BIO Ch. 11-12 Quiz

- directional - disruptive - stabilizing

3 types of natural selection

87%

A population contains an equal number of large-beaked and small-beaked finches. If natural selection results in 85% of the birds with small beaks dying, what percentage of the population is now composed of large-beaked birds?

36

A population of 100 sea stars is in Hardy-Weinberg equilibrium. The trait for long arms is completely dominant to the trait for short arms. In this population, 40% of all alleles for this trait are recessive, and 60% of all alleles for this trait are dominant. How many individuals would you expect to be homozygous dominant for the arm length allele?

genetic drift - bottleneck effect

An earthquake causes the size of a deer population to drop rapidly over a short period. Allele frequencies shift. What mechanism of evolution does this situation illustrate?

Directional Selection

Ancestors of giraffes with shorter necks could not reach branches high up in trees for food. This led to _____ for giraffes with longer necks.

disruptive selection

Ancestors of the Galápagos finches had two different types of seeds to eat on some islands. Some seeds were very small and required small beaks to handle. Other seeds were very large and required large strong beaks to crack. This led to _____ among the Galápagos finches.

All answers correct

Antibiotic resistance is becoming more common in disease-causing bacteria because

descent with modification

Darwin referred to a gradual change from an ancestral type as

artificial selection

Farmers and horticulturalists bred broccoli, cauliflower, kale, and cabbage from the wild mustard plant through

- individuals with adaptations to their environment pass on their genes to more offspring - natural selection acts on genetic variation of organisms in a population

How does natural selection operate

0.3

In a population of 200 fish, 182 fish are blue, and 18 fish are red. 84 of the 182 blue fish are heterozygous for the color trait. What is the frequency of the red allele in the population? (Assume simple dominance/recessiveness of the color allele.)

0.6

In a population of 200 mice, 168 mice are black, and 32 mice are white. 96 of the black mice are heterozygous for the color trait. What is the frequency of the black allele in the population? (Assume simple dominance/recessiveness of a single gene with two alleles for the fur color trait.)

only 2 alleles exist for that gene

In the Hardy-Weinberg equation, p + q = 1, p and q represent the frequency of alleles in a population of diploid organisms if

Heterozygous Individuals

In the Hardy-Weinberg equation, p2 + 2pq + q2 = 1, 2pq represents the frequency of

Genetic Variation

Natural selection requires genetic variation, competition for limited resources, overproduction of offspring, and unequal reproductive success. The subset of finches that is capable of eating large seeds, while many others eat small seeds, is an example of which requirement?

- Malthus's ideas on limited resources - Wallace's natural selection

Select the answers that correctly pair the person with his idea, AND that support Darwin's hypotheses about the diversity of life. (Select all that apply.)

1. One nucleotide is substituted for another in finch DNA 2. Mutated DNA is transcribed 3. Introns removed from mutated mRNA 4. mRNA leaves the nucleus 5. mRNA translated to protein

Starting with a DNA mutation, arrange the events to explain how the new beak shape became common in the population.

bottleneck effect

The North American bison was hunted to near-extinction in the 1800s. It has since recovered, but with decreased genetic diversity. This is an example of

Small groups of individuals leave their home population and establish new settlements, mating only among themselves

The founder effect occurs when

Charles Lyell

The geologist who suggested that natural processes are slow and steady and that the Earth is much older than 6,000 years was

Stabilizing Selection

The mode of natural selection in which extreme phenotypes are less fit than the optimal intermediate phenotype is

32%

Use the Hardy-Weinberg equations: p + q = 1 and p2 + 2pq + q2 = 1. If the dominant allele frequency is 0.8, what percentage of the population will be heterozygous?

bottleneck effect

Which type of genetic drift occurs when many members of a population die, resulting in a great loss of genetic diversity?

over generations

evolution occurs

gene pool

the entire collection of genes and alleles is a populations