Chapter 30

¡Supera tus tareas y exámenes ahora con Quizwiz!

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. How many chromosomes should be in a megasporangium nucleus?

16

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. How many chromosomes should be in an embryo nucleus after fertilization?

16

Human survival 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

Which arranges the structures from largest to smallest, assuming that they belong to two generations of the same angiosperm?

carpel, ovary, ovule, embryo sac, egg

What statement about the pine life cycle is correct?

conifer pollen grains contain male gametophytes

What function is an advantage of seeds compared to spores?

containing a nutrient store for a developing sporophyte

In spruces and pines, what is an advantage of having needlelike leaves?

decreased surface area, reducing water loss

Which adaptations of land plants are likely to cause human health problems?

defenses against being eaten & adaptations related to wind dispersal of pollen

What is the process by which a trait present in an ancestral organism is modified by natural selection over time in descendants of that ancestor?

descent with modification

The embryo is...

diploid

The sporophyte generation is...

diploid

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

diploid sporophyte

What is unique to flowering plants?

double fertilization

What is a correct statement describing the life cycle of angiosperms?

double fertilization in the life cycle of seed plants results in the production of a diploid zygote and a triploid endosperm nucleus

What is a characteristic of all angiosperms?

double internal fertilization

After fertilization of the ovule, the _____ develops into the embryo of the mature seed

embryo

Oviparous (egg-laying) animals have internal fertilization (sperm cells encounter eggs within the female's body). Yolk and/or albumen is (are) provided to the embryo, and a shell is then deposited around the embryo and its food source. Eggs are subsequently deposited in an environment that promotes their further development, or are incubated by one or both parents. The yolk of an animal egg is similar to which structures in angiosperms?

endosperm

Suppose that the cells of seed plants, like the cells of human skin, produce a pigment upon increased exposure to ultraviolet radiation. What types of plant cells is most likely to produce this pigment?

epidermal cells of sporophyte megaphylls

In pine, the embryo develops within the __________.

female gametophyte

In gymnosperms, megaspores develop into __________.

female gametophytes

What statement correctly describes a portion of the pine life cycle?

female gametophytes use mitosis to produce eggs

What generation in the conifer cycle directly produces the megasporangium of pine ovules?

female sporophyte

What generation in the conifer life cycle most directly produces the integument of a pine seed?

female sporophyte

What structures directly produces the fruit of angiosperms?

female sporophyte

Which answer arranges the characteristics of plants in the order in which they evolved, from most ancient to most recent?

gametophyte dominance, sporophyte dependence; -> sporophyte dominance, gametophyte independence; -> sporophyte dominance, gametophyte dependence

In plants, the ________ produces haploid gametes (eggs and sperm) by mitosis, whereas the ________ produces haploid spores by meiosis.

gametophyte; sporophyte

Which organisms are the closest relatives of pine and spruce trees?

gnetophytes, cycads, and ginkgos

The gametophyte generation is...

haploid

The megaspore is...

haploid

In the pine, microsporangia form _____ microspores by _____.

haploid ... meiosis

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 are most consistent with your data?

hummingbirds promoted speciation less than did bees

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

immature sporophyte

Within a gymnosperm megasporangium, what develops before the others after fertilization occurs?

megaspore

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

micropyle

In angiosperms, what is correctly paired with its chromosome count?

microspore - n

What characteristic is functionally important in gametophyte cells of both angiosperms and gymnosperms?

mitochondria

What type of cell division does the generative of a male angiosperm gametophyte cell undergo to produce sperm cells?

mitosis

Stamens, sepals, petals, carpels, and pinecone scales are types of what structures?

modified leaves

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

one

What is present in angiosperms but not in gymnosperms?

ovaries

What contains multiple gymnosperm ovules?

ovulate cone

What is a characteristic that distinguishes gymnosperms and angiosperms from other plants?

ovules

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

petals

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

pollen

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

pollen

What is a key feature of seed plants facilitating life on land?

pollen

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

pollen grains

What problems will likely increase if the human population continues to increase?

reduction in plant & animal diversity

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

seed coat

Gymnosperms were most abundant during the _____.

Mesozoic

What is a structure that is a separate generation from the plant sporophyte?

a male gametophyte within a pollen grain

What pair do the structures play comparable roles in the plant & animal life cycles?

a plant sporophyte & an adult animal

Which of the following arranges the structures found on male pine trees from the largest structure to the smallest?

sporophyte, pollen cone, microsporangia, microspores, pollen nuclei

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

sporopollenin

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

A carpel is composed of _____.

stigma, style, ovary

One day, you go outside and see that the cars on the street are covered in a yellow "dust." What statement can be correctly applied to this "dust"?

the dust is pine pollen and is so abundant because the pines are wind-pollinated

Which feature of cycads makes them similar to many angiosperms?

they are pollinated by animals

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

they are probably wind pollinated

Which feature of cycads distinguishes them from most other gymnosperms?

they are wind pollinated

Many mammals have skins and mucous membranes that are sensitive to secretions of plants like poison oak. These secondary compounds are primarily adaptations that function in which way?

to inhibit herbivory

Where in an angiosperm would you find a megasporangium?

within an ovule contained within an ovary of a flower

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. How many chromosomes should be in a generative cell nucleus?

