Biology 1407 Chapter 30

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

triploid endosperm
haploid gametophyte
diploid gametophyte
diploid sporophyte
haploid sporophyte

diploid sporophyte The sporophyte generation is the dominant generation of vascular plants.

All seed plants _____.

-are heterosporous
-produce flowers
-are nonvascular
-exhibit a dominant gametophyte generation
-produce antheridia and archegonia on the same gametophyte

are heterosporous All seed plants produce separate male and female spores.

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

heterospory
cones
ovules
pollen
sporophylls

pollen In bryophytes and seedless vascular plants, flagellated sperm must swim through a film of water to reach the egg cells. In seed plants, the use of airborne pollen to bring gametes together is a terrestrial adaptation.

Which of these is a major trend in land plant evolution?

the trend toward a gametophyte-dominated life cycle
the trend toward larger gametophytes
the trend toward smaller size
the trend toward a sporophyte-dominated life cycle

the trend toward a sporophyte-dominated life cycle

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

It retains its fertilized egg within its archaegonium.
It undergoes alternation of generations.
It produces seeds.
It lacks gametangia.

It lacks gametangia

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

sporopollenin
lignin present in cell walls
pollen
megaphylls

pollen

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

1 →? 2 → 3
3 → 1 → 2
2 → 1 → 3
3 → 2 → 1

3 → 1 → 2

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

sporangium
sporopollenin
sporophyll
stigma

sporopollenin

In terms of alternation of generations, the internal parts of the pollen grains of seed-producing plants are most similar to a _____.

-moss gametophyte bearing both male and female gametangia
-moss sporophyte
-fern gametophyte bearing only antheridia
-fern sporophyte

fern gametophyte bearing only antheridia

Which of the following sex and generation combinations directly produces the pollen tube of angiosperms?

female sporophyte
male sporophyte
female gametophyte
male gametophyte

male gametophyte

Which of these is a male gametophyte?

E

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

microsporangia … egg cell
archegonia … egg
antheridia … egg
archegonia … sperm cell
antheridia … sperm cell

archegonia … egg In pines, a megaspore repeatedly grows and divides, giving rise to a female gametophyte. The female gametophyte is the site in which egg-bearing gametophytes develop.

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

seed
immature female gametophyte
immature male gametophyte
immature sporophyte
food reserve for the immature sporophyte

immature sporophyte The diploid embryo will develop into a seedling and then into a mature pine tree.

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

integument
megaspore
micropyle
pollen cone
eggs

micropyle Pollen grains gain entry into the ovule via the micropyle.

Which of these statements is true about the gametophyte tissue that surrounds the pine embryo?

-It functions as a haploid food reserve.
-It functions as a triploid food reserve.
-It develops from the fusion of a microspore and a megaspore.
-It functions as a diploid food reserve.
-It is the remnant of the pollen tube.

It functions as a haploid food reserve This gametophyte tissue is a source of nourishment for the embryo.

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

integuments
one
three
two
four

one

In the pine, microsporangia form _____ microspores by _____.

triploid … fertilization
diploid … mitosis
diploid … meiosis
haploid … meiosis
haploid … mitosis

haploid … meiosis Diploid microsporangia form haploid microspores by meiosis.

Gymnosperms were most abundant during the _____.

Carboniferous
Cenozoic
Precambrian
Paleozoic
Mesozoic

Mesozoic

In gymnosperms megaspores develop into _____ .

male gametophytes
ovulate cones
female gametophytes
pollen grains
female sporophytes

female gametophytes Even though the gametophyte stage of alternation of generations is minimized in gymnosperms and angiosperms, spores still give rise to gametophytes.

In pine, the embryo develops within the _____.

macrogametophyte
microsporophyll
male gametophyte
female gametophyte
staminate cone

female gametophyte Large ovulate cones make megaspores that develop into female gametophytes, where one fertilized egg will develop into an embryo

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

decreased surface area, reducing water loss
increased surface area, increasing gas exchange
decreased surface area, reducing gas exchange
increased surface area, increasing photosynthesis

decreased surface area, reducing water loss

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

-A pollen tube slowly digests its way through the triploid endosperm.
-Pollen grains contain female gametophytes.
-Female gametophytes use mitosis to produce eggs.
-Seeds are produced in pollen-producing cones.

