternation of generations B) ovules C) integuments D) pollen E) dependent gametophytes

alternation of generations

Over human history, which process has been most important in improving the features of plants that have long been used by humans as staple foods? A) genetic engineering B) artificial selection C) natural selection D) sexual selection E) pesticide and herbicide application

artificial selection

How have fruits contributed to the success of angiosperms? A) by nourishing the plants that make them B) by facilitating dispersal of seeds C) by attracting insects to the pollen inside D) by producing sperm and eggs inside a protective coat E) by producing triploid cells via double fertilization

by facilitating dispersal of seeds

All of the following cellular structures are functionally important in cells of the gametophytes of both angiosperms and gymnosperms except A) haploid nuclei. B) mitochondria. C) cell walls. D) chloroplasts. E) peroxisomes.

chloroplasts

Hypothetically, one of the major benefits of double fertilization in angiosperms is to A) decrease the potential for mutation by insulating the embryo with other cells. B) increase the number of fertilization events and offspring produced. C) promote diversity in flower shape and color. D) coordinate developmental timing between the embryo and its food stores. E) emphasize embryonic survival by increasing embryo size.

coordinate developmental timing between the embryo and its food stores

Cutting down rain forests can lead to A) decreased temperatures. B) decreased rainfall. C) decreased atmospheric carbon dioxide. D) increased biodiversity. E) more than one of these.

decreased rainfall

The seed coat's most important function is to provide A) a nonstressful environment for the megasporangium. B) the means for dispersal. C) dormancy. D) a nutrient supply for the embryo. E) desiccation resistance.

desiccation resistance

Which of the following is a characteristic of all angiosperms? A) complete reliance on wind as the pollinating agent B) double internal fertilization C) free-living gametophytes D) carpels that contain microsporangia E) ovules that are not contained within ovaries

double internal fertilization

Which of the following sex and generation combinations most directly produces the fruit? A) male gametophyte B) female gametophyte C) male sporophyte D) female sporophyte

female sporophyte

Which of the following sex and generation combinations most directly produces the integument of a pine seed? A) male gametophyte B) female gametophyte C) male sporophyte D) female sporophyte

female sporophyte

Which of the following sex and generation combinations most directly produces the megasporangium of pine ovules? A) male gametophyte B) female gametophyte C) male sporophyte D) female sporophyte

female sporophyte

In terms of alternation of generations, the internal parts of the pollen grains of seed-producing plants are most similar to a A) moss sporophyte. B) moss gametophyte bearing both male and female gametangia. C) fern sporophyte. D) hermaphroditic fern gametophyte. E) fern gametophyte bearing only antheridia.

fern gametophyte bearing only antheridia

Which group is noted for the independence of gametophyte and sporophyte generations from each other? A) ferns B) mosses, hornworts, and liverworts C) charophytes D) angiosperms E) gymnosperms

ferns

Angiosperms are the most successful terrestrial plants. Which of the following features is unique to them and helps account for their success? A) wind pollination B) dominant gametophytes C) fruits enclosing seeds D) embryos enclosed within seed coats E) sperm cells without flagella

fruits enclosing seeds

Gymnosperms differ from both extinct and extant (living) ferns because they A) are woody. B) have macrophylls. C) have pollen. D) have sporophylls. E) have spores.

have pollen

What is the greatest threat to plant diversity? A) insects B) grazing and browsing by animals C) pathogenic fungi D) competition with other plants E) human population growth

human population growth

Generally, wind pollination is most likely to be found in seed plants that grow A) close to the ground. B) in dense, single-species stands. C) in relative isolation from other members of the same species. D) along coastlines where prevailing winds blow from the land out to sea. E) in well-drained soils.

in dense, single-species stands

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 A) prevent desiccation. B) favor pollination. C) foster seed dispersal. D) decrease competition. E) inhibit herbivory.

inhibit herbivory

Which of the following is most important in making the typical seed more resistant to adverse conditions than the typical spore? A) a different type of sporopollenin B) an internal reservoir of liquid water C) integument(s) D) ability to be dispersed E) waxy cuticle

integument(s)

