Chapter 13 – Bio 101 – Flashcards

Some of your DNA may not code for any protein and has no known function in gene regulation; it is sometimes referred to as "junk" DNA. How do nucleotide sequences of "junk DNA" evolve? They evolve through natural selection. They evolve by gradually being eliminated from the gene pool. They evolve through genetic drift and other chance processes. They evolve to be more useful by taking on new functions.

In populations of the greater prairie chicken in Illinois, genetic diversity was lost through genetic drift and restored by gene flow. lost through gene flow and restored by mutation. lost through mutation and restored by natural selection. lost through genetic drift and restored by natural selection.

Which of the following statements regarding fins on fishes is true? Fins are an adaptation that aid in swimming. Fins resulted from a mutation caused by a movement from land to water. Fins came about because animals couldn't live in water without them. Fins evolved so that fish could swim better.

Which of the following statements about adaptation is true? Adaptation is possible when all the alleles in a gene pool are the same. Adaptation results when cold temperatures cause mutations for longer fur. A population that has an increase in frequency of alleles for thicker fur has become adapted to the cold. An individual that has learned how to survive cold winters has become adapted to the cold.

Some butterflies can ingest toxic chemicals from the milkweed plants they feed on and then can store those chemicals in their body. Because toxins stored in the butterflies are toxic to birds, the birds avoid eating the butterflies. Which of the following is the best explanation for this situation? Any butterfly allele that allowed milkweed toxin storage would be likely to persist because butterflies that had it were more likely to survive. Milkweed plants wanted the butterflies to ingest the chemical so they would no longer feed on the plant, but the butterflies fooled the milkweed by storing the toxic chemicals. Butterflies developed a mutation that led them to be able to store the chemical because they needed to avoid being eaten. Butterflies that stored the chemicals were never eaten by predators, so those butterflies survived.

Which of the following disciplines has found evidence for evolution based on the native distributions (locations) of living species? geographic distribution paleontology comparative anatomy molecular biology

Which of the following statements regarding natural selection is false? Natural selection depends on the local environment at the current time. Natural selection and evolutionary change can occur in a short period of time (a few generations). Natural selection starts with the creation of new alleles that are directed toward improving an organism's fitness. Natural selection can be observed working in organisms alive today.

A population of butterflies has an allele B for big spots on the wings and b for small spots on the wings. The table below provides data about this population. Genotype BB Bb bb Number of butterflies 300 400 300 Genotype frequency 0.3 0.4 0.3 Regarding these data about the butterfly population, which of the following statements is correct? The population is in Hardy-Weinberg equilibrium because half of the heterozygotes are B and half are b. The population is in Hardy-Weinberg equilibrium because the number of B alleles is equal to the number of b alleles. The population is not in Hardy-Weinberg equilibrium because the genotype frequency of bb is greater than it would be in equilibrium. The population is not in Hardy-Weinberg equilibrium because p2 and 2pq are different.

A news article discussing the evolution of domestic dogs from wolves included this statement: "On its way from pack-hunting carnivore to fireside companion, dogs learned to love—or at least live on—wheat, rice, barley, corn, and potatoes." What is a more scientifically accurate way to state what happened with dogs? Being around humans represented an advantage, so wolves were able to take advantage of that by changing their digestion to be able to eat wheat, rice, barley, corn, and potatoes. Dogs mutated to be able to eat wheat, rice, barley, corn, and potatoes. Some wolves may have had variants in their digestion that allowed them to eat wheat, rice, barley, corn, and potatoes and so were able to survive with humans. Dogs were created at the same time as wolves.

Which of the following will tend to produce adaptive changes in populations? gene flow genetic drift natural selection the founder effect

Lyell's book Principles of Geology, which Darwin read on board the H.M.S. Beagle, argued in favor of which of the following concepts? Earth's surface is shaped mainly by occasional catastrophic events. Meteorite impacts may have been a major cause of periodic mass extinctions. The processes that shape Earth today are very different from those that were at work in the past. Earth's surface is shaped by natural forces that act gradually and are still acting.

Imagine that you are studying a very large population of moths that is isolated from gene flow. A single gene controls wing color. Half of the moths have white-spotted wings (genotype WW or Ww) and half of the moths have plain brown wings (ww). There are no new mutations, individuals mate randomly, and there is no natural selection on wing color. How will p, the frequency of the dominant allele, change over time? p will fluctuate rapidly and randomly because of genetic drift. p will neither increase nor decrease; it will remain more or less constant under the conditions described. p will increase; the dominant allele will eventually take over and become most common in the population. p will decrease because of genetic drift.

Brown-eye genes are dominant over blue-eye genes. What is the best explanation for the fact that all the blue-eye alleles have not disappeared in the human population? People with brown eyes tend to choose mates with brown eyes, and blue-eyed people tend to choose mates with blue eyes. Some blue alleles are always hidden in heterozygotes. The population is likely in Hardy-Weinberg equilibrium for that locus. Brown-eyed people sometimes have a blue-eyed parent.

A woman struggling with a bacterial illness is prescribed a month's supply of a potent antibiotic. She takes the antibiotic for about two weeks and feels much better. Should she save the remaining two-week supply, or should she continue taking the drug? She should save the drug for later, because if she keeps taking it the bacteria will evolve resistance. She should save the drug for use the next time the illness strikes. She should save the drug because antibiotics are in short supply and she may need it to defend herself against a bioterrorism incident. She should continue taking the drug until her immune system can completely eliminate the infection. Otherwise, some bacteria may remain in her system, and they will probably be resistant.

