Chapter 27

Scientists have recently begun exploring green algae as a source of biofuels. Which is not a reason these photosynthetic eukaryotes are attractive targets for petroleum production? A. Efficient growing facilities have already been established. B. Algae can use wastewater as a source of nutrients, providing a dual benefit of biofuel production and water remediation. C. The use of algae is sustainable. D. Algae can remove CO2 from the atmosphere, reducing the amount of greenhouse gas present in the air. E. Most of the petroleum from the ocean depths originated from photosynthetic eukaryotes.

A. Efficient growing facilities have already been established.

True roots are a synapomorphy of which of the following groups of plants? A. Lycophytes, monilophytes, seed plants B. Bryophyta, hepatophyta, anthocerophyta C. Rhyniophytes, bryophyta, lycophytes D. Streptophytes, lycophytes, monilophytes E. Rhyniophytes, lycophytes, monilophytes, seed plants

A. Lycophytes, monilophytes, seed plants

Which structure in land plants is diploid? A. Sporangium B. Gamete C. Gametangium D. Spore E. Gametophyte

A. Sporangium

Which is the correct order of development in a moss gametophyte? A. Spore, branched filamentous protonema, bud, spiral leafy gametophyte, gametangia B. Spiral leafy gametophyte, spore, bud, branched filamentous protonema, gametangia C. Spore, bud, branched filamentous protonema, spiral leafy gametophyte, gametangia D. Gametangia, spore, branched filamentous protonema, bud, spiral leafy gametophyte E. Spore, spiral leafy gametophyte, branched filamentous protonema, bud, gametangia

A. Spore, branched filamentous protonema, bud, spiral leafy gametophyte, gametangia

Dichotomous branching happens when A. a shoot tip divides and grows into two equal branches. B. a phylum diverges from a common ancestor. C. a shoot tip automatically divides. D. one plant grows taller than another. E. branches divide.

A. a shoot tip divides and grows into two equal branches.

Algae A. are aquatic photosynthetic eukaryotes. B. contain phycoerythrin in their cell walls. c. were the earliest land plants. D. protect their embryos. E. are also known as streptophytes.

A. are aquatic photosynthetic eukaryotes.

Stomata function to A. control the entry and exit of O2, CO2, and water vapor from the plant surface. B. prevent light from penetrating the plant surface. C. control the release of spores from the sporophyte. D. prevent CO2 loss from the plant surface. E. control the entry and exit of nutrients from the plant surface.

A. control the entry and exit of O2, CO2, and water vapor from the plant surface.

Specialized reproductive organs on the gametophyte are _______ that produce _______ by _______. A. gametangia; gametes; mitosis B. embryos; zygotes; fertilization C. gametangia; spores; meiosis D. sporangia; spores; meiosis E. sporangia; spores; mitosis

A. gametangia; gametes; mitosis

Chlorophytes A. include both unicellular and multicellular forms. B. are limited to fresh water. C. contain the pigment phycoerythrin. D. are under 10 cm in size. E. make up the smallest clade of green algae.

A. include both unicellular and multicellular forms.

The primary endosymbiosis of a cyanobacterium by an early eukaryotic cell that led to evolution of plants occurred A. more than a billion years ago. B. approximately 400 million years ago. C. approximately 400,000 years ago. D. approximately 4,000 years ago. E. approximately 400 years ago.

A. more than a billion years ago

A(n) _______ is defined as a shared derived trait. A. synapomorphy B. plasmodesmata C. apomorphy D. synapophyte E. plesiomorphy

A. synapomorphy

Soil formation on the early land masses was not helped by A. the products of photosynthesis. B. decomposition of plants. C. mycorrhizae. D. growth of early land plants. E. acids secreted by plants.

A. the products of photosynthesis.

Despite lacking tracheids, nonvascular plants possess structures or characteristics that allow them to obtain and transport water and minerals on land. These include all of the following except A. thick spore walls to prevent dessication. B. small size, which allows minerals to be distributed evenly by diffusion. C. growth in dense masses through which water can move by capillary action. D. cells specialized for water transport. E. association with mycorrhizae—fungi that form a mutualistic partnership with plants.

