Bio 152 exam 1

In the c. coli long-term evolution experiment, the mutation allowing the e. coli to metabolize citrate occurred because the e. coli were growing on citrate. That is, if the e. coli were growing in some other condition, the mutation would not have happened. True or False?

In the c. coli long-term evolution experiment, the mutation allowing the e. coli to metabolize citrate occurred because the e. coli were growing on citrate. That is, if the e. coli were growing in some other condition, the mutation would not have happened. True or False?

False

Why did it take so many generations for the e. coli to be able to grow on citrate?

Select one:

a. because e. coli grows much more slowly on citrate.

b. It needed to use up the glucose first

c. because mutations are random and just need to happen.

d. because citrate is a very complicated molecule.

C

Which of the following is necessary for evolution by natural selection?

Select one or more:

a. Variation in heritable traits in the population

b. Differences in lifetime reproductive success based on traits

c. there must be sexual reproduction

d. some dramatic change in the environment.

a,b

Teosinte is a grass that grows wild in central America and includes several different very similar species. Over the course of thousands of years, the farmers of central American carefully culled undesirable offspring and cross bred various teosinte species ultimately developing Zea mays or what we usually call corn. Which of the following statements is true regarding this process?

Select one:

a. This is not an example of evolution because humans did the selection process.

b. It would be possible to carefully select modern corn plants to ultimately wind up with teosinte.

c. The artificial selection applied by humans caused mutations in teosinte leading to the development of corn.

d. This is an example of evolution through artificial selection.

d

The raw material for evolution is created by __________ mutations. Natural selection is a _________ process that acts upon the subsequent phenotypes to result in evolution.

random, nonrandom

What was Darwin's main contribution

Select one:

a. He was proposed evolution as the means of natural selection.

b. He proposed that artificial and natural selection differed only in that artificial selection couldn't lead to a new species.

c. He proposed that natural selection was the mechanism of evolutionary change.

d. He was the first to describe artificial selection.

e. He invented evolution.

c

Distinguish natural selection from artificial selection

Select one:

a. Artificial selection cannot lead to evolutionary change

b. Natural selection primarily selects organism that will live longer.

c. In artificial selection human breeders decide which organisms have offspring whereas in natural selection nature does this.

d. Artificial selection cannot create dramatic phenotypic changes.

c

The article argues that Darwin based his proposal for evolution by natural selection on four premises. If you released a group of genetically identical pigs into the wilds of western massachusetts to fend for themselves they might slowly adapt to their environment (over many generations), but the population would not conform to one of the premises. Which one?

Select one:

a. Organisms are variable.

b. At least some of the organisms' variability is heritable.

c. More offspring are produced than required for parental replacement.

d. Most organisms have stable populations.

a

Select the statement that is correct regarding the studies of the galapagos finches as presented in this article.

Select one:

a. The finches that hatched in 1978 after the severe drought in 1977 grew smaller beaks in order to make it possible to eat the smaller seeds.

b. The changes in the bill size in Galapagos finches is an example of artificial selection not natural selection because the Grants identified the birds who could breed.

c. Bill dimensions must be a heritable trait (parents with larger bills will have offspring with larger bills).

d. All of the data concerning the Galapagos finches are dependent on the weather changes caused by climate change.

e. The changes in bill dimensions observed in the Galapagos finches shows the natural selection acts on the population as a whole not on individuals.

c

In terms of evolution by natural selection, why does an individual's survival matter?

Select one:

a. Because survival of the fittest is what matters in terms of evolution.

b. Surviving longer demonstrates that an individual is stronger and therefore "more fit."

c. Surviving longer means that the individual is better able to deal with the abiotic and biotic challenges of its environment.

d. Surviving longer means that more opportunities to reproduce and therefore contribute more copies of that individual's genes to subsequent generations.

e. Survival does not matter at all.

d

All the alleles present in all individuals in a species are referred to as the ____________ of that species.

Select one:

a. gene pool

b. allele frequency

c. genotype frequency

d. genotype

e. phenotype

a

In a population of butterflies has the following gene frequencies: 60% AA, 20% Aa, and 20% aa. What is the frequency of the A allele?

Select one:

a. 0.6

b. 0.8

c. 0.7

d. 0.2

e. 0.3

c

proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do not seem to be optimally arranged because

Select one:

a. natural selection has not had sufficient time to create the optimal design in each case, but will do so given enough time.

b. in many cases, phenotype is not merely determined by genotype, but by the environment as well.

c. though we may not consider the fit between the current skeletal arrangements and their functions excellent, we should not doubt that natural selection ultimately produces the best design.

d. natural selection is generally limited to modifying structures that were present in previous generations and in previous species.

d

Which of the following is a true with respect to genetic variation?

