Ch 27 Learning Curve

Plants started growing on land approximately

450 million years ago.

What is a monilophyte?

A clade of seedless vascular plants that includes ferns and horsetails

Which synapomorphies support stoneworts as the closest sister group of land plants?

Branching and apical growth

Which of the nonvascular plant clades has the highest number of extant species?

Bryophyta (mosses)

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?

Efficient growing facilities have already been established.

Which is the correct order of appearance of features during plant evolution?

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

Which statement about plant life cycles is true?

Homosporous plants evolved before heterosporous plants.

Where on a fern plant would you look to find spores?

In clusters of sporangia in sori on the sporophyte leaf

Which characteristic of nonvascular plants has restricted their expansion on land to moist areas?

Lack of true roots

Which living group was the earliest to evolutionarily diverge from all other living vascular plants?

Lycophytes (club mosses, spike mosses, and quillworts)

The hornworts are the sister taxon of which other land plant clade(s)?

Lycophytes, horsetails, ferns, and seed plants

True roots are a synapomorphy of which of the following groups of plants?

Lycophytes, monilophytes, seed plants

Which set of clades correctly describes the tracheophytes?

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

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

Microphylls

The organism shown is thought to be similar in form to the ancestor of the Plantae. With this in mind, which description best summarizes the ancestor of plants?

Primary endosymbiosis by a unicellular eukaryote resulted in the engulfment of a photosynthetic bacterium that over time became the chloroplast.

Which structure in land plants is diploid?

Sporangium

Which statement provides the most accurate description of the structures shown in the figure?

These structures contain small, lens-shaped outgrowths that are capable of asexually propagating liverworts.

Coleochaetophytes have all of the following synapomorphies in common with stoneworts except

apical growth.

Algae

are aquatic photosynthetic eukaryotes.

In nonvascular plants, the _______ is photosynthetic and is _______ independent of the _______.

gametophyte; nutritionally; sporophyte

An antheridium is _______ and produces _______.

haploid; sperm

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

hornwort

Microphylls differ from megaphylls in that

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

A megasporangium has the same relationship to a megaspore as a microsporangium has to a

microspore

Plant gametophytes divide by _______ to produce gametes, while sporophytes produce spores through _______.

mitosis; meiosis

The primary endosymbiosis of a cyanobacterium by an early eukaryotic cell that led to evolution of plants occurred

more than a billion years ago.

Liverworts, hornworts, and mosses are found on all seven continents. Their survival in harsh environments is aided by

mycorrhizae.

Growth of red algae in deep water is most limited by

penetration of light through the water.

The red color present in red algae is primarily due to the accessory pigment

phycoerythrin

The cuticle was one of the most important adaptations to life on land for plants because it

protected the plant from desiccation.

Hornworts can be distinguished from the other nonvascular plants by their

single chloroplast per cell and persistently green sporophyte.

Heterospory in a plant life cycle is characterized by two different kinds of

spores that mature into two different kinds of gametophytes.

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

Land plants are often called embryophytes because

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

the presence of a nutritionally independent sporophyte.

Soil formation on the early land masses was not helped by

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

thick spore walls to prevent dessication.

The common ancestor of vascular plants had

tracheids

Xylem and phloem are both types of

vascular tissue.

The earliest clades of photosynthetic eukaryotes that led to land plants

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