A. thick spore walls to prevent dessication.

The nonvascular plant that could most easily spread and form a larger colony is one with a sporophyte that has a sporangium A. with a long stalk and a mechanism to throw its spores. B. that is close to the ground and produces sperm with flagella. C. with a long stalk and that produces sperm with flagella. D. that is close to the ground and has a mechanism to throw its spores. E. with a long stalk and that rots to release spores.

A. with a long stalk and a mechanism to throw its spores.

Plants started growing on land approximately A. 4.5 billion years ago. B. 450 million years ago. C. 450,000 years ago. D. 4,500 years ago. E. 450 years ago.

B. 450 million years ago.

What feature is common to hydroids and tracheids? A. Both are found in vascular plants. B. Both conduct water. C. Both conduct water and sugars. D. Both are found in nonvascular plants. E. Both have lignin in their cell walls.

B. Both conduct water.

Which statement about plant life cycles is true? A. Heterosporous gametophytes each have both male (antheridia) and female (archegonia) sex organs. B. Homosporous plants evolved before heterosporous plants. C. There is one heterosporous common ancestor for all heterosporous plant lineages, but homospory evolved multiple times in different lineages. D. Homosporous plants produce one kind of sporophyte, and heterosporous plants produce two kinds of sporophytes. E. A heterosporous plant produces two kinds of spores that each develop into a homosporous plant.

B. Homosporous plants evolved before heterosporous plants.

Which structure in land plants is haploid? A. Multicellular sporophyte B. Multicellular gametophyte C. Zygote D. Sporangium E. Embryo

B. Multicellular gametophyte

Homosporous plants bear a single type of spore that gives rise to one type of gametophyte. Heterosporous plants produce two types of spores resulting in two distinct gametophytes—one male and one female. What is a plausible explanation for the evolution of separate male and female gametophytes in heterosporous plants? A. Consolidating male and female gametes on a single plant shortens generation times by reducing the distance sperm travel to fuse with the egg, thus allowing for faster rates of evolution. B. Separating male and female gametophytes promotes outcrossing and results in greater genetic diversity of offspring. C. Separating male and female gametophytes prevents dessication. D. Consolidating male and female gametes on a single plant ensures close proximity of gametes during mating. E. Separating male and female gametophytes reduces the risk of being eliminated by predation.

B. Separating male and female gametophytes promotes outcrossing and results in greater genetic diversity of offspring.

Which statement best describes the hypothesis for why high atmospheric CO2 limited evolution of large megaphylls? A. Large leaves captured too much light compared with the amount of CO2 they could take up, so they stayed small to avoid light. B. With high CO2, fewer stomata were needed, so the plants had less capacity for evaporative cooling of large leaves. C. With high CO2, more stomata were needed, so the plants with large leaves lost too much water. D. High CO2 caused too much damage to plants with large leaves, because of suffocation. E. The CO2 caused global warming, shading the plants and limiting plant growth capacity.

B. With high CO2, fewer stomata were needed, so the plants had less capacity for evaporative cooling of large leaves.

Spores in land plants are A. diploid and are produced on the sporophyte. B. haploid and are produced on the sporophyte. C. diploid and are produced on the gametophyte. D. diploid and are produced by fusion of haploid gametes. E. haploid and are produced on the gametophyte.

B. haploid and are produced on the sporophyte.

All of the following were environmental challenges to plants moving onto land except A. the pull of gravity. B. low light conditions. C. the availability of nutrients. D. a lack of water for dispersal of gametes. E. desiccation.

B. low light conditions.

Specialized reproductive organs on the sporophyte are _______ that produce _______ by _______. A. gametangia; zygotes; fertilization B. sporangia; spores; meiosis C. sporangia; spores; mitosis D. embryos; zygotes; fertilization E. gametangia; gametes; meiosis

B. sporangia; spores; meiosis

What is a monilophyte? A. A clade of plants that have microphylls and dichotomous branching B. A clade of plants with a small leaf with one vascular strand C. A clade of seedless vascular plants that includes ferns and horsetails D. A clade of seed-bearing vascular plants that includes lycophytes and ferns E. A sister group to the lycophytes

C. A clade of seedless vascular plants that includes ferns and horsetails

Which of the land plant groups is considered to be the sister group of all the others? . A. Flowering plants B. Mosses C. Liverworts D. Tracheophytes E. Hornworts

