Genetics Extensions of Mendelian Inheritance

2

With respect to the genes that influence comb shape, how many different types of gametes can an individual of the genotype rrPp make?

Dominant

A chicken heterozygous for the Creeper allele has a phenotype of shortened wings and legs. When looking at the phenotype, the Creeper allele is ___________ to the normal allele.

HhZZ male; hhZW female

A hen-feathered male and a hen-feathered female are mated. The male offspring were found to be 50% cock-feathered and 50% hen-feathered. What were the genotypes of the male and female parents?

True

A lethal gene could be recessive, dominant or conditional, depending on the locus.

Codominance

A male with blood type B and a woman with blood type A have a child with blood type AB. The blood type of the child is possible due to what type of inheritance pattern?

0.66

A man and a woman, both carriers of the sickle cell allele (HbS), have five children. The first two children are unaffected, the third child has sickle cell anemia, and the fourth and fifth children are unaffected. What is the probability that a phenotypically normal sixth child will be a carrier?

0.25

A man and a woman, both carriers of the sickle cell allele (HbS), have five children. The first two children are unaffected, the third child has sickle cell anemia, and the fourth and fifth children are unaffected. What is the probability that a sixth child will have sickle cell anemia?

0.40

A man and woman have five children. What is the probability of this couple having four unaffected (either HbAHbA or HbAHbS ) and one affected child if both parents are carriers?

Both parents are HbAHbS

A man and woman have five children; four are phenotypically normal and one child has sickle cell anemia. What are the most likely genotypes of the mother and father?

True

A single copy of an allele showing a complete dominance typically masks the effects of a recessive allele

IAIB

A son has the blood-type A (IAi). The father of this boy is known to be blood type AB. Which of the following is not a possible genotype for the mother?

IBi

A son has the blood-type B (IBi). The father of this boy is known to be blood type AB. In order for the son to donate blood to his mother, what must be the mother's genotype?

True

A wild allele is one that is thought to contribute to the most common phenotype of a natural population.

False

An example of overdominance is polydactyly in humans.

The R and P must both be present to produce a walnut comb.

Concerning comb shape in chickens, which of the following is true?

False

Dominant alleles are always the result of gain of function mutations

True

Epistasis is an example of gene interaction.

The Creeper allele is lethal in the homozygous state.

Genotyping of a clutch of 98 chicks shows that 32 are normal and 66 are heterozygous for the Creeper allele. What would explain the lack of Creeper homozygotes being present in the flock?

O

If a person is blood type O and needs a transfusion, which of the following blood types could act as a donor?

True

If a person is heterozygous for a recessive disease allele they normally possess 50% of the normal amount of protein

The progeny are genotypically and phenotypically identical to the parent.

If a true breeding strain of sweet pea is allowed to self-fertilize which of the following statements is true?

1/3

If two Creeper chickens are mated, what fraction of the offspring will be normal?

No, one of the parents would have to be homozygous for the Creeper allele.

If two chickens are crossed and they produce 100 offspring, is it probable for all of the F1 progeny to show the Creeper phenotype?

CRCW DRDW

In a different plant species from the example given, flower color is controlled by two genes that contribute equally to pigmentation in the final flower color. The more "R" alleles, the more pigmentation, such that only plants with the genotype CRCR DRDR have red flowers, and only plants with the genotype CWCW DWDW have white flowers. Plants with three "R" alleles produce 75% as much pigmentation as CRCR DRDR plants and have dark pink flowers. Plants with three "W" alleles produce 25% as much pigmentation as CRCR DRDR plants and have light pink flowers. Plants with an equal number of "R" and "W" alleles produce 50% as much pigmentation as CRCR DRDR plants and have pink flowers. A red flowering plant was mated to a white flowering plant and all of the F1 progeny had pink flowers. These pink flowered F1 plants were allowed to self-fertilize to produce F2 progeny. What is the genotype of the F1 plants that produced pink flowers? (Hint: draw Punnett squares to determine the F1 and F2 genotypes and phenotypes.)

dominant; recessive

In males the hen-feathered phenotype is __________ and cock-feathered phenotype is ____________.

chc x chc

In rabbits coat color is controlled by a single gene with 4 alleles: cC>cch>ch>c. cC = full color, cch= chinchilla, ch= Himalayan, c= colorless (albino rabbits). The Himalayan allele which results in a black nose, ears and paws is only functional below 30 degrees Celsius. At higher temperatures the protein doesn't function and the rabbits are albino. You cross two Himalayan rabbits. When you raise the progeny at 32 degrees Celsius, you get all albino bunnies. If you raise them at 25 degrees Celsius you get a 3:1 ratio of Himalayan to albino bunnies. What were the genotypes of the two parents?

True

Patients with PKU who injest some phenylalanine fail to convert that phenylalanine into tyrosine. This failed conversion of phenylalanine can lead to problems in tooth development, neural function, and normal urine production. The wide variation of phenotypic traits observed is an example of pleiotropy.

False

Recessive alleles usually cause an increase in functional protein expressions

xaxa,xAya

Recombination can occur in a female between the two X chromosomes and in a male between the X and the Y chromosomes. This recombination can lead to pseudoautosomal inheritance of genes on the X and Y chromosomes. A male and a female have 4 children. Both of the daughters are genotype XaXA, one son has the genotype XaYa, and the other son has the genotype XaYA. What are the genotypes of the parents?

5

Referring to the crosses described in the previous question, how many different flower colors will be present in the F2 population?

CRCR DRDW, CWCR DRDR

Referring to the crosses described in the previous questions, what genotypes in the F2 population will produce dark pink flowers?

CRCW DWDW, CWCW DRDW

Referring to the crosses described in the previous questions, what genotypes in the F2 population will produce light pink flowers?

CRCW DRDW, CRCR DWDW, CWCW DRDR

Referring to the crosses described in the previous questions, what genotypes in the F2 population will produce pink flowers (flowers that are true pink, not dark pink or light pink)?

6,4,4,1,1

Referring to the crosses described in the previous questions, what is the phenotypic ratio of the F2 plants? (Hint: draw Punnett squares to determine the F1 and F2 genotypes and phenotypes.)

AxB

The ABO Blood types in humans are controlled by one gene with 3 alleles. Is it possible for a couple to produce progeny with all four blood types? If so which of the following would describe their phenotypes?

True

The most prevalent alleles in a population are called wild type alleles

False

The pedigree below shows inheritance of the dominant trait polydactyly. Individual II-4 has 6 fingers on their right hand, while individual IV-3 has an extra toe on each foot. Individual III-2 has 10 fingers and 10 toes. These individuals show a range of incomplete penetrance.

False

The term penetrance means the range of the mutant phenotype, while expressivity means the proportion of individuals that have the gene actually express it.

2 red-eyed females : 1 red-eyed male : 1 cream eyed male

The white gene is located on the X chromosome and the cream gene is located on an autosome. Bridges reached this conclusion from the result of a mating between red-eyed females (CcaXw+Xw-e) and red-eyed males (CcaXw+Y). What would have been the outcome of this mating if white and cream were still different genes but both were located on the X chromosome? Hint: the female genotype is Xw+ C Xw-e ca and the male genotype is Xw+ C Y.

Norm of Reaction

Three populations of genetically identical fruit flies were raised at either 18°C, 23°C, or 39°C. The number of facets in the adult compound eyes were counted and resulted in 950, 840, and 775 for each of the respective temperatures. This experiment is an example of

CCpp x CCpp

Two true breeding white flowered strains are mated and all of the progeny have white flowers. Which cross would give this result?

C-cch-ch-c

What is the hierarchy of dominance for the four alleles that control fur pattern in rabbits?

The protein product of the ch allele is only active at lower temperatures

What is the most likely explanation for why himalyan rabbits have dark fur only at their extremities?

rrPP

Which genotype, when mated to a rose comb chicken, will produce progeny that are 50% walnut comb and 50% pea comb?

An inheritance pattern in which the alleles of one gene mask the phenotypic effects of different gene.

Which is the most complete and accurate definition of epistasis?

They are phenotypically expressed in only one sex.

Which of the following is true regarding sex limited traits?

Neither the A or B antigens are present on type O red blood cells.

Why is an individual with blood type O considered a universal donor?

Walnut=R_P_, Single=rrpp, Rose=R_pp, Pea=rrP_

You cross a rose comb chicken with a pea comb chicken and get all walnut comb progeny. You then cross two of the walnut combed chickens from the F1 generation and get 9 walnut combs: 3 rose combs: 3 pea combs : 1 single comb. Which of the following would best explain these results? Underline means any allele could be present. For example R_ could be RR or Rr

Mate with HhZW female and get a hen-feathered:cock-feathered ratio of 1:1 in males

You have a hen-feathered male and you want to determine whether it is heterozygous (HhZZ) or homozygous (HHZZ). Which of the following mating outcomes would allow you to conclude that you have a heterozygous hen-feathered male?

50% grey, 25% chinchilla, 25% Albino

You have found a population of wild rabbits with a uniform grey coat color. You suspect that the grey allele is recessive to normal coat color and dominant to chinchilla. Predict the outcome of the following matings if your hypothesis is correct. Chinchilla (cch c) x Grey (cg c)

50% grey, 25% chinchilla, 25% Himalayan

You have found a population of wild rabbits with a uniform grey coat color. You suspect that the grey allele is recessive to normal coat color and dominant to chinchilla. Predict the outcome of the following matings if your hypothesis is correct. Chinchilla (cch c) x Grey (cg ch)

100% grey

You have found a population of wild rabbits with a uniform grey coat color. You suspect that the grey allele is recessive to normal coat color and dominant to chinchilla. Predict the outcome of the following matings if your hypothesis is correct. Chinchilla (cch cch) x Grey (cg cg)

50% