Exam 29: Plant Diversity I: How Plants Colonized Land

Which of the following were probably factors that permitted early plants to successfully colonize land? 1)the relative number of potential predators (herbivores) 2)the relative number of competitors 3)the relative availability of symbiotic partners 4)air's relative lack of support,compared to water's support

During glacial periods in the early evolution of land plants,which of the following would have been a beneficial adaptation regarding the number of stomata per unit surface area,and what accounts for it?

Increasing the number of stomata per unit surface area of a leaf when atmospheric CO₂ levels decline is most analogous to a human

Liverworts,hornworts,and mosses are grouped together as the Bryophytes.Besides not having vascular tissue,what do they all have in common?

What is a key difference between spores and seeds?

Stomata ________.

As is true of the gametophytes of all land plants,the gametophytes of true mosses lack stomata.Yet,the feather moss Pleurozium harbors nitrogen-fixing cyanobacteria.Which of the following is a feature of moss gametophytes that is most important for the continued survival of these cyanobacteria in the tissues of the feather moss gametophyte?

All of the following are common to both charophytes and land plants except

The next few questions are based on the following description. A biology student hiking in a forest happens upon an erect,15-cm-tall plant that bears microphylls and a strobilus at its tallest point.When disturbed,the cone emits a dense cloud of brownish dust.A pocket magnifying glass reveals the dust to be composed of tiny spheres with a high oil content. -A dissection of the interior of this organism's stem should reveal

Which taxon is essentially equivalent to the "embryophytes"?

Sporophylls can be found in which of the following?

You are hiking in a forest and happen upon a plant featuring a central stemlike structure from which sprout many,tiny,leaflike structures.Which of the following would be the most certain means of distinguishing whether it was a true moss or a club moss?

At some time during their existence,bryophytes may feature

Which of these time intervals,based on plant fossils,came last (most recently)?

If intelligent extraterrestrials visited Earth 475 million years ago,and then again 300 million years ago (at the close of the Carboniferous period),what trends would they have noticed in Earth's terrestrial vegetation over this period? 1)a trend from dominant gametophytes to dominant sporophytes 2)a trend from sporangia borne on modified leaves (sporophylls)to sporangia borne on stalks (seta) 3)a trend from no true leaves,to microphylls,to megaphylls 4)a trend from soil-surface-hugging plants to "overtopping" plants 5)a trend toward increased lignification of conducting systems

Which of the following structures are in the gametophyte generation of a moss?

In terms of evolutionary time,which phyla are the oldest and which are the most recent (respectively)?

Use the following figure to answer the questions below. -What is true of the phylogenetic tree in the figure above? 1)It depicts uncertainty about whether the bryophytes or the vascular plants evolved first. 2)It is hypothetical. 3)It includes polytomies. 4)It shows that ferns (phylum Pterophyta)are the closest living relatives to the seed plants. 5)It indicates that seeds are a shared ancestral character of all vascular plants.

A student encounters a pondweed which,judging from its appearance,seems to be a charophyte.She brings a sample back to her biology lab.Using only a compound light microscope to study the sample,which of the following features should help her to determine whether the sample comes from a charophyte or from some other type of green alga? 1)molecular structure of enzymes inside peroxisomes 2)structure of sperm cells 3)presence of phragmoplasts 4)rings of cellulose-synthesizing complexes

Evidence indicates that plants increase the number of stomata in their leaves as atmospheric CO₂ levels decline.Increasing the number of stomata per unit surface area should have the effect of doing which of the following? 1)increase dehydration of leaf tissues 2)decrease dehydration of leaf tissues 3)counter the effect of declining CO₂ on photosynthesis 4)reinforce the effect of declining CO₂ on photosynthesis 5)decrease the O₂ content of air next to the leaves to a level lower than it would otherwise be 6)increase the O₂ content of air next to the leaves to a level higher than it would otherwise be