Reptilian embryos are protected from desiccation by a leathery shell. Similarly, which pair of structures protects seed plants' embryos and male gametophytes, respectively, from desiccation? A) ovules-waxy cuticle B) ovaries-filaments C) fruits-stamens D) pollen grains-waxy cuticle E) integuments-sporopollenin

integuments-sporopollenin

Which of the following sex and generation combinations most directly produces the pollen tube? A) male gametophyte B) female gametophyte C) male sporophyte D) female sporophyte

male gametophyte

With respect to angiosperms, which of the following is incorrectly paired with its chromosome count? A) egg-n B) megaspore-2n C) microspore-n D) zygote-2n E) sperm-n

megaspore-2n

The generative cell of male angiosperm gametophytes is haploid. This cell divides to produce two haploid sperm cells. What type of cell division does the generative cell undergo to produce these sperm cells? A) binary fission B) mitosis C) meiosis D) mitosis without subsequent cytokinesis E) meiosis without subsequent cytokinesis

mitosis

Carpels and stamens are A) sporophyte plants in their own right. B) gametophyte plants in their own right. C) gametes. D) spores. E) modified sporophylls.

modified sporophylls

A botanist was visiting a tropical region for the purpose of discovering plants with medicinal properties. All of the following might be ways of identifying potentially useful plants except A) observing which plants sick animals seek out. B) observing which plants are the most used food plants. C) observing which plants animals do not eat. D) collecting plants and subjecting them to chemical analysis. E) asking local people which plants they use as medicine.

observing which plants are the most used food plants

Angiosperm double fertilization is so-called because it features the formation of A) two embryos from one egg and two sperm cells. B) one embryo from one egg fertilized by two sperm cells. C) two embryos from two sperm cells and two eggs. D) one embryo involving one sperm cell and an endosperm involving a second sperm cell. E) one embryo from two eggs fertilized by a single sperm cell.

one embryo involving one sperm cell and an endosperm involving a second sperm cell

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

ovaries

Which of the following flower parts develops into the pulp of a fleshy fruit? A) stigma B) style C) ovule D) ovary E) micropyle

ovary

Which of the following flower parts develops into a seed? A) ovule B) ovary C) fruit D) stamen

ovule

Which structure is common to both gymnosperms and angiosperms? A) stigma B) carpel C) ovule D) ovary E) anthers

ovule

In addition to seeds, which of the following characteristics are unique to the seed-producing plants? A) sporopollenin B) lignin present in cell walls C) pollen D) use of air currents as a dispersal agent E) megaphylls

pollen

Which of the following can be found in gymnosperms? A) nonfertile flower parts B) triploid endosperm C) fruits D) pollen E) carpels

pollen

Which of the following are structures of angiosperm gametophytes? A) immature ovules B) pollen tubes C) ovaries D) stamens E) sepals

pollen tubes

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. 65) If one were to erect a new taxon of plants that included all plants that are pollinated by animals, and only plants that are pollinated by animals, then this new taxon would be A) monophyletic. B) paraphyletic. C) polyphyletic. D) identical in composition to the phylum Anthophyta. E) identical in composition to the phylum Cycadophyta.

polyphyletic

A botanist discovers a new species of land plant with a dominant sporophyte, chlorophylls a and b, and cell walls made of cellulose. In assigning this plant to a phylum, which of the following, if present, would be least useful? A) endosperm B) seeds C) sperm that lack flagella D) flowers E) spores

spores

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) sporophyll B) male gametophyte C) sporopollenin D) stigma E) sporangium

sporopollenin

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. 63) If the beetles survive by consuming cycad pollen, then whether the beetles should be considered mutualists with, or parasites of, the cycads depends upon A) the extent to which their overall activities affect cycad reproduction. B) the extent to which the beetles are affected by the neurotoxins. C) the extent to which the beetles damage the cycad flowers. D) the distance the beetles must travel between cycad microsporophylls and cycad megasporophylls.

the extent to which their overall activities affect cycad reproduction

Where in an angiosperm would you find a megasporangium? A) in the style of a flower B) inside the tip of a pollen tube C) enclosed in the stigma of a flower D) within an ovule contained within an ovary of a flower E) packed into pollen sacs within the anthers found on a stamen

within an ovule contained within an ovary of a flower