Select one:

a. Genetic variation is created by natural selection.

b. It arises in response to environmental change.

c. It must be present in a population before natural selection can act upon the population.

d. It tends to be reduced by meiosis.

c

From an evolutionary perspective, germ-line mutations are more significant than somatic mutations. This is because:

Select one:

a. somatic mutations affect only one or a few cells.

b. somatic mutations are generally harmful.

c. only germ-line mutations will appear in an individual's descendants.

d. only germ-line mutations are potentially beneficial to the individual

e. somatic mutations affect only one or a few cells and only germ-line mutations will appear in an individual's descendants.

c

Which of the following big sagebrush plants is the most fit, based only on the information in the answers?

Select one:

a. The individual that can survive with 10% less water than the others in its population.

b. The individual that produces 5% more distasteful chemicals, making it 2% less likely to be attacked by herbivores than others in its population.

c. The individual that produces 3% more offspring each year than others in its population.

d. The individual that is the most resistant to disease organisms in the population.

e. All of these individuals are equally fit based on the information presented.

c

There are three alleles are a specific locus in a population of humans. The alleles are D1, D2, and D3 and they have frequencies of 0.43, 0.30, and 0.28 respectively.

Select one:

a. D1 is dominant

b. D1 is definitely not dominant

c. It cannot be determined from this information whether D1 is dominant

c

A population of naked mole rats has a recessive allele that in the homozygous state leads to a distinct splotchy skin phenotype. The un-mutated allele is denoted A whereas the splotchy allele is a. Naked mole rats are blind as well as naked and show no preference or distaste for the splotchy allele. There are no other evolutionary pressures and so it is in Hardy Weinberg equilibrium at this locus. The frequency of the a allele is 0.2. What is the percentage of the population that is heterozygous at this locus (Aa)?

Select one:

a. 0.2

b. 2.0

c. 4.0

d. 16.0

e. 32.0

e

What are the assumptions that must be true for Hardy Weinberg equilibrium to exist at a particular gene locus?

Select one or more:

a. P2 + 2pq + q2 =1

b. Natural selection is not acting on this particular gene locus.

c. Neither mutation nor migration is introducing new alleles at this particular locus

d. Population size is infinite.

e. Random mating

b,c,d,e

What does it mean that Hardy Weinberg equilibrium is a "neutral equilibrium"

Select one:

a. It means that if you add up all the genotype frequencies they will equal 1 (i.e. p2 + 2pq + q2 =1

b. It means that if the allele frequencies change for some reason in one generation they will come back to the SAME allele frequency in the next generation.

c. It means that if the allele frequencies change for some reason in one generation they will reach a NEW equilibrium level after just one generation of random mating

d. It means that allele frequencies can vary a bit as long as p+q=1

e. It means that allele frequencies can vary but genotype frequencies cannot.

c

As with Hardy Weinberg equilibrium, genetic drift is a bigger problem in large populations.

Select one:

True

False

False

How can genetic drift lead to fixation of an allele (let's say there are two alleles Q and q, how can genetic drift lead to fixation of q).

Select one:

a. The dominant allele is more likely to go to fixation.

b. If one allele (e.g. q) is randomly lost from the population, which can happen easily in a small population, then genetic drift has lead to fixation of the other allele (in this case Q)

c. If a small population with one of the alleles (q) mixes with another population that has the other allele (Q) this can lead to fixation.

d. If one of the alleles (Q) leads to reproductive advantage, it could quickly go to fixation.

b

Genetic drift refers to a ________ event that _______ lead to the evolution of a species.

random, can

You are maintaining a small population of fruit flies in the laboratory by transferring a quarter of the the offspring flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flies has decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to

Select one:

a. Ask your friend who also works on flies to give you some fresh wild type flies from the population she maintains in another lab.

b. reduce the number of lies that you transfer at each generation

c. transfer only the largest flies every generation

d. change the temperature at which you rear the flies

e. shock the flies with a brief treatment of heat or cold to make them more hardy

a

A hypothetical endangered species of wildflower has been reduced to a single small population in a mountain meadow. A group takes over the meadow in an act of anti-government defiance. They trample all but three of the flowers. This could result in what for the gene pool of this wildflower?