C. Liverworts

Which set of clades correctly describes the nonvascular land plants? A. Liverworts, mosses, hornworts, lycophytes, horsetails, and ferns B. Lycophytes, horsetails, ferns, cycads, ginkgo, gnetophytes, conifers, and flowering plants C. Liverworts, mosses, and hornworts D. Lycophytes, horsetails, and ferns E. Cycads, ginkgo, gnetophytes, conifers, and flowering plants

C. Liverworts, mosses, and hornworts

Which statement about alternation of generations in land plants is true? A. The sporophyte produces haploid spores by mitosis. B. Spores germinate and divide by mitosis to form the diploid sporophyte. C. The gametophyte produces haploid gametes by mitosis. D. The haploid zygote divides by mitosis to form the gametophyte. E. Diploid gametes fuse to form a zygote.

C. The gametophyte produces haploid gametes by mitosis.

A strobilus is A. the arrangement of microphylls around the stem of a lycophyte. B. a terminal sporangium. C. a cluster of spore-bearing microphylls. D. the branch point of a lycophyte stem. E. a cluster of rootlike rhizoids.

C. a cluster of spore-bearing microphylls.

Megaphyll size increased as _______ on Earth. A. atmospheric NO2 decreased B. atmospheric NO2 increased C. atmospheric CO2 decreased D. atmospheric CO2 increased E. solar radiation increased

C. atmospheric CO2 decreased

In nonvascular plants, the _______ is photosynthetic and is _______ independent of the _______. A. sporophyte; reproductively; gametophyte B. sporophyte; structurally; gametophyte C. gametophyte; nutritionally; sporophyte D. sporophyte; nutritionally; gametophyte E. gametophyte; reproductively; sporophyte

C. gametophyte; nutritionally; sporophyte

Microphylls differ from megaphylls in that A. microphylls evolved before stomata, and megaphylls evolved after stomata. B. microphylls are thought to have evolved from small flaps of photosynthetic tissue between branches, whereas megaphylls evolved from large flaps of tissue between branches. C. microphylls are thought to have evolved from sterile sporangia, whereas megaphylls evolved from modified branches. D. microphylls have small xylem cells in their vascular tissue, whereas megaphylls have large xylem cells. E. microphylls are derived from female tissues, and megaphylls are derived from male tissues.

C. microphylls are thought to have evolved from sterile sporangia, whereas megaphylls evolved from modified branches.

Heterospory in a plant life cycle is characterized by two different kinds of A. spores that fuse into a zygote that matures into a single kind of gametophyte. B. gametophytes that make two different kinds of spores. C. spores that mature into two different kinds of gametophytes. D. gametes made by a single kind of gametophyte. E. sporophytes that make two different kinds of gametes.

C. spores that mature into two different kinds of gametophytes.

The common ancestor of vascular plants had A. flowers. B. megaphylls. C. tracheids. D. seeds. E. microphylls.

C. tracheids.

A euphyllophyte is defined as a plant with A. overtopping roots. B. true microphylls. C. true leaves. D. true roots. E. dichotomous stems.

C. true leaves

What effect does having a basal region of cell division have on sporophyte function in hornworts? A. It provides places for symbiotic nitrogen-fixing bacteria to live. B. It limits cell division to the base in sporophytes, so they do not get as tall as those of moss and liverworts. C. It helps raise the spores so they can be more easily dispersed by symbiotic fungi. D. It allows spores to be continually made and released as long as the sporophytes live. E. It keeps making green tissue to support growth of the gametophytes.

D. It allows spores to be continually made and released as long as the sporophytes live.

The hornworts are the sister taxon of which other land plant clade(s)? A. Lycophytes, horsetails, and ferns B. Liverworts, mosses, and seed plants C. Seed plants D. Lycophytes, horsetails, ferns, and seed plants E. Liverworts and mosses

D. Lycophytes, horsetails, ferns, and seed plants

Which set of clades correctly describes the tracheophytes? A. Hepatophyta, bryophyta, anthocerophyta, lycopodiophyta, and monilophyta B. Hepatophyta, bryophyta, and anthocerophyta C. Cycadophyta, ginkgophyta, gnetophyta, coniferophyta, and angiosperms D. Lycopodiophyta, monilophyta, cycadophyta, ginkgophyta, gnetophyta, coniferophyta, and angiosperms E. Anthocerophyta, gymnosperms, and angiosperms

D. Lycopodiophyta, monilophyta, cycadophyta, ginkgophyta, gnetophyta, coniferophyta, and angiosperms

Why is liquid water required for sexual reproduction in mosses? A. The egg would desiccate without it. B. They have spores with a thick coat. C. The gametophytes would desiccate without it. D. They have sperm with flagella. E. Embryos require water to grow.