After a copper smelter begins operation, local downwind populations of plants begin to adapt to the resulting air pollution. Scientists document, for example, that the acid tolerance of several plant species has increased significantly in the polluted area. This is an example of directional selection. stabilizing selection. disruptive selection. genetic drift.

The core theme of biology, which explains both the unity and diversity of life, is genetics. ecology. metabolism. evolution.

The sickle-cell allele produces a serious blood disease in homozygotes. Why doesn't natural selection eliminate this allele from all human populations? Natural selection occurs very slowly, but elimination of the sickle-cell allele is expected to occur soon. Natural selection is a positive force, so it does not eliminate alleles. In populations where endemic malaria is present, heterozygotes have an important advantage: They are resistant to malaria and therefore are more likely to survive and produce offspring that carry the allele. Mutations keep bringing the allele back into circulation.

Which of the following terms represents the frequency of heterozygotes in a population that is in Hardy-Weinberg equilibrium? p q2 q 2pq

Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of coincidental similarity. homology. geographic similarity. adaptation by natural selection.

Which of the following statements would Darwin have disagreed with? Descent with modification occurs by natural selection. Living species have arisen from earlier life-forms. Species change over time. Descent with modification occurs through inheritance of acquired characteristics.

Which of the following conditions would tend to make the Hardy-Weinberg equation more accurate for predicting the genotype frequencies of future generations in a population of a sexually reproducing species? little gene flow with surrounding populations mutations that alter the gene pool a small population size a tendency on the part of females to mate with the healthiest males

The change in curves in the graph represents the appearance of a new allele for darker color in a population of mice. a decrease in genetic variation in a population of mice. a lack of genetic variation for light fur color in the original population of mice. a shift in the range of genetic variation in a population of mice.

Which of the following represents a pair of homologous structures? the antennae of an insect and the eyes of a bird the wing of a bat and the scales of a fish the wing of a bat and the wing of a butterfly the wing of a bat and the flipper of a whale

Which of the following statements best describes the true nature of natural selection? Heritable traits that promote reproduction become more frequent in a population from one generation to the next. The strong eliminate the weak in the race for survival. Organisms change by random chance. Only the strongest survive.

A population of 1,000 birds exists on a small Pacific island. Some of the birds are yellow, a characteristic determined by a recessive allele. The others are green, a characteristic determined by a dominant allele. A hurricane on the island kills most of the birds from this population. Only 10 remain, and those birds all have yellow feathers. Which of the following statements is true? The hurricane has caused a population bottleneck and a loss of genetic diversity. This situation illustrates the effect of a mutation event. The 10 remaining birds will mate only with each other, and this will contribute to gene flow in the population. Assuming that no new birds come to the island and no mutations occur, future generations of this population will contain both green and yellow birds.

A population is a group of individuals of different species living in the same place at the same time. a group of individuals of a species plus all of the other species with which they interact. all individuals of a species, regardless of location or time period in which they live. a group of individuals of the same species that live in the same area and interbreed.

A rabbit population consists of animals that are either very dark on top or very light on top. The color pattern is not related to sex. No rabbit shows intermediate coloration (medium darkness). This pattern might result from stabilizing selection. sexual selection. disruptive selection. directional selection.

The recessive allele of a gene causes cystic fibrosis. For this gene among Caucasians, p = 0.98. If a Caucasian population is in Hardy-Weinberg equilibrium with respect to this gene, what proportion of babies is born homozygous recessive and therefore suffers cystic fibrosis? 2(0.02 × 0.98) = 0.0392 (0.02)2 = 0.0004 0.02 (0.98)2 = 0.9604

Genetic differences between populations tend to be reduced by gene flow. the founder effect. natural selection. mutation.

Which statement best describes the mode of selection depicted in the figure? directional selection, favoring the average individual stabilizing selection, changing the average color of the population over time disruptive selection, favoring the average individual directional selection, changing the average color of the population over time

Darwin found that many of the species on the Galápagos islands were identical to South American species. resembled species from Australia. resembled species on the nearest mainland. resembled species in Europe.

Thirty people are selected for a long-term mission to colonize a planet many light-years away from Earth. The mission is successful, and the population rapidly grows to several hundred individuals. However, certain genetic diseases are unusually common in this group, and the group's gene pool is quite different from that of the Earth population they have left behind. Which of the following phenomena has left its mark on this population? bottleneck effect natural selection founder effect high rates of mutation

During the 1950s, a scientist named Lysenko tried to solve the food shortages in the Soviet Union by breeding wheat that could grow in Siberia. He theorized that if individual wheat plants were exposed to cold, they would develop additional cold tolerance and pass it to their offspring. Based on the ideas of artificial and natural selection, do you think this project worked as planned? No, because Lysenko took his wheat seeds straight to Siberia instead of exposing them incrementally to cold. Yes, because this is generally the method used by plant breeders to develop new crops. Yes; the wheat probably evolved better cold tolerance over time through inheritance of acquired characteristics. No, because there was no process of selection based on inherited traits. Lysenko assumed that exposure could induce a plant to develop additional cold tolerance and that this tolerance would be passed to the plant's offspring.

Genetic drift resulting from a disaster that drastically reduces population size is called