genetics replacement exam

6

In diploid cells of mosquitos, there are a total of six chromosomes. How many chromatids are present in a mosquito secondary oocyte?

48

6

24

3

12

2

The recessive trait "does not like LSU football" is thought to be controlled by several genes showing Mendelian inheritance and simple dominance/recessiveness. Crosses are conducted among a group of LSU students who do not like LSU football, with the following results:

student 1 x student 2---> F1 like football

student 1 x student 3---> F1 do not like football

student 1 x student 4---> F1 like football

student 2 x student 3---> F1 like football

student 2 x student 4---> F1 do not like football

student 3 x student 4---> F1 like football

How many different genes are involved in the trait "does not like LSU football" based on these results?

2

4

3

1

1/32

This question concerns three independently assorting genes in dogs. Red coat (r) is recessive to black coat (R), spotted coat (s) is recessive to solid coat (S), and curly tail (c) is recessive to straight tail (C). From the cross Rr Ss Cc X Rr ss Cc, what fraction of the puppies will have a red solid coat and a curly tail?

1/4

1/16

1/8

1/32

0

ey+ey cn+cn x ey+ey cn cn

The recessive eyeless mutation results in flies with no eyes, in contrast to wild-type flies that have eyes. The recessive cinnabar mutation results in flies with bright red "cinnabar" eyes, in contrast to the wild type dull red eye color. A fly with wild-type eyes was mated to a fly with cinnabar eyes, and the following offspring were obtained:

52 eyeless, 72 wild-type eyes, 76 cinnabar eyes

What were the genotypes involved in the cross?

* ey+ey cncn x ey+ey cncn

* ey+ey cn+cn x ey+ey cn cn

* ey+ey cn+cn+ x ey+ey cncn

* ey+ey cn+cn x ey+ey cn+ cn

c

In a certain plant, two traits have been observed that show simple Mendelian inheritance, tall vs. short plant height (tall is dominant to short), and white vs. blue seeds (white is dominant to blue). Two tall plants with white seeds that are both heterozygous for both of the genes are crossed, and among 500 total offpring the following results are obtained:

White seed, tall plant 270

White seed, short plant 100

Blue seed, tall plant 97

Blue seed, short plant 33

Based on a chi squared test, are these results consistent with the hypothesis that these two genes assort independently? Use the Chi squared table in your book.

A * Results consistent with hypothesis, chi squared = 247.2

B * Results not consistent with hypothesis, chi squared = 436

C * Results consistent with hypothesis, chi squared = 1.08

D * Results not consistent with hypothesis, chi squared = 247.2

E * Results not consistent with hypothesis, chi squared = 1.08

0.9

On a beach in near Pensicola, Florida, 100 mice with dark coats produced 135 offspring, while 100 mice with white coats produced 150 offspring. What was the relative fitness of the mice with dark coats?

0.95

1.35

0.8

0.9

1.0

d

A haplotype is:

A * A type of rare "private" allele that is limited to a single population

B * A general term for gametes

C * A type of chromosome abnormality caused by nondisjunction

D * A group of alleles near each other on a chromosome that tend to remain together due to linkage

E * A term referring to the fact that males only have one X chromosome

0.0375

A series of flower color pigments in a certain plant are produced by the following biochemical pathway:

white -------> yellow -----> pink ------> red

Gene A encodes the enzyme that converts white to yellow, gene B encodes the enzyme that converts yellow to pink, and gene C encodes the enzyme that converts pink to red. The recessive allele of each gene encodes a non-functional amorphic enzyme. Genes A and C are 15 cM apart on the same chromosome. Gene B is located on a different chromosome and assorts independently.

From the test cross Ac/aC Bb x ac/ac bb , what fraction of the offspring will have red flowers?

(Note that the first parent is heterozygous for all three genes, but A and C are in repulsion!)