D. They have sperm with flagella.

With regard to the life cycles observed in plants and animals, the two groups share the similarity of A. a generation of multicellular haploid individuals. B. gametes produced by the multicellular haploid generation. C. gametes produced by the unicellular diploid generation. D. a generation of multicellular diploid individuals. E. gametes produced by meiosis.

D. a generation of multicellular diploid individuals

Coleochaetophytes have all of the following synapomorphies in common with stoneworts except A. multicellularity. B. retention of egg on parental tissue. C. features of cytokinesis. D. apical growth. E. plasmodesmata.

D. apical growth.

Hornworts can be distinguished from the other nonvascular plants by their A. internal cavity of mucilage and persistently green gametophyte. B. internal cavity of mucilage and multiple chloroplasts per cell. C. multiple chloroplasts per cell and persistently green sporophyte. D. single chloroplast per cell and persistently green sporophyte. E. persistently green gametophyte and single chloroplast per cell.

D. single chloroplast per cell and persistently green sporophyte.

Which part of the moss life cycle is paired with an incorrect description? A. Embryo: early stage of sporophyte development B. Antheridium: specialized organ on the gametophyte that produces sperm C. Rhizoid: part of the developing gametophyte D. Protonema: early stage of gametophyte development E. Archegonium: specialized organ on the gametophyte that produces spores

E. Archegonium: specialized organ on the gametophyte that produces spores

Which synapomorphies support stoneworts as the closest sister group of land plants? A. Plasmodesmata and gene sequence similarity B. Retention of egg on parental tissue, plasmodesmata, branching, and apical growth C. Retention of egg on parental tissue, details of mitosis and cytokinesis, and plasmodesmata D. Retention of egg on parental tissue and gene sequence similarity E. Branching and apical growth

E. Branching and apical growth

Which is the correct order of appearance of features during plant evolution? A. Heterospory, endosymbiotic chloroplasts, retention of egg on parental tissue, protected embryo, stomata, tracheids, megaphylls B. Endosymbiotic chloroplasts, retention of egg on parental tissue, protected embryo, tracheids, megaphylls, stomata, heterospory C. Endosymbiotic chloroplasts, protected embryo, retention of egg on parental tissue, stomata, tracheids, megaphylls, heterospory D. Retention of egg on parental tissue, endosymbiotic chloroplasts, protected embryo, stomata, tracheids, megaphylls, tracheids, heterospory E. Endosymbiotic chloroplasts, retention of egg on parental tissue, protected embryo, stomata, tracheids, megaphylls, heterospory

E. Endosymbiotic chloroplasts, retention of egg on parental tissue, protected embryo, stomata, tracheids, megaphylls, heterospory

Which characteristic of nonvascular plants has restricted their expansion on land to moist areas? A. Layers of maternal tissue that protect the embryo B. Cuticle C. Small size D. Matted growth form E. Lack of true roots

E. Lack of true roots

Two hallmarks of a life cycle with an alternation of generations are A. a multicellular diploid stage and unicellular haploid stage, and gametes that are produced by meiosis. B. a unicellular diploid stage and multicellular haploid stage, and gametes that are produced by mitosis. C. a multicellular diploid stage and unicellular haploid stage, and gametes that are produced by mitosis. D. a multicellular diploid stage and multicellular haploid stage, and gametes that are produced by meiosis. E. a multicellular diploid stage and multicellular haploid stage, and gametes that are produced by mitosis.

E. a multicellular diploid stage and multicellular haploid stage, and gametes that are produced by mitosis.

The lycophyte group of plants includes A. horsetails and ferns. B. rhyniophytes, monilophytes, and club mosses. C. club mosses, ferns, and horsetails. D. spike mosses and quillworts. E. club mosses, spike mosses, and quillworts.

