Chapter 28

There are approximately _______ living species of horsetails (a monilophyte).

15

Approximately _______ species of moss (Bryophyta) have been described.

15,000

Earth is estimated to be 4.65 billion years old. Although life first appeared about 3.7 billion years ago, land plants did not appear until _______ years ago.

400-500 million

A club moss sporophyte with a single terminal strobilus produces 12,000 spores. How many spores would the sporophyte have produced if it had dichotomously branched twice before the strobili developed?

48,000

Which of the following is a universal feature of the life cycles of land plants?

Alteration of generations between haploid gametophytes and diploid sporophytes

Which of the following characteristics is a synapomorphy for green algae and land plants?

Chlorophyll b

An abundant type of coal is formed almost entirely from fossilized spores. Which of the following plant groups was most likely the source of those spores?

Club mosses

Which of the following land plant groups possesses a microphyll-type leaf?

Club mosses

Which group of seedless vascular plants from the list below matches the following description? The branching sporophyte bodies are large and nutritionally independent; they have true roots and tracheids containing lignin.

Club mosses Horsetails Ferns Both b and c All of the above

The first ferns appeared during the _______ period.

Devonian

Several important adaptations evolved in the common ancestor of land plants that allowed the successful colonization of land. Which of the following is one of those changes?

Evolution of a waxy cuticle

What group on the list below matches the following description? The gametophytes are nutritionally independent, they have chloroplasts and stomata, and they lack true leaves, stems, and roots.

Hornworts Mosses

Hornwort sporophytes have a basal region of cell division rather than an apical region. What effect does this have on sporophyte function in hornworts, as compared with mosses?

It allows spores to be continually made and released as long as the sporophyte lives, while in moss only one set of spores is made per sporophyte.

The plants classified as embryophytes include which of the following groups?

Land plants

What group on the list below matches the following description? The gametophytes are green leaflike layers that lie flat on the ground.

Liverworts

Which of the following represents the most ancient surviving land plant lineage?

Liverworts

What group on the list below matches the following description? The gametophytes are the conspicuous visible green structure, they live mostly in moist terrestrial habitats, and they lack true leaves, stems, and roots

Liverworts Hornworts Mosses

Which of the following regarding the two leaf types (microphylls and megaphylls) is false?

Megaphylls arose from the flattening of a dichotomous branching system.

_______ has been used as evidence to support the idea that land plants arose from a green algal clade.

Microscopic structures DNA sequences Biochemistry Morphological structures

Which of the following regarding vascular plant evolution is false?

The fossil record shows that vascular plants appeared on land after the first land animals.

How can nonvascular plants survive on land without true leaves, stems, and roots?

They have a thick cuticle to prevent water loss. They live in moist habitats.

Which of the following statements about the hornworts is true?

They possess stomata.

Land plants likely arose from a green alga, such as an ancient stonewort species. If you could go back in time and examine them, what feature would you look for to distinguish an early land plant from a stonewort?

a cuticle

The nonvascular plants have a number of structures or characteristics that allow them to obtain water and minerals in the absence of a vascular system. These include all of the following except

an extensive root system to take up water from soil

A property shared by the sporophyte of mosses and ferns is

apical cell division.

Selaginella is a heterosporous lycophyte. If you wanted to study Selaginella gametophyte structure, the most important reason why you must collect more than one sample is

because microgametophytes will have a different structure than the megagametophytes.

Primary endosymbiosis gave rise to ________ in the clade of photosynthetic eukaryotes.

chloroplasts

During the Carboniferous period, forests of large trees, including _______, dominated the landscape.

club mosses horsetails tree ferns Both b and c All of the above

The cyanobacteria found in the internal mucilage-filled cavities of hornworts serve to

convert atmospheric nitrogen gas into a form usable by the plant.

The sporophyte of the moss Sphagnum

depends on the gametophyte for nutrients

The nonvascular plant clades (including moss) require liquid water for fertilization during sexual reproduction because

eggs are fertilized by a flagellated sperm that swims to the egg.

Protection of the embryo by parental tissue was a defining step in the evolution of

embryophytes.

The sporophyte generation

extends from the zygote through the adult diploid plant

Ferns are vascular plants, but tend to prosper in wet areas because

ferns have swimming sperm

All land plants produce _______ by mitosis and _______ by meiosis.

gametes; spores

When observing a liverwort in nature, the larger, more visible plant is the _______, whereas in horsetails, the larger, more visible plant is the _______.

gametophyte; sporophyte

In a eukaryotic species that has "alternation of generations

haploid and diploid stages of the life cycle alternate and both have a multicellular stage.

The nutritionally independent stage of the life cycle of a liverwort is the

haploid gametophyte.

The sporophyte of a vascular plant is nutritionally _______; the sporophyte of a nonvascular plant is nutritionally _______.

independent; dependent

Vascular plants are thought to be the result of a single evolutionary event: the evolution of a wholly new cell type, the tracheid. This cell type

is the principal water-conducting element of the xylem in all early vascular plants.

As land plants evolved, the sporophyte generation became _______ and _______ dependent on the gametophyte generation.

larger; less

Nonvascular plants

may be in a mutualistic association with a fungus and/or a cyanobacterium

Club mosses and the horsetails share all of the following characteristics except

microphyll-type leaves

An important synapomorphy of the euphyllophytes is overtopping, a growth pattern in which one branch differentiates from and grows beyond the others. Overtopping growth allowed for

more access to sunlight for photosynthesis. more access to wind for CO2 uptake.

You find a mat of short green "leafy" plants growing on your neighbor's front lawn. They lack vascular tissue and are dispersing lots of spores from small brown stalks. The plants are most likely a colony of

moss

What group on the list below matches the following description? The gametophyte starts as a branched filamentous structure called a protonema, and many types contain hydroid cells.

mosses.

Plants moved from an aqueous environment and colonized the land sometime during the Paleozoic era. In order to thrive on land, plants had to develop

physical support structures and mechanisms for gamete dispersal.

The first vascular plants were probably

rhyniophytes.

One important benefit of the evolution of xylem was the development of a mechanism for

rigid structural support.

Fossilized remains of a rhyniophyte show that these extinct plants lacked

roots leaves. Both a and c

Mosses are dependent on external water for sexual reproduction because

sperm must swim through water to reach and fertilize eggs

The most stable resting stage in the life cycle of the seedless vascular plants is the

spore.

In some liverworts, _______ are "thrown" from the capsule by structures that shorten and compress as they dry out.

spores

Within vascular plants, the large prominent plant is the _______; in nonvascular plants it is the _______.

sporophyte; gametophyte

Hornworts (Anthocerophyta) may be distinguished from liverworts (Hepatophyta) and mosses (Bryophyta) by the fact that

their cells contain a single chloroplast.

A field biologist has brought you a plant fossil to analyze. To determine if it is a vascular plant, you would look for the presence of fossilized

tracheids.

Hornworts form the sister clade to the

vascular plants.

All of the following are evolutionary adaptations shared by all land plants except

water transport by xylem.