* 0.075

* 0.125

* 0.25

* 0.0375

* 0.0188

0.19

The ability to taste the bitter compound PTC is due to a dominant allele, T. Homozygous tt individuals cannot taste PTC. In a sample of 500 people, 320 could taste PTC and 180 could not. Filled symbols in the pedigree below are non-tasters (tt). If the woman at the far right in generation III of the pedigree, who is a taster, marries a man who also can taste PTC and is from the population described, what is the chance that a child born to them will NOT be able to taste PTC?

1 B (w) x G (w)

11 b (w) & b (b) & b (w)-g (b)

iii g (b) & g (w) & g (w)

0.19

0.25

0.15

0.09

0.12

Female Drosophila with cinnabar eye (cn) and vestigial wings (vg) were mated to males with roof wings (rf). The F1 were all wild-type. When the F1 females were test crossed withmales homozygous for all three traits the following offspring were obtained:

382 cinnabar, vestigial

401 roof

3 cinnabar

4 roof, vestigial

59 cinnabar, roof, vestigial

67 wild-type for all traits

44 cinnabar, roof

40 vestigial

The 67 flies that have the wild-type phenotype for all traits are the result of a single cross-over that occurred between which two genes?

A * This class is a double-crossover class

B * Between vg and rf

C * Between rf and cn

D * Between vg and cn

D

Neanderthals were an extinct species closely related to modern humans. In 2015, an ~40,000 year old human skeleton was found in Romania. Genome sequencing revealed that about 6% of the genome of this individual had come from a Neanderthal ancestor. This individual appears to have had a Neanderthal ________.

A) parent

B) grandparent

C) great grandparent

D) gg grandparent

e) ggg grandparent

s

The DNA of a cell is replicated during what phase of the mitotic cell cycle?

A) g1

B) S

C) g2

D) M

E) cytokinesis

B

The genome of the fruit fly Drosophila melanogaster contains 1.4 x 108 bp of DNA, and approximately 20% of the genome codes for proteins. If the average protein encoded by each Drosophila melanogaster gene contains 580 amino acids, approximately how many protein coding genes are present in the Drosophila melanogaster genome?

A) 6,000

B) 16,000

C) 24,000

D) 80,000

E) 240,000

B

Which of the following people was the first to choose the fruit fly Drosophila melanogaster as a research organism for genetics?

A) Calvin Bridges

B) T.H. Morgan

C) Janet Rowland

D) Mary Lyon

E) Huge De Vries

D

Which of the following people proposed the X chromosome inactivation hypothesis?

A) Calvin Bridges

B) T.H. Morgan

C) Janet Rowland

D) Mary Lyon

E) Huge De Vries

A

Stephen Pinker's genotype predicts that he should be bald, yet he has a full head of hair. This is an example of:

A) Incomplete penetrance

B) incomplete dominance

C) codominance

D) epistasis

E) hypomorph

C

The next four questions refer to the following cross involving the independently assorting genes A, B, C, D, E, and F. Unless otherwise stated, assume that the capitalized allele is fully dominant, and that these genes show no genetic interactions (epistasis, etc.)

Aa bb cc Dd Ee x aa Bb Cc dd Ee

How many different types of gametes can the parent on the right produce?

A) 2

B) 4

C) 8

D) 16

E) 32

B

From the cross of independently assorting genes showing simple dominance, Aa bb cc Dd Ee x aa Bb Cc dd Ee

how many different types of phenotypes can be produced?

A) 24

B) 32

C) 48

D) 216

E) 243

B

From the cross of independently assorting genes Aa bb cc Dd Ee x aa Bb Cc dd Ee

what proportion of A_ B_ C_ D_ E_ individuals will be produced?

A) 1/64

B) 3/64

C) 9/64

D) 1/128

E) 0

E

From the cross of independently assorting genes Aa bb cc Dd Ee x aa Bb Cc dd Ee

what proportion of AA Bb cc Dd ee individuals will be produced?

A) 1/64

B) 3/64

C) 9/64

D) 1/128

E) 0

c

A researcher has two strains of mosquito, one with golden eyes and normal wings, and one with normal eyes and bent wings. Both strains are true-breeding. She crosses these two strains to get an F1, which has both normal eyes and normal wings. When the F1 are crossed with each other, in the resulting F2 she finds the following progeny:

472 normal eyes and wings

138 golden eyes and normal wings

145 normal eyes and bent wings

45 golden eyes and bent wings

Do these results fit the expectation for two independently assorting genes controlling these two traits (see Chi2 table below)?

A) . Chi2= 1.08, results consistent with two independently assorting genes.

B) Chi2= 1.08, results not consistent with two independently assorting genes

C) Chi2= 2.7, results consistent with two independently assorting genes

D) Chi2= 2.7, results not consistent with two independently assorting genes.

E) Chi2>>100, results not consistent with two independently assorting genes.

in cats, the wild-type allele (C) of the gene coding for the enzyme tyrosinase results in uniformly dark black fur. Siamese cats have pale fur with dark brown "points" on the tips of the ears, the nose, and the paws due to the cs allele, which is fully recessive to C. Burmese cats have chocolate brown fur, caused by the cb allele, which is also recessive to C. Heterozygous cs cb heterozygous cats show incomplete dominance, and have light chocolate fur with dark brown points.

In a litter of kittens, half of the offspring are black, and half have light chocolate fur with dark brown points. What are the genotypes of the parents?

A) Cc^b x Cc^s

B) Cc^b x c^sc^s

C) Cc^s x c^bc^b

D) either a or b

E) either b or c

B

ABO blood type is controlled by gene I, with three alleles, IA, IB and IO. MN blood type is controlled by the independently assorting gene L, with two codominant alleles, LM and LN.

In the showGame of Thrones, the character Jon Snow is believed to be the child of Rhaegar Targaryen (blood type AB, N) and Lyanna Stark (bloodtype A, M). If true, he has a very strong claim to the Iron Throne. Which of the following blood types is the only one that is consistent with Jon Snow being the son of Rhaegar Targaryen and Lyanna Stark?

A) AB, M

B) A, MN

C) B, N

D) O, MN

E) O, N

B

A Drosophila fruit fly whose sex chromosome genotype was XXY would develop as a:

A) male

B) female

D

The I gene involved in ABO blood type encodes an enzyme that modifies the polysaccharide chains found on cellular glycoproteins. In a sperm cell of a man of blood type BB, a mutation occurs causing an amorphic allele of the I gene. This sperm cell carrying the mutant allele fertilizes one of his wife's eggs. His wife's blood type is O. What is the child's blood type?

A) AB

B) A

C) B

D) O

D

A mutation occurs in an enzyme that detoxifies environmental poisons in mosquitos. This mutation allows the mosquito to detoxify an insecticide that most mosquitoes cannot detoxify, causing mosquitoes carrying this mutation to be resistant to the insecticide. This mutation is a/an:

A) amorph

B) hypomorph

C) hypermorph

D) neomorph

E) nondisjunction

D

Factor V Leiden is an autosomal dominant disease that causes blood to clot more readily, resulting in increased risk of venous thrombosis (blood clots forming in veins)? A woman with increased blood clotting has a paternal grandfather with increased clotting due to Factor V Leiden, but her father had normal clotting. What is the most likely explanation for why her father does not show the phenotype?

A) sex linkage

B) codominance

C) incomplete dominance

D) incomplete pentrance

E) nondisjunction

B

Most salamanders of a certain species are black with red spots. A researcher discovers salamanders of this species from three widely separated locations that are solid red. All three red varieties are recessive when crossed to common black with red spots salamanders. To test how many genes are involved in causing this phenotype among the three red varieties, all possible crosses were performed among the three red varieties. The results are as follows:

Cross # Genotypes crossed F1 phenotype

1. a x b black with red spots

2. a x c solid red

3. b x c black with red spots

Of the three solid red salamander varieties, which two varieties have mutations in the same gene?

A) a & b

B) a & c

C) b & c

D) all three mutations of different genes

E) all three mutations of same gene

C

Referring to the previous question (crosses are shown again below), the F1 offspring of cross 1 (a x b) were then crossed to the F1 offspring of cross 3 (b x c). What proportion of the offspring of this cross would be expected to be solid red?

Cross # Genotypes crossed F1 phenotype

1. a x b black with red spots

2. a x c solid red

3. b x c black with red spots

A) all solid red

B) 1/4 red

C) 7/16 red

D) 9/16 red

E) none red

A

Flower color in a certain plant is determined by two genes, B and D. The dominant B allele is necessary for conversion of a colorless precursor to a blue pigment. Thus, bb homozygotes have white flowers. The dominant D allele causes the blue pigment to degrade, thus even B_ D_ plants have white flowers. Homozygous dd plants do not degrade the blue pigment. From the cross Bb Dd x bb dd, what fraction of the plants will have white flowers?

A) 3/4

B) 13/16

C) 1/2

D) 1/4

E) 3/16

A

A researcher is studying coat color in guinea pigs. From the following crosses between guinea pigs with sepia coats (S), cream coats (C) and albino coats (A), the following results were obtained:

Cross S C A

1. C x C 0 3/4 1/4

2. S x S 3/4 1/4 0

3. S x S 3/4 0 1/4

4. S x C 1/2 1/4 1/4

5. C x A 0 1/2 1/2

Which of the following is the best explanation for the inheritance pattern of these three coat colors?

A) Three alleles of a single gene; sepia is dominant to cream, cream is dominant to albino

B)Two alleles, cream and albino, of a single gene. Sepia is due to incomplete dominance

C) Two different genes; sepia is epistatic to cream.

D) Variable expressivity of a single coat color gene

E) Environmental influences on coat color

b

Referring to the crosses in the previous question, which are repeated below, if you crossed one of the cream (C) parents in cross #1 with one of the sepia (S) parents in cross #3, what offspring ratios would you expect?

Cross S C A

1. C x C 0 3/4 1/4

2. S x S 3/4 1/4 0

3. S x S 3/4 0 1/4

4. S x C 1/2 1/4 1/4

5. C x A 0 1/2 1/2

A) 1/2 sepia, 1/2 albino.

B) 1/2 sepia, 1/4 cream, 1/4 albino.

C) 1/2 cream, 1/4 sepia, 1/4 albino

D) 3/4 sepia, 1/4 albino.

E) 9/16 sepia, 3/16 cream, 4/16 albino.

D

In a particular plant, flower color is determined by the following pathway, where genes A, B, and C encode pathway enzymes :

A B C

white------> yellow -------> orange --------> red

Assuming these genes assort independently, and show simple dominance, what fraction of the offspring of the cross Aa Bb Cc x aa bb cc would have red flowers?

A) 27/64

B) 3/8

C) 1/4

D) 1/8

E) none

c

In a particular plant, flower color is determined by the following pathway, where genes A, B, and C encode pathway enzymes (same pathway as previous question):

A B C

white------> yellow -------> orange --------> red

What fraction of the cross Aa Bb Cc x aa bb cc (same cross as previous question) would have yellow flowers?

A) 27/64

B) 3/8

C) 1/4

D) 1/8

E) none

b

Tortoiseshell cats result from X-inactivation of heterozygotes carrying different alleles of an X-linked gene affecting coat color. The O allele of the gene results in black fur, and the o allele results in orange fur. A black female cat has a daughter who is a tortoiseshell cat. What was the coat color of the father?

a) tortoise shell

b) orange

c) black

d) either black or orange

a

A black female cat has a daughter who is a tortoiseshell cat (same cross as previous question). What is the chance that an orange cat of either sex would be produced from this cross?

A) 0

B) 1/8

C) 1/4

D) 1/2

A

Hemophilia is an example of a recessive X-linked mutation. A woman has a child with hemophilia. Her husband does not have hemophilia, neither of her parents have hemophilia, and none of her four grandparents have hemophilia. From which of her four grandparents did the woman inherit the hemophilia allele?

A) maternal grandma

B) maternal grandpa

B) paternal grandpa

C) paternal grandma

D) new mutation

b

In an experiment we discussed in class, two true-breeding fully homozygous parental tobacco lines that differed in the length of their corollas (petals) were crossed and followed over several generations. Among their descendants, which generation(s) showed only environmental variation, and not genetic variation?

A) f1 & f2

B) f1

C) f2

D) neither

A

Translocations involve:

A) The exchange of segments between different chromosomes

B) Inversion of a chromosome segment.

C) Duplication of a chromosome segment

D) Deletion of a chromosome segment

E) Nondisjunction of chromosomes.

A

Albinism in humans is always recessive. Two albinos marry and have four normal, non-albino children. What is the most likely explanation of this family?

A) The parents carry mutations in different genes causing albinism

B) Chromosome nondisjunction occurred in one of the parents

C) Albinism must be sex linked, and can't be inherited from the father's side

D) Albinism in this family is due to incomplete dominance

A

Bacteriophage radioactively labeled with 32P were used to infect bacterial cells, the infected cells were sheared in a blender, and then centrifuged. Where was the radioactive 32P was found at the end of the experiment, after centrifuging?

A) In the pellet at the bottom of the tube, with the bacterial cells

B)In the supernatant liquid with the bacteriophage particles

C) Equally in the cell pellet and the supernatant

D) in neither the pellet nor the supernatant

E

Which of the following took an X-ray diffraction photograph that provided crucial evidence that helped Watson and Crick determine the DNA structure?

A) Maurice Wilkins

B) Erwin Chargaff

C) Oswald Avery

D) Alfred Hershey

E) Rosalind Franklin

A

The controversial "three-parent family" technique is a method for

A) Curing diseases caused by defective mitochondrial genomes

B) Identifying disease-causing genes by their location on the chromosome

C) Curing cystic fibrosis

D) Preventing childhood leukemia

E) Creating genetically engineered "super humans."

C

New alleles causing X-linked colorblindness are most often caused by:

A) Mutations causing an X-chromosome photoreceptor gene to become a pseudogene

B) Translocations involving an X-chromosome photoreceptor gene and a photoreceptor gene on chromosome 7.

C) Unequal crossing-over in a linked family of photoreceptor genes located on the X-chromosome.

D)Mutation-selection equilibrium.

E) Natural selection due to our modern lifestyle.

C

Sperm cells of domestic cats contain 2.41 picograms of DNA. How many picograms of DNA would be found in a cell in a somatic cell in the cat's body that was in G2 of mitosis?

A) 2.41 picograms

B) 4.82 picograms

C) 9.64 picograms

D) 19.28 picograms

E) 38.56 picograms

D

The yeast genome is approximately 12 x 106 bp in length. Assuming that each nucleosome has 146 bp of DNA wrapped around it, and the spacer length is approximately 60 bp, about how many molecules of histone H3 would you expect to find associated with yeast chromatin?

A) 12,000

B) 24,000

C) 60,000

D) 120,000

E) 600,000

b

Rough eyes (ro), brevis bristles (bv), and ebony body (e) are three recessive mutations in Drosophila. A wild-type female fly heterozygous for mutations in all three genes was crossed with a male fly with rough eyes, brevis bristles, and an ebony body. The following offspring were obtained:

Phenotypes Number

ro+ e+ bv 158

ro e+ bv+ 614

ro e+ bv 82

ro+ e bv 636

ro+ e+ bv+ 10

ro+ e bv+ 108

ro e bv+ 176

ro e bv 16

TOTAL : 1800

Which of the following is the correct genotype of the female parent, disregarding order of the genes on the chromosome?

A) ro+ e+ bv+/ro e bv

B) ro e+ bv+/ro+ e bv

C) ro+ e bv+/ro e+ bv

D) cant be determined

a

Rough eyes (ro), brevis bristles (bv), and ebony body (e) are three recessive mutations in Drosophila. A wild-type female fly heterozygous for mutations in all three genes was crossed with a male fly with rough eyes, brevis bristles, and an ebony body. The following offspring were obtained:

Phenotypes Number

ro+ e+ bv 158

ro e+ bv+ 614

ro e+ bv 82

ro+ e bv 636

ro+ e+ bv+ 10

ro+ e bv+ 108

ro e bv+ 176

ro e bv 16

1800

What is the correct order for these three genes?

A) e-- ro-- bv

B) ro-- e-- bv

C) ro-- bv--e

D) cant be determined

A

Rough eyes (ro), brevis bristles (bv), and ebony body (e) are three recessive mutations in Drosophila. A wild-type female fly heterozygous for mutations in all three genes was crossed with a male fly with rough eyes, brevis bristles, and an ebony body. The following offspring were obtained:

Phenotypes Number

ro+ e+ bv 158

ro e+ bv+ 614

ro e+ bv 82

ro+ e bv 636

ro+ e+ bv+ 10

ro+ e bv+ 108

ro e bv+ 176

ro e bv 16

1800

Which phenotypic class includes only single cross-overs between the genesroande?

A) ro+ e+ bv

B) ro e+ bv

C) ro+ e bv

D) ro+ e+ bv+

E) ro+ e bv+

b

Rough eyes (ro), brevis bristles (bv), and ebony body (e) are three recessive mutations in Drosophila. A wild-type female fly heterozygous for mutations in all three genes was crossed with a male fly with rough eyes, brevis bristles, and an ebony body. The following offspring were obtained:

Phenotypes Number

ro+ e+ bv 158

ro e+ bv+ 614

ro e+ bv 82

ro+ e bv 636

ro+ e+ bv+ 10

ro+ e bv+ 108

ro e bv+ 176

ro e bv 16

1800

What is the map distance between ro and bv?

A) 1.4

B) 12

C) 20

D) 32

E) 50

D

Rough eyes (ro), brevis bristles (bv), and ebony body (e) are three recessive mutations in Drosophila. A wild-type female fly heterozygous for mutations in all three genes was crossed with a male fly with rough eyes, brevis bristles, and an ebony body. The following offspring were obtained:

Phenotypes Number

ro+ e+ bv 158

ro e+ bv+ 614

ro e+ bv 82

ro+ e bv 636

ro+ e+ bv+ 10

ro+ e bv+ 108

ro e bv+ 176

ro e bv 16

1800

If these three genes assorted independently, we would have expected:

A) four phenotypic classes

B) a 9:3:3:1 ratio phenotypes

C) more than 8 classes

D) 225 flies in each class

E

For the following two questions, consider the following map:

25 cM 25 cM

A——————B—————C

From the testcrossA B C/a b c x a b c/a b c, what proportion of offspring would be the result of a double cross-over in the heterozygous parent?

A) 1%

B) 2%

C) 4.5%

D) 5%

E) 6.25%

D

25 cM 25 cM

A——————B—————C

From the testcrossA B C/a b c x a b c/a b c, what proportion of offspring would have the A B C phenotype?

A) 64%

B) 56.3%

C) 32%

D) 28.1 %

E) 25%

b

The next two questions refer to the following cross. Female fruit flies heterozygous for the recessive traits striped body (sr), curly wings (cu) and forked bristles (f) was test crossed to striped, curly, forked males, and the following results were obtained for the progeny:

Body Wing Bristles # of Flies

normal normal normal 30

normal normal forked 30

normal curly normal 220

normal curly forked 220

striped normal normal 220

striped normal forked 220

striped curly normal 30

striped curly forked 30

1000

Which, if any, of these genes are linked?

A) all three are linked

B) sr & cu linked

C) sr & f linked

D) cu & f linked

E) all three genes assort independently

c

Female fruit flies heterozygous for the recessive traits striped body (sr), curly wings (cu) and forked bristles (f) was test crossed to striped, curly, forked males, and the following results were obtained for the progeny:

Body Wing Bristles # of Flies

normal normal normal 30

normal normal forked 30

normal curly normal 220

normal curly forked 220

striped normal normal 220

striped normal forked 220

striped curly normal 30

striped curly forked 30

1000

Based on these results (same as the previous question), what is the correct map distance between two linked genes?

A) 5

B) 6

C) 12

D) 20

E) none are linked

b

In a certain plant, flower color is determined by the biochemical pathway below. If both red and yellow pigments are present, the flowers are orange.

{white -A- white- B- red or -A- white- C- yellow.}

Genes A and B are linked, at a distance of 10 cM. Gene C assorts independently.

A b/a B, Cc × a b/a b, cc

What fraction of the offspring from the cross above will have red flowers?

A) 1.25%

B) 2.5%

C) 4.5%

D) 10%

E) 33.75%

B

n corn plants, colored kernels are due to accumulation of anthocyanin pigments, while kernels lacking anthocyanins are yellow. The BZ gene controls the color of the anthocyanin pigments produced. Kernels with at least one BZ allele are purple, while kernels homozygous for the recessive bz allele are a brownish-gold "bronze" color. The I gene is a dominant inhibitor of all anthocyanin production, resulting in yellow kernels regardless of the BZ gene allele present, while plants homozygous for the recessive i allele have a color determined by the BZ alleles. A plant heterozygous for alleles of BZ and I was testcrossed to a bz bz i i plant, and the following results were obtained:

35 bronze

465 purple

500 yellow

1000 total

BZ and I are linked. What is the map distance between them?

A) 3.5

B) 7

C) 9.3

D) 46.5

E) 50

C

Which of the following principles or methods was most important for identifying the SIAMESE gene in Dr. Larkin's lab?

A) population allele frequencies

B) independent assortment

C) linkage

D) synteny

E) x-ray diffraction

C

Most black bears (Ursus americanus) have black or brown coats, but in some populations in British Columbia, white bears are occasionally seen. White color results from a single base-pair change in which the adenine (A) at one position in the wild-type MC1R gene (black or brown coat color), is substituted by a guanine (G) in the recessive mc1r allele, resulting in the recessive white coat phenotype. Genotyping of bears in British Columbia for this codominant allele gave the following results:

GenotypeNumber

AA 42

AG 24

GG 21

What is the frequency of the G allele, which confers the white phenotype, in this population?

A) 0.695

B) 0.491

C) 0.379

D) 0.240

E) 0.210

E

The next two questions refer to the following population of cats:

Full color (D) in domestic cats is dominant over dilute color (d). Of 325 cats observed, 194 have full color and 131 have dilute color. Assuming that this population of cats is in Hardy-Weinberg equilibrium, what is the frequency of the dilute (d) allele in the population?

A) 11.4

B) 0.211

C) 0.403

D) 0.597

E) 0.635

C

A cat from the population described in the previous question that has a full colored coat mates with a cat with a full colored coat whose parents were both full colored and whose brother has the recessive dilute phenotype. What is the chance that a kitten from this cross would have a dilute coat? (Hint: Draw a pedigree.)

A) 0.777

B) 0.517

C) 0.130

D) 0.097

E) 0.077

A

A particular gene has two alleles, the dominant allele A and the recessive allele a. In environment #1, the dominant A allele is selected against with selection coefficient s=0.1, and aa homozygotes are the most fit genotype. In environment #2, aa homozygotes are selected against with selection coefficient s=0.1, and genotypes with at least one A allele (A_) are the most fit genotype. Thus in environment #1, the frequency of the dominant allele will decrease over time, while in environment #2, the a allele will decrease in frequency over time.

Which allele will be eliminated from its population most rapidly, the A allele in environment #1, or the a allele in environment #2?

(Hint: This is essentially the same as the example with moths from class.)

A) The A allele in environment #1 will be eliminated most rapidly.

B) The a allele in environment #2 will be eliminated most rapidly.

C) Both will be eliminated at the same rate.

D)No prediction can be made, since the populations are not in Hardy-Weinberg equilibrium

C

A particular species of plant requires bees for pollination and seed production. The plant has flowers of two colors, orange and blue, determined by alleles of a single gene (blue is dominant). Two different species of bees pollinate the plants. One species of bee prefers to visit blue flowers, rarely visiting (or pollinating) orange flowers. The other species of bee prefers orange flowers, and rarely visits blue flowers. Both types of flower produce equal numbers of seeds. Which exception to H-W equilibrium does this example illustrate? (Hint: What biological process does pollination represent, from the plants' point of view?)

A) small population

B) migration

C) non-random mating

D) mutation

E) natural selection

c

An experiment with sunflowers tested how a particular recessive allele a affected reproduction, and the following results were obtained:

Genotype average number of seeds per plant

A_ 170

aa 20

What is the selection coefficient for the aa genotype?

A) 150

B) 20

C) 0.88

D) 0.20

E) 0.12

A

At mutation-selection equilibrium, the frequency of an unfavorable recessive allele a in a population is 0.001. The dominant allele A mutates to the recessive a allele at a rate of 1 x 10-6 per generation. What is the selection coefficient (s) for the a allele?

A) 1

B) 0.1

C) 0.01

D) 0.001

E) 1 e -6

C

Most RNA viruses are have single-stranded RNA genomes, but some, like bluetongue virus, have double-stranded RNA genomes. Of the viruses below, which one must be bluetongue virus?

% of Nucleotides

Virus A U G C T

#1 32 18 18 32 0

#2 25 25 33 17 0

#3 28 28 22 22 0

#4 22 0 28 28 22

#5 36 18 28 18 0

A) virus 1

B) virus 2

C) virus 3

D) virus 4

E) virus 5

b

Consider two viruses with double-stranded DNA genomes. For both viruses, the pure double-stranded DNA is infectious to cultured human cells, but single-stranded DNA produced by heating, which break the H-bonds between base-pairs, is not infectious. Virus A becomes non-infectious when heated to 68oC, while Virus B remains infectious unless heated above 74oC. Which virus has a higher percentage of G-C base-pairs in its genome?

A) virus A

B) virus B

C) cant tell from exprmt

e

Which of the following is not true of the HIV virus?

A) The viral genome in the virus particle is RNA.

B)A DNA copy of the virus genome is inserted into the host cell genome.

C) The virus particle contains the enzyme reverse transcriptase.

D) The virus particle contains lipids

E) all are true

E

A segment of human chromosome 6 has similar genes in the same order as part of dog chromosome 12. This conserved gene order between related species is called:

A) snp

B) haplotype

C) GWAS

D) linkage

E) synteny

D

In the study on evolution of feather lice on pigeons, what evidence was used to show that the observed color changes were heritable?

A)After 60 generations, the color of the lice had changed to match the color of the host's feathers.

B)They showed that the birds were more likely to remove lice that differed in color from their feathers.

C)They cut some bristles on the lice, giving them a "haircut"

D)They showed that the color phenotype of the offspring was similar to that of the parents.

b

The article "Human Genetic Variation, Shared and Private" talked about the discovery that moderately rare alleles (q > 0.5%) tend to be shared among most human populations ("public alleles"), while very rare alleles (q < 0.5%) tend to be restricted to specific human populations ("private alleles").

The very rare "private" alleles (q <0.5%) restricted to specific human populations are thought to:

A) Have been present in the ancestral human population

B) Have originated during recent rapid expansion of human populations

C)Have been nearly eliminated by natural selection.

D)Be maintained in the population due to mutation/selection equilibrium.

E) Be the source of major phenotypic differences among populations.