E. club mosses, spike mosses, and quillworts.

An antheridium is _______ and produces _______. A. diploid; sperm B. haploid; an egg C. diploid; spores D. haploid; spores E. haploid; sperm

E. haploid; sperm

Rhyniophytes were characterized by A. dichotomously branching aerial stems, extensive roots, and sporangia. B. aerial stems with sporangia, rhizomes, and dichotomously branching rhizoids. C. dichotomously branching aerial stems, extensive roots, vascular tissue, and sporangia. D. aerial stems with vascular tissue, nonvascular rhizomes, and extensive roots. E. horizontal rhizomes, rhizoids, dichotomously branching aerial stems, and sporangia.

E. horizontal rhizomes, rhizoids, dichotomously branching aerial stems, and sporangia.

Plant gametophytes divide by _______ to produce gametes, while sporophytes produce spores through _______. A. mitosis; cytokinesis B. embryogenesis; fertilization C. meiosis; differentiation D. meiosis; fertilization E. mitosis; meiosis

E. mitosis; meiosis

Growth of red algae in deep water is most limited by A. concentration of salt in the water. B. available substrate for holdfasts. C. competition with other algae. D. temperature. E. penetration of light through the water.

E. penetration of light through the water.

Land plants are often called embryophytes because A. they have small embryos. B. the fertilized egg develops into an embryo. C. they have a chemical affinity for embryos. D. there is a distinct embryo stage of development. E. the embryo is protected by the parent plant.

E. the embryo is protected by the parent plant.

The feature that distinguishes hornworts as more closely related to vascular plants than mosses or liverworts is A. the use of starch as a storage molecule for sugar. B. the presence of rudimentary water-conducting elements. C. the separation of male and female gametophytes. D. the ability to grow without a set limit. E. the presence of a nutritionally independent sporophyte.

E. the presence of a nutritionally independent sporophyte.

In the fern life cycle, A. the gametophyte is larger and longer-lived than the sporophyte. B. the mature sporophyte and gametophyte are mutually nutritionally dependent. C. the mature sporophyte is dependent on the gametophyte. D. the mature gametophyte is nutritionally dependent on the sporophyte. E. the sporophyte is larger and longer-lived than the gametophyte.

E. the sporophyte is larger and longer-lived than the gametophyte.

Sporophytes and gametophytes differ from each other genetically because A. gametophytes are evolutionarily more ancient than sporophytes, so their sequences have diverged. B. mitosis produces the gametes in plants, but meiosis produces gametes in animals. C. mitosis leads to larger gametophytes than sporophytes in mosses but to larger sporophytes than gametophytes in ferns. D. the chromosomes in the spores come from both parents, but the gametes only have one set of chromosomes. E. the sporophytes have one set of chromosomes from each parent, while gametophytes have only one set of chromosomes.

E. the sporophytes have one set of chromosomes from each parent, while gametophytes have only one set of chromosomes.

The earliest clades of photosynthetic eukaryotes that led to land plants A. used starch as a carbohydrate storage molecule. B. share the derived trait of having peptidoglycan in their chloroplasts. C. used phycoerythrin instead of chlorophyll a to harvest light. D. colonized land, helping animals and fungi evolve on land. E. were similar to the modern glaucophytes, red algae, and chlorophytes.

E. were similar to the modern glaucophytes, red algae, and chlorophytes.

Despite being the largest clade of green algae, _______ are not believed to have given rise to land plants.

chlorophytes

Structures found in individuals with a _______ life cycle include microgametophytes and megagametophytes.

heterosporous

Unlike the other groups of nonvascular plants, the _______ sporophyte has no stalk and is persistently green—a trait shared with vascular plants.

hornwort

You recover a fossil from the Devonian period that appears to be a large sporophyte with a stem that grows in segments above whorls of true leaves. Based on this description, you identify the specimen as a _______, which is one member of a clade containing only itself and ferns.

horsetail

Hydrocarbons play two roles in algae: an energy reserve and a way to increase bouancy. The latter is important because it maximizes exposure to _______, providing energy for the algae to fix CO2.

light

Though _______ contain true roots, they differ from other members of the tracheophytes because of the arrangement of their vasculature.

lycophytes

_______ are believed to have evolved from sterile sporangia. Evidence that supports this claim includes the organization of the vasculature found in these structures.

microphylls

In recent years, atmospheric levels of CO2 have increased and resulted in a global temperature change. With regard to leaf structure, this increase in CO2 could mean less selective pressure for _______, which would ultimately drive selection for a reduction in leaf area.

stomata