8

What is found inside a pollen grain?

the male gametophyte

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. How many chromosomes should be in an endosperm nucleus?

24

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. How many chromosomes should be in a tube cell nucleus?

8

All seed plants _____.

are heterosporous

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. What strategy would be most useful in the long term in reducing pressures faced by cacao farmers?

crossbreed cacao strains that produce high-quality cacao beans and ones resistant to a disease

The internal parts of the pollen grains of seed-producing plants are most similar to what structures in seedless plants?

fern gametophyte bearing only antheridia

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

flowers

Oviparous (egg-laying) animals have internal fertilization (sperm cells encounter eggs within the female's body). Yolk and/or albumen is (are) provided to the embryo, and a shell is then deposited around the embryo and its food source. Eggs are subsequently deposited in an environment that promotes their further development, or are incubated by one or both parents. The internal fertilization that occurs in egg-laying animals prior to shell deposition is similar to what process in angiosperms?

growth of pollen tube & delivery of sperm nuclei

After fertilization of the ovule, the _______ develops into the seed coat

integument

What statement is true about the gametophyte tissue that surrounds the pine embryo?

it functions as a haploid food reserve

What is a characteristic that would best support your assertion that a particular plant is an angiosperm?

it lacks gametangia

The Brazil nut tree, Bertholletia excels, is native to tropical rain forests of South America and produces large nuts. The large white part of a Brazil nut that people eat serves what function in nature?

it provides energy & nutrition to a germinating seeding

What statement are correct with regard to what physicians and pharmacists need to know about plants?

land plants produce poisons & medicines

What structure most directly produces the pollen tube of angiosperms?

male gametophyte

After fertilization of the ovule, the _____ develops into the food supply of the mature seed

megaspore

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

megaspores or microspores

The Brazil nut tree, Bertholletia excels, is native to tropical rain forests of South America. Scientists have discovered that the pale yellow flowers of Brazil nut trees cannot fertilize themselves and admit only female orchid bees as pollinators. 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 events should occur?

pollen transfer, pollen tube emerges from pollen grain, pollen tube enters micropyle, double fertilization

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. What statement best explains this observation?

pollen tubes did not enter all of the ovules in such pods, and fruit can develop even if all ovules within have not been fertilized.

What could best be investigated by measuring fruit production in plants?

pollination success

The major difference between angiosperms and gymnosperms comes from the __________.

presence or absence of a protective covering over the ovule

What describes a difference between wind-pollinated angiosperms compared with animal pollinated plants? Wind pollenated plants ________.

produce much more pollen because winds disperse pollen randomly

What is a statement that best describes an advantage of the reduced gametophytes in seed plants?

protection from drying out

What are the main components of a mature gymnosperm seed?

seed coat, embryo, & food supply

Why is seed dormancy adaptive for many plant species?

seed dormancy allows seeds to germinate when conditions are favorable for seedling growth

What statement describes a difference between seed plants and ferns?

seed plants produce two kinds of spores

The Brazil nut tree, Bertholletia excels, is native to tropical rain forests of South America. 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 into which moisture can then enter and allow the remaining seeds to germinate. The agouti is most directly involved in dispersal in which structure?

sporophyte embryos

The Brazil nut tree, Bertholletia excels, is native to tropical rain forests of South America. Scientists have discovered that the pale yellow flowers of Brazil nut trees cannot fertilize themselves and admit only female orchid bees as pollinators. 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. What statement best explains the failure to cultivate Brazil nut trees in these other locations?

the flowers were not pollinated due to the absence of female orchid bees

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 mistletoe genus Viscum, the outside of the seed is 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 stickiness of Viscum seeds is primarily an adaptation for dispersal rather than an adaptation for infecting host plant tissues?

the fruit is nutritious to the dispersing organisms

A researcher has developed two stains to use for visualizing different tissues of 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 will he/she/they most likely observe?

the pollen grains will have red interiors and blue exteriors

What is the most beneficial adaptation of the seed coats in angiosperm species whose seeds are dispersed by fruit-eating animals, as opposed to angiosperm species whose seeds are dispersed by other means?

the seed coat should be resistant to the animal's digestive enzymes

What is a major trend in land plant evolution over the past 200 million years?

the trend toward a sporophyte-dominated life cycle


Conjuntos de estudio relacionados

Living Environment - Mitosis and Meiosis

View Set

Upper and Lower crossed syndrome

View Set

Chapter 18: The French Revolution and Napoleon (1789-1799)

View Set

Unit 4 - Lessons 14-15: Early Civilizations in the Americas

View Set

The Spirit of Independence - Chapter 5

View Set