Exam 4 - Genes and The Evolution of Populations

The frequency of two alleles in a gene pool is 0.19 (A) and 0.81(a). Calculate the percentage of heterozygous individuals in the population. Calculate the percentage of homozygous recessives in the population. Assume that the population is in Hardy-Weinberg equilibrium.

31%, 66%

Within a population of butterflies, the color brown (B) is dominant over the color white (b). And, 40% of all butterflies are white. Given this simple information, which is something that is very likely to be on an exam, calculate the following: The percentage of butterflies in the population that is heterozygous? The frequency of homozygous dominant individuals?

47% , .137

In a population that is in Hardy-Weinberg equilibrium, the frequency of the recessive homozygote genotype of a certain trait is 0.09. Calculate the percentage of individuals homozygous for the dominant allele.

49%

In corn, kernel color is governed by a dominant allele for white color (W) and by a recessive allele (w). A random sample of 100 kernels from a population that is in H-W equilibrium reveals that 9 kernels are yellow (ww) and 91 kernels are white. Calculate the frequency of yellow alleles? A. 0.30 B. 0.03 C. 0.5 D. 0.7

A. 0.30

A sudden major climatic change would most likely initially result in: A. A rapid increase in adaptive radiation B. A rapid increase in extinction rates C. A sharp increase in numbers of species D. An increase in mutation rates E. Plants and animals developing new characteristics in order to cope with environmental changes

B. A rapid increase in extinction rates

14. The wing structures of bats and birds are examples of which of the following? A. Speciation B. Convergent evolution C. Divergent evolution D. Homology

B. Convergent evolution

Which of the following best represents Lamarck's ideas on the evolutionary process? A..Survival of the fittest B. Inheritance of acquired characteristics C. Neutral drift D. Punctuated equilibrium E. Assortative mating

B. Inheritance of acquired characteristics

The ability to taste phenylthiocarbamide (PTC) is a trait controlled by 2 alleles (PTC taster and PTC non-taster). Suppose 36% of a remote mountain village cannot taste PTC and must, therefore, be homozygous recessive (aa) for the PTC non-taster allele. If this population conforms to Hardy-Weinberg expectations for this gene, what percentage of the population must be homozygous (AA) for the PTC taster allele? A) 48% B) 40% C) 16% D) 32% E) 60%

C) 16%

A rare disease which is due to a recessive allele (a) that is lethal when homozygous (aa), occurs with a frequency of one in a million. How many individuals in a town of 14,000 can be expected to carry this allele? A. 30 B. 15 C. 28 D. 40

C. 28

The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid-1700s. They do not marry with members outside their own immediate community. Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci, from all other populations including their original homeland. Which of the following likely explains the genetic uniqueness of this population? A) sexual selection and inbreeding depression B) heterozygote advantage and stabilizing selection C) population bottleneck and Hardy-Weinberg equilibrium D) mutation and natural selection E) founder effect and genetic drift

E) founder effect and genetic drift

The evolutionary theory proposed by Charles Darwin was: A. Change in populations through time as a result of mutations B. The spontaneous generation of new organisms C. The passing on of genes from one generation to the next D. Change in populations through time as a response to environmental change E. The development of characteristics by organisms in response to need

E. The development of characteristics by organisms in response to need

In corn, kernel color is governed by a dominant allele for white color (W) and by a recessive allele (w). A random sample of 100 kernels from a population that is in H-W equilibrium reveals that 9 kernels are yellow (ww) and 91 kernels are white. Calculate the frequencies of the yellow and white alleles in this population. Calculate the percentage of this population that is heterozygous.

P = .7, q = .3, 42%

The ability to taste PTC is due to a single dominate allele "T". You sampled 215 individuals in biology, and determined that 150 could detect the bitter taste of PTC and 65 could not. Calculate allelic and genotypic frequencies for this population.

P = 45, q = 55, p^2 = .20, 2pq = .495, q^2 = .30

A population of sheep is in Hardy-Weinberg equilibrium. The allele for white wool (W) has an allele frequency of 0.19, and the allele for black wool (w) has an allele frequency of 0.81. a. 31% b. 4% c. 66% d. 15%

a. 31%

An allele W, for white wool, is dominant over allele w, for black wool. In a sample of 900 sheep, 891 are white and 9 are black. Calculate the allele frequencies within this population, assuming that the population is in H-W equilibrium. a. Recessive allele frequency is 10% and the dominant allele frequency is 90% b. Recessive allele frequency is 20% and the dominant allele frequency is 60% c. Recessive allele frequency is 90% and the dominant allele frequency is 10% d. Recessive allele frequency is 25% and the dominant allele frequency is 75%

a. Recessive allele frequency is 10% and the dominant allele frequency is 90%

In a population that is in Hardy-Weinberg equilibrium, 38 % of the individuals are recessive homozygotes for a certain trait. In a population of 14,500, calculate the percentage of homozygous dominant individuals. a. 1000 b. 2133 c. 3456 d. 567

b. 2133

500 frogs are in a pond. In these frogs, yellow skin spots are a dominant trait. There are 350 frogs with yellow skin spots. How many frogs are probably Aa? a. 150 b. 248 c. 350 d. 252

b. 248

Allele T, for the ability to taste a particular chemical, is dominant over allele t, for the inability to taste the chemical. Four hundred university students were surveyed and 64 were found to be nontasters. Calculate the percentage of heterozygous students. Assume that the population is in H-W equilibrium. a. 22% b. 48% c. 44% d. 35%

b. 48%

Gene flow involves a. Natural disasters killing most of the members of a population b. Individuals moving into and out of the population c. Selective mating d. Small changes because of the environment

b. Individuals moving into and out of the population

If a population experiences no migration, is very large, has no mutations, has random mating, and there is no selection, which of the following would you predict? a. The population will evolve, but much more slowly than normal. b. The makeup of the population's gene pool will remain virtually the same as long as these conditions hold. c. The composition of the population's gene pool will change slowly in a predictable manner. d. Dominant alleles in the population's gene pool will slowly increase in frequency while recessive alleles will decrease. e. The population probably has an equal frequency of A and a alleles.

b. The makeup of the population's gene pool will remain virtually the same as long as these conditions hold.

If the frequency of two alleles in a gene pool is 90% A and 10% a, what is the frequency of individuals in the population with the genotype Aa? a. 0.81 b. .09 c. .18 d. .01 e. .198

c. .18

Within a population of 500 butterflies, the color purple is dominant over the color white. 200 of the butterflies are white. What is the frequency of homozygous dominant individuals? Give your answer as a decimal to the nearest hundredth. a. 0.40 b. 0.36 c. 0.16 d. 0.60

c. 0.16

The frequency of two alleles in a gene pool is 0.19 (A) and 0.81(a). Assume that the population is in Hardy-Weinberg equilibrium.Calculate the percentage of heterozygous individuals in the population. a. 50% b. 32% c. 31% d. 44%

c. 31%

A certain island-nation with a population of 200,000 has laws which severely restrict travel onto or off the island. There is an absolute prohibition against marrying foreigners, but island natives may marry as they wish. A non-lethal recessive genetic condition affects 2,000 of the people. How many carriers of this condition live on the island? a. 198,000 b. 96,000 c. 36,000 d. 12,400 e. 9,600

c. 36,000

In the Hardy-Weinberg equation, 2pq represents: a. The frequency of homozygous recessive individuals in the population. b. The frequency of homozygous dominant individuals in the population. c. The frequency of heterozygous individuals in the population. d. The number of hamsters it takes to screw in a lightbulb.

c. The frequency of heterozygous individuals in the population.

In humans, Rh-positive individuals have the Rh antigen on their red blood cells, while Rh-negative individuals do not. If the Rh-positive phenotype is produced by a dominant gene (A), and the Rh-negative phenotype is due to its recessive allele (a), what is the frequency of the Rh-positive allele if 84% of a population is Rh-positive? a 0.04 b 0.16 c 0.48 d 0.60 e 0.84

d 0.60

In a population of hamsters, 10 individuals are homozygous dominant, 5 are heterozygous, and 15 are homozygous recessive. What is p? a. 0.58 b. 0.3 c. 0.7 d. 0.42

d. 0.42

In a population that is in Hardy-Weinberg equilibrium, the frequency of the homozygous recessive genotype is 0.09. What is the frequency of individuals that are homozygous for the dominant allele? a. 0.7 b. 0.21 c. 0.42 d. 0.49 e. .91

d. 0.49

Which of the following is NOT a condition that must be met for Hardy-Weinberg equilibrium? a. Large population size b. No mutations c. No immigration or emigration d. Dominant alleles more frequent than recessive alleles e. No natural selection

d. Dominant alleles more frequent than recessive alleles

An allele W, for white wool, is dominant over allele w, for black wool. In a sample of 900 sheep, 891 are white and 9 are black. Calculate the allelic frequencies within this population, assuming that the population is in H-W equilibrium

p = .9, q = .1

The next generation of rabbits has 560 individuals with short ears and 840 individuals with floppy ears. Solve for p and q.

p = 0.23, q= 0.77

Rabbit's ears can be either short or floppy, where short ears are dominant over floppy ears. There are 653 individuals in a population. 104 rabbits have floppy ears and 549 have short ears. Find: the frequency of the dominant and recessive alleles and the frequency of individuals with dominant, heterozygous, and recessive genotypes.

p = 0.6, q = 0.4, p^2 = 0.36, 2pq = 0.48, q^2 = 0.16

The next generation of lizards has 1092 individuals with green scales and 108 individuals with blue scales. Solve for p and q.

p = 0.7, q = 0.3

Scale coloration of lizards has a complete dominance relationship where green scales are dominant over blue scales. There are 1,024 individuals with the genotype GG, 512 individuals with the genotype Gg, and 64 individuals with the genotype gg. Find: the frequency of the dominant and recessive alleles and the frequency of individuals with dominant, heterozygous, and recessive genotype.

p = 0.8, q = 0.2, p^2 = 0.64, 2pq = 0.32, q^2 = 0.04

The next generation of pea plants has 552 plants, 546 have purple petals. Solve for p and q.

p = 0.9, q = 0.1

Petal coloration of pea plants has a complete dominance relationship where purple petals are dominant over white petals. There are 276 plants, 273 have purple petals.Find: the frequency of the dominant and recessive alleles and the frequency of individuals with the dominant, heterozygous, and recessive genotype.

p = 0.9, q = 0.1, p^2 = 0.81, 2pq = 0.18, q^2 = 0.01

The beak color of finches has a complete dominance relationship where black beaks are dominant over yellow beaks. There are 210 individuals with the genotype DD, 245 individuals with the genotype Dd and 45 individuals with the genotype dd. Find: the frequency of the dominant and recessive alleles.

q= .3, p=.7

A population of cats can be either black or white; the black allele (B) has complete dominance over the white allele (b). Given a population of 1,000 cats, 840 black and 160 white, determine the allele frequency, the frequency of individuals per genotype, and number of individuals per genotype.

q^2=.16, q=.4, p=.6, p^2=.36, 2pq=.48