bio test 1

Retention of juvenile body features into sexual maturity is referred to as the presence of __________.

paedomorphosis

A(n) __________ is the smallest unit that can evolve.

population

If the wings of extant flying birds originally arose as thermoregulatory devices in ancestral reptiles, then the bird wings could be accurately described as __________.

exaptations

Single-celled prokaryotes had the Earth to themselves for approximately __________.

1.5 billion years

Which of the following can form entirely new alleles?

Mutation

The early atmosphere may not have been as reducing as originally postulated by Haldane, Oparin, Miller, and Urey. In light of current thinking about the composition of the early atmosphere, what is regarded as a likely place for the abiotic synthesis of organic molecules to have occurred?

Near volcanoes

What were the two major "problems" that had to be solved before plants, animals, and fungi could move into terrestrial habitats?

Reproduction and prevention of dehydration

What evidence most strongly suggests that an impact by an asteroid or meteorite may have caused the extinction of the dinosaurs?

Sedimentary rocks contain a layer of iridium, a mineral uncommon on Earth.

Which of the following is the correct ordering of divisions of the geologic record from largest to smallest?

eon, era, period, epoch

Which of the following is a true statement concerning the history of Earth's biological diversity?

The majority of species that ever lived are now extinct.

What was one ecological change that occurred following the Permian mass extinction?

The percentage of marine predators increased.

In the species selection model, __________ is to macroevolution as __________ is to microevolution.

differential speciation success; differential reproductive success

An important challenge to traditional (pre-1860) ideas about species was the observation that seemingly dissimilar organisms such as hummingbirds, humans, and whales have similar skeletal structures. This most directly suggested to biologists that __________.

dissimilar organisms might have evolved from a distant, common ancestor

Organisms found only in specific places in the world are referred to as __________.

endemic

Stabilizing selection __________.

favors intermediate variants in a population

Fossilized stromatolites __________.

resemble structures formed by bacterial communities that are found today in some warm, shallow, salty bays

The Miller and Urey abiotic synthesis experiment (and subsequent, similar experiments) showed that __________.

simple organic molecules can form spontaneously under conditions like those thought to prevail early in Earth's history

In a population that is in Hardy-Weinberg equilibrium, 64% of the individuals express the recessive phenotype for a particular gene locus. What is the expected frequency of the dominant allele in this population?

0.2

In a population that is in Hardy-Weinberg equilibrium, 64% of the individuals express the recessive phenotype for a particular gene locus. What is the expected frequency of the recessive allele in this population?

0.8

Adaptations are defined as __________.

inherited characteristics of organisms that enhance their survival and reproduction in specific environments

In a certain group of people, 4% are born with sickle-cell disease (homozygous recessive). If this group is in Hardy-Weinberg equilibrium, what percentage of the group is heterozygous for the sickle hemoglobin allele?

32%

A population of zooplankton is exposed to a small number of predatory fish that feed on the larger-sized (adult) zooplankton. Which of the following predictions would most likely occur based on the principles of natural selection?

Adult zooplankton will start to reach sexual maturity when they are still relatively small.

Which of the following statements correctly describe(s) characteristics of genetic drift?

All of the listed responses are correct.

Natural selection leads to adaptation, but there are many organisms on Earth that exhibit characteristics that are less than ideal for their environment. Which of the following statements correctly explain(s) this?

All of the listed responses are correct. Adaptations are often compromises. Selection can act only on existing variations. Chance, natural selection, and the environment interact. Evolution is limited by historical constraints.

During periods of rapid environmental change, what may happen to a species that was well-suited to the former environment?

All of the listed responses are correct. The species may go extinct. Individuals with particular traits that provide an advantage in the new environment will have higher reproductive success. The population may change so much in adapting to the new environment that it is considered a new species. Traits that were favorable in the original environment may be detrimental in the new environment.

Which of the following statements correctly describes a population in Hardy-Weinberg equilibrium?