Select one:

a. natural selection

b. genetic drift

c. mutation

d. migration

e. non-random mating

b

Flower color in sweet pea in part comes from the pigment anthocyanin. One step is catalyzed by an enzyme called chalcone synthase. When chalcone synthase doesn't work at all , the flowers are white. The normal enzyme is denoted + whereas the non-functioning enzyme is denoted -. Heterozygotes are purple. In a particular large population the following genotype frequencies are observed:

genotype frequencies

Genotype Frequency

++ 0.60

+- 0.20

-- 0.20

What is the frequency of the - allele in this population?

0.30

Flower color in sweet pea in part comes from the pigment anthocyanin. One step is catalyzed by an enzyme called chalcone synthase. When chalcone synthase doesn't work at all , the flowers are white. The normal enzyme is denoted + whereas the non-functioning enzyme is denoted -. Heterozygotes are purple. In a particular large population the following genotype frequencies are observed:

genotype frequencies

Genotype Frequency

++ 0.60

+- 0.20

-- 0.20

What is the expected heterozygote frequency that would suggest the population is in hardy weinberg equilibrium?

0.42

Flower color in sweet pea in part comes from the pigment anthocyanin. One step in anthocyanin production is catalyzed by an enzyme called chalcone synthase. When chalcone synthase doesn't work at all , the flowers are white. The normal enzyme is denoted "+" whereas the non-functioning enzyme is denoted "-." Heterozygotes are purple. In a particular large population the following genotype frequencies are observed:

genotype frequencies

Genotype Frequency

++ 0.60

+- 0.20

-- 0.20

Is this population in hardy Weinberg equilibrium? Please note that you should use your answers to the last two questions to help you answer this question?

Select one:

a. yes

b. no

c. there is not enough information provided to answer this question

b

In humans, hair straightness or curliness is thought to be governed by a single pair of alleles showing partial dominance. Individuals with straight hair are homozygous for the S allele, while those with curly hair are homozygous for the c allele. Individuals with wavy hair are heterozygous (Sc). In a population 25% were found to have straight hair, 40% had curly hair, and 35% had wavy hair. Is this population in hardy Weinberg equilibrium?

Select one:

a. No, there are too few heterozygotes in the observed group

b. No, there are too many heterozygotes in the observed population

c. Yes

d. It is impossible to determine from the data given.

a

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

Select one:

a. geographic isolation

b. niche differences

c. gene flow (the ability to exchange alleles and genes during reproduction)

d. morphological similarity

e. molecular (DNA, RNA, protein) similarity

c

A drawback of the BSC is that it cannot be applied to

Select one or more:

a. polymorphic species (like ants)

b. asexual organisms like bacteria

c. extinct organisms like dinosaurs

d. plants

e. none of these are drawbacks

b,c

Dogs (Canis lupus familiaris) and gray wolves (Canis lupus) can interbreed to produce viable, fertile offspring. These species shared a common ancestor recently (in geologic time) and have a high degree of genetic similarity, although their anatomies vary widely. Judging from this evidence, which two species concepts are most likely to place dogs and wolves together into a single species?

Select one:

a. ecological and morphological

b. ecological and phylogenetic

c. morphological and phylogenetic

d. biological and morphological

e. biological and phylogenetic

e

You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?

Select one:

a. biological

b. evolutionary

c. ecological

d. morphological

d

Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet?

Select one:

a. They interbreed freely and produce fertile hybrid offspring.

b. They no longer attempt to interbreed.

c. They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations.

d. They remain separate in the extremes of their ranges but develop a persistent hybrid zone in the area of overlap.

e. They interbreed in the region of overlap, but produce sterile offspring.

c

It is thought that polar bears originated from a population of brown bears (grizzlies) that became geographically isolated during a glaciation event that occurred about 150,000 years ago. This is an example of:

Select one:

a. sympatric speciation

b. allopatric speciation

c. peripatric speciation

d. adaptive radiation

b

occurs when a species separates into two separate groups which are isolated from one another. A physical barrier, such as a mountain range or a waterway, makes it impossible for them to breed with one another. Each species develops differently based on the demands of their unique habitat or the genetic characteristics of the group that are passed on to offspring.

allopatric speciation

When small groups of individuals break off from the larger group and form a new species

peripatric speciation

a species is spread out over a large geographic area. Although it is possible for any member of the species to mate with another member, individuals only mate with those in their own geographic region.

parapatric speciation

occurs when there are no physical barriers preventing any members of a species from mating with another, and all members are in close proximity to one another.

sympatric speciation