Female gametophytes use mitosis to produce eggs

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

1, 2, 3, 5, 4
4, 1, 2, 3, 5
4, 3, 2, 5, 1
1, 4, 3, 2, 5

1, 4, 3, 2, 5

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

female gametophyte
male sporophyte
female sporophyte
male gametophyte

female sporophyte

Use the following description to answer the question(s) below.

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 only
3 only
2 and 3
1 only

2 and 3

Ovules are found within structure _____

B The ovaries

Which of these is unique to flowering plants?

an embryo surrounded by nutritive tissue
pollen production
double fertilization
haploid gametophytes
a dominant sporophyte generation

double fertilization In flowering plants one sperm nucleus fertilizes the egg and the other sperm nucleus fuses with two other nuclei found within the ovule, thus forming triploid endosperm.

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

embryo sacs
male sporophytes
pollen grains
megaspores
endosperm

pollen grains

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

cotyledon
fruit
endosperm
sporophyte
seed coat

seed coat

A carpel is composed of _____.

ovule, megasporocyte, and anther
ovary, ovule, and anther
stigma, style, and ovary
zygote, anther, and endosperm
petal, sepal, and stamen

stigma, style, and ovary

A stamen consists of _____.

anther and filament
stigma and filament
stigma and style
ovary and sepal
stigma and anther

anther and filament

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.

ovulate cone
style
stigma
ovary
anther

stigma

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

-production of microspores versus megaspores
-presence or absence of vascular structures
-dominance or lack of dominance of the sporophyte generation
-presence or absence of a protective covering over the ovule
-presence or absence of alternation of generations

presence or absence of a protective covering over the ovule Angiosperms have a protective covering over the ovule. Gymnosperms do not. All the other traits listed are shared by both groups.

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

a sporophyte phase
a life cycle that involves alternation of generations
a vascular system
seeds
flowers

flowers

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?

stamens
ovaries
anthers
petals
carpels

petals attract pollinators

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 _____.

foster seed dispersal
decrease competition
inhibit herbivory
favor pollination

inhibit herbivory

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?

meiosis without subsequent cytokinesis
mitosis
binary fission
meiosis

mitosis

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

modified leaves
capable of photosynthesis
found on flowers
female reproductive parts

modified leaves

Use the following information to answer the question(s) below.

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

I, II, and III
II and III
I and II
I and III

II and III

A fruit is most commonly

a thickened style.
a mature ovary.
an enlarged ovule.
a modified root.
a mature female gametophyte.

a mature ovary

Where in an angiosperm would you find a megasporangium?

-packed into pollen sacs within the anthers found on a stamen
-inside the tip of a pollen tube
-enclosed in the stigma of a flower
-in the style of a flower
-within an ovule contained within an ovary of a flower

within an ovule contained within an ovary of a flower

Which of the following is not a characteristic that distinguishes gymnosperms and angiosperms from other plants?

alternation of generations
pollen
ovules
integuments
dependent gametophytes

alternation of generations

Gymnosperms and angiosperms have the following in common except

ovaries.
pollen.
ovules.
seeds.
vascular tissue.

ovaries

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

Megaspores or microspores
Sperm or eggs
Male or female gametophytes

Megaspores or microspores Review the life cycles of a pine tree and an angiosperm, respectively. In both life cycles, meiosis produces microspores (which develop into male gametophytes within pollen grains) or a megaspore (which develops into a female gametophyte or embryo sac within an ovule).

Consider the seed shown in this figure. Select the correct description of this seed.

-The structures of a seed are all diploid (2n).
-The embryo within the seed is the offspring of the sporophyte plant.
-A seed includes contributions from three separate generations of plants.

A seed includes contributions from three separate generations of plants. In addition to a sporophyte embryo, a seed has a seed coat derived from the integuments of the "grandparent" sporophyte and a food supply derived from the tissues of the "parent" gametophyte.

Select the 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.
-In angiosperm life cycles, the female gametophyte is the ovule.
-The life cycle of seed plants does not include a gametophyte generation.

Double fertilization in the life cycle of seed plants results in the production of a diploid zygote and a triploid endosperm nucleus. Review the life cycle of an angiosperm, note the ploidy of the embryo and endosperm within the seed.