Bio Test: Chap. 27-31

Approximately how far back in time does the fossil record extend?

3.5 billion years

If a plant species with 2n = 14 forms an allopolyploid with a plant species with 2n = 18, what would be the likely diploid (2n) number of the allopolyploid?

32

How can mass extinction events be distinguished from background extinctions?

A mass extinction occurs when at least 60 percent of species are wiped out within 1 million years.

Which statement is correct?

A synapomorphy may arise due to convergent evolution.

Which of the following statements explains why animals are less likely than plants to speciate by polyploidy?

Animals self-fertilize less often than plants, so diploid gametes are less likely to fuse.

A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification?

Archaea

Which character separates bacteria from archaea

Bacteria have peptidoglycan in their cell wall.

While examining a rock surface, you have discovered an interesting new organism. Which of the following criteria will allow you to classify the organism as belonging to Bacteria but not Archaea or Eukarya

Cell walls are made primarily of peptidoglycan.

If autopolyploidy is responsible for the formation of a tetraploid grape (with extra-large fruit) from a diploid population (with smaller fruit), which of the following events must have occurred?

Doubling of chromosome number in the diploid population

How do lizard species on mainland California compare in diversity to those found on islands?

Due to more open ecological opportunities on a given island, greater differences occur between island species.

Which is strong evidence supporting the impact hypothesis for the extinction of the dinosaurs?

Extremely high quantities of iridium in rocks that formed around 65 million years ago

Why is bipedalism considered a synapomorphy for hominins (the group that includes humans)?

Hominins are the only mammal group to walk on two legs.

Which of the following statements about species, as defined by the biological species concept, is (are) correct? I. Biological species are defined by reproductive isolation. II. Biological species are the model used for grouping extinct forms of life. III. All members of a species can potentially interbreed.

I and III

Which of the following would be useful in creating a phylogenetic tree of a taxon? I) morphological data from fossil species II) genetic sequences from living species III) behavioral data from living species

I, II, and III

Which of the following statements is true about a phylogeny, as represented by a phylogenetic tree? I) Descendant groups (branches) from the same node do not necessarily share any derived characters. II) A monophyletic group can be properly based on convergent features. III) The ancestral group often has all the synapomorphies of the descendant species.

None. Not I, II, or III.

What distinguishes bacteria from archaea?

Only bacteria have peptidoglycan in their cell walls.

Why is speciation by polyploidy more likely in plants than in animals?

Plant gametes can be produced by meiosis from somatic cells that have undergone many rounds of mitosis.

The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France across central Europe to Russia. Both male and female hybrids exist, but when they mate among themselves, they are rarely successful in producing offspring. What can you infer from this information?

Postzygotic isolation exists between the two frog species.

Which of the following statements best describes the rationale for applying the principle of parsimony in constructing phylogenetic trees?

Similarity due to common ancestry should be more common than similarity due to convergent evolution.

Which statement about polyploidy is correct?

Speciation by polyploidy may be almost instantaneous.

Which of the situations below describes vicariance?

The Grand Canyon forms, separating two populations of squirrels on the North rim and the South rim.

How do autopolyploidy and allopolyploidy differ?

The chromosomes of an autopolyploid individual come from the same species, while an allopolyploid individual has sets of chromosomes from different species

Which of the following is true of all horizontally oriented phylogenetic trees, where time advances to the right?

The common ancestor represented by a branch point farther right existed more recently in time than the common ancestors represented at branch points located farther to the left.

What is the best evidence that all life evolved from prokaryotic rather than eukaryotic ancestors?

The oldest fossil form of life known is prokaryotic.

Part A Which is strong evidence that similar traits in different evolutionary lineages are the result of homology and not homoplasy?

The traits are also found in many intervening lineages on the tree of life.

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification?

The two forms interbreed often in nature, and their offspring have good survival and reproduction.

Members of two different species possess a similar-looking structure that they use in a similar way to perform about the same function. Which of the following would suggest that the relationship more likely represents homology instead of convergent evolution?

The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical.

Many songbirds breed in North America in the spring and summer and then migrate to Central and South America in the fall. They spend the winter in these warmer areas, where they feed and prepare for the spring migration north and another breeding season. Two hypothetical species of sparrow, A and B, overwinter together in mixed flocks in Costa Rica. In spring, species A goes to the east coast of North America, and species B goes to the west coast. What can you say about the isolating mechanisms of these two species?

Their winter habitat has no bearing on their degree of reproductive isolation.

Why do mass extinctions wipe out species more or less randomly?

They are caused by exceptionally harsh, short-term conditions.

How might paleontologists be misled by their observations of fossils?

They typically only find species that were widespread and/or present on the Earth for long periods of time.

There is an island in the middle of a large river that houses a large population of ants. Damming of the river causes the island to flood and only the highest points of the island are now above water. The ants cannot swim, so are now in multiple isolated populations. Which of the following best describes this event?

This situation represents isolation by vicariance.

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?

a behavioral reproductive isolating mechanism

The largest unit within which gene flow can readily occur is _____.

a species

Ichthyosaurs, now extinct, were aquatic reptiles with dorsal fins and tails, like fish. Their most recent ancestors were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are _____.

adaptations to a common environment and examples of convergent evolution

House finches were found only in western North America until 1939, when a few individuals were released in New York City. These individuals established a breeding population and gradually expanded their range. The western population also expanded its range somewhat eastward, and the two populations have recently come in contact. If the two forms were unable to interbreed when their expanding ranges met, it would be an example of _____.

allopatric speciation

How are two different species most likely to evolve from one ancestral species?

allopatrically, after the ancestral species has split into two populations

Which of the following groups of organisms is among the most abundant on Earth?

bacteria

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?

behavioral isolation

On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. Which type of reproductive isolation operates to keep the mosquitofish isolated, even when fish from different ponds are reunited in the same body of water?

behavioral isolation

Which of the following is an example of homoplasy?

cell walls in plants and fungi

To apply parsimony to constructing a phylogenetic tree, _____.

choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology

Some beetles and flies have antler-like structures on their heads, much like male deer do. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of _____.

convergent evolution

Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appearance is intermediate between the two parents. These offspring will breed with each other or with birds from either parent population, and all offspring of these pairings appear intermediate to various degrees. The two populations are _____.

different subspecies, under the morphological species concept

A researcher notices that in a certain moth species, some females prefer to feed and lay eggs on domesticated solanaceous plants like potatoes and tomatoes. Other females prefer to feed and lay eggs on wild solanaceous plants like Datura. Both male and female moths primarily use scent to find these plants from afar. Females tend to mate where they feed, and the researcher finds a genetic basis for scent preference in these moths. Based on the above information, what might be occurring in this moth species?

divergence in sympatry

You need to identify the major type of bacteria living on the shower curtain in your bathroom and find out what they use as a food source. What is the most efficient method for answering this question?

enrichment culture

Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. Pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species. These two juniper species are kept separate by _____.

gametic isolation

What does the biological species concept use as the primary criterion for determining species boundaries?

gene flow

Which of the following does not tend to promote speciation?

gene flow

In plant communities today, leaf morphology is correlated with mean annual temperature, so paleobotanists use fossil leaf morphology to estimate the mean annual temperature of paleoclimates. However, the angiosperm fossil record contains an overabundance of samples fossilized near lakes or rivers where vines are especially common. Since vine leaves have a somewhat different association with temperature, use of data from vine-rich locations leads to mean average temperature estimates that are lower than actual recorded temperatures in modern plant communities. This potential bias in paleobotanical climate estimates is due to which type of bias in the fossil record?

habitat bias

Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appearance is intermediate between the two parents. These offspring will breed with each other or with birds from either parent population, and all offspring of these pairings appear intermediate to various degrees. What keeps the two populations separate?

habitat isolation

Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals?

homologous; analogous

If, someday, an archaean cell is discovered whose rRNA sequence is more similar to that of humans than the sequence of mouse rRNA is to that of humans, the best explanation for this apparent discrepancy would be _____.

homoplasy

Which of the following traits do archaeans and bacteria share

lack of a nuclear envelope and presence of plasma membrane

The approach to estimating phylogenetic trees is most like the approach of which species concept?

phylogenetic species concept

Which is the first step in allopatric speciation?

physical isolation of two populations

Most causes of speciation are relatively slow, in that they may take many generations to see changes, with the exception of _____.

polyploidy

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). If the molecular data best reflect the evolutionary history of these two groups, then the morphological similarities of these two species is most likely due to _____.

possession of analogous (convergent) traits

The best classification system is that which most closely _____.

reflects evolutionary history

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology? Dogs and wolves _____.

share a very recent common ancestor

Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species?

sympatric speciation and polyploidy

Beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it?

sympatric speciation; habitat differentiation

A small number of birds arrive on an island from a neighboring larger island. This small population begins to adapt to the new food plants available on the island, and their beaks begin to change. About twice a year, one or two more birds from the neighboring island arrive. These new arrivals _____.

tend to retard adaptation to the new food plants

About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting North and South America) formed, dividing marine organisms into Pacific and Caribbean populations. Researchers have examined species of snapping shrimp on both sides of the isthmus. Based on the morphological species concept, there appeared to be seven pairs of species, with one species of each pair in the Pacific and the other in the Caribbean. The different species pairs live at somewhat different depths in the ocean. Using mitochondrial DNA sequences, the researchers estimated phylogenies and found that each of these species pairs, separated by the isthmus, were indeed each other's closest relatives. The researchers investigated mating in the lab and found that many species pairs were not very interested in courting with each other, and any that did mate almost never produced fertile offspring. (N. Knowlton, L. A. Weigt, L. A. Solorzano, D. K. Mills, and E. Bermingham. 1993. Divergence in proteins, mitochondrial DNA, and reproductive incompatibility across the Isthmus of Panama. Science 260:1629-32.) Refer to the paragraph about the formation of the Isthmus of Panama. The sister populations on opposite sides of the isthmus are true species under which species concept?

the morpholoogical species, biological species, and phylogenetic species concepts

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily?

to serve as an outgroup