Allele and genotype frequencies in the population will remain constant from generation to generation.

Which of the following would not have been a consequence of tectonic plate movements bringing previously separated landmasses together in the formation of the supercontinent of Pangaea about 250 million years ago?

Allopatric speciation increased.

Which of the following people developed the idea known as the scala naturae, or scale of nature?

Aristotle

Which type of selection maintains stable frequencies of two or more phenotypic forms in a population?

Balancing selection

Although they originated around 180 million years ago, mammals underwent an adaptive radiation starting approximately 65 million years ago. Why?

Between 180 and 65 million years ago, mammals were outcompeted by the well-established dinosaurs.

The modern idea of extinction as a common occurrence in Earth's history was first proposed in the early 19th century writings of __________.

Cuvier

The original atmosphere of Earth had little oxygen. What was the likely first source of oxygen that led to an oxygen atmosphere?

Cyanobacteria

How did Hutton and Lyell's ideas influence Charles Darwin's thinking?

Darwin reasoned that the Earth must be very old and that slow, subtle processes could produce substantial biological changes.

Antibiotic resistance in bacteria is an example of which of the following?

Directional selection

A population of squirrels is preyed on by small hawks. The smaller squirrels can escape into burrows. The larger squirrels can fight off the hawks. After several generations, the squirrels in the area tend to be very small or very large. What process is responsible for this outcome?

Disruptive selection

Which type of mutation plays the most important role in increasing the number of genes in the gene pool?

Duplication

In the context of populations, how do we define evolution?

Evolution is a change in a population's allele frequencies over generations.

How does our understanding of genetics today refute Lamarck's principle of the inheritance of acquired characteristics?

Experiments in genetics show that traits acquired during an individual's lifetime are not inherited in the way proposed by Lamarck.

Which of the following statements explains why male peacocks with brightly colored feathers are more prevalent than those with plain colors?

Female peacocks choose the showiest males as mates, causing this trait to be more prevalent in the population.

Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.

Genetic drift

Which of the following would seem to be an example of neutral variation?

Human fingerprints

Which of the following is correct regarding natural selection?

If an environment changes, or if individuals move to a new environment, natural selection may result in adaptation to these new conditions, sometimes giving rise to new species. Over time, natural selection can increase the correspondence between organisms and their environments. YOU WERE SURE AND INCORRECT Natural selection is a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than do individuals without those traits. Individuals do not evolve; populations do. All of the listed responses are correct.

Why is the four-stage hypothesis for the abiotic origin of life useful?

It leads to predictions that can be tested.

What insight did Darwin gain from reading Thomas Malthus's essay on human suffering?

Organisms have the capacity to overreproduce.

The correct order of the geologic eras, from most ancient to most recent, is __________.

Paleozoic, Mesozoic, and Cenozoic

Which of the following is not an observation or inference on which natural selection is based?

Poorly adapted individuals never produce offspring.

Why is RNA, rather than DNA, thought to have been the first genetic material?

RNA can also function as a catalyst.

Which of the following sets of conditions is required for Hardy-Weinberg equilibrium?

Random mating, no natural selection, and a large population

Which statement below is true about sexual selection?

Sexual selection can result in sexual dimorphism—marked differences between the sexes in secondary sexual characteristics that are not associated directly with reproduction.

The bacteria Staphylococcus aureus has developed resistance to some antibiotic drugs. How did this resistance come about?

Some members of the bacteria populations possessed some sort of genetic variation for antibiotic resistance that was selected for when the bacteria was exposed to the drugs.

Which of the following is not a unique anatomical feature of mammals that can be recognized in the fossil record?

Temporal fenestra

What does each branch point on an evolutionary tree represent?

The common ancestor of the lineages beginning there and to the right of it

Which of the following is a true statement about the current status of Earth's biodiversity?

The current rate of extinctions is as high as 1,000 times the typical rate seen in the fossil record.

What evidence supports the hypothesis that mitochondria and plastids evolved from prokaryotic endosymbionts?

They have a single circular chromosome similar to bacterial chromosomes; their ribosomes are more like prokaryotic ribosomes than eukaryotic ribosomes

Prior to the Cambrian explosion, all large animals had what characteristic in common?

They were all soft-bodied.

You are watching a movie in which one of the characters excitedly claims to have found human remains in Asia dated at 10 million years old. The date was obtained by carbon-14 dating. What is your reaction?

This can't possibly be true because carbon-14 dating can only be used back to about 75,000 years.

Which of the following is an internal structure that appears in eukaryotic cells and is also present in more ancient prokaryotic cells?

Vesicles

At what level does gene variability quantify genetic variation?

Whole-gene

Which of the following is the best example of gene flow?

Wind blows pollen from one population of plants to another and cross-fertilization occurs.

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of __________.

a change in a developmental gene or in its regulation that altered the spatial organization of body parts

The gene pool of a population consists of __________.

all copies of every type of allele at every locus in all members of the population

The breeding of plants and animals for particular traits by humans is called __________.

artificial selection

The fossil record is __________.

biased in favor of species that existed for a long time

The ratio of carbon-14 to carbon-12 in a fossil can be used to determine the age of the fossil because __________.

carbon-14, unlike carbon-12, decays at a continuous rate after the death of an organism

Even though rodents known as sugar gliders and flying squirrels are members of distinctly different groups of organisms and live on different continents, they possess similar characteristics. This is an example of __________.

convergent evolution

Darwin originally defined evolution as __________.

descent with modification

At the time Darwin voyaged on the HMS Beagle, the popularly accepted theory in Western culture that explained the origin of Earth's plants and animals held that the various species __________.

had been created by divine intervention a few thousand years before

On an evolutionary tree, __________.

homologous characteristics form a nested pattern

Macroevolution differs from microevolution in that macroevolution __________.

includes broad evolutionary changes above the species level

Sexual recombination includes the shuffling of chromosomes in __________ and fertilization.

meiosis

All of the following conditions are required for Hardy-Weinberg equilibrium except __________.

natural selection

Darwin's explanation of how adaptations arise centered on __________.

natural selection

In Darwin's view of descent with modification, __________.

natural selection can improve the match between an organism and its environment

Point mutations in noncoding regions of DNA result in __________.

neutral variation

The amphibians, reptiles, and mammals comprise which group?

tetrapods

Carolus Linnaeus is considered to be the founder of __________, and he __________.

the binomial classification system; thought that resemblances among different species reflected the pattern of their creation

A hurricane hits a small island, killing all but a few members of a bird population. This is an example of __________.

the bottleneck effect

In the Hardy-Weinberg equation, 2pq represents __________.

the expected frequency of the heterozygous genotype

In the Hardy-Weinberg equation, q2 represents __________.

the expected frequency of the homozygous recessive genotype

A storm separates a small number of birds in a migrating population. These birds end up at a destination different from where they usually migrate and establish a new population in this new area. This is an example of __________.

the founder effect

In a large population of randomly breeding organisms, the frequency of a recessive allele is initially 0.3. There is no migration and no selection. Humans enter this ecosystem and selectively hunt individuals showing the dominant trait. When the gene frequency is reexamined at the end of the year, __________.

the frequency of the homozygous dominants will go down, the frequency of the heterozygous genotype will go down, and the frequency of the homozygous recessives will go up

The sickle-cell allele, which is recessive, causes anemia but confers resistance to malaria in individuals who possess it. However, homozygous recessive individuals often die from anemia but not from malaria, and homozygous dominant individuals do not have anemia but could die from malaria. Heterozygous individuals have the highest relative fitness. This is an example of __________.

the heterozygote advantage

No two people are genetically identical, except for identical twins. The main source of genetic variation among human individuals is __________.

the reshuffling of alleles in sexual reproduction

Homologies that appear to have marginal, if any, importance to an organism are called __________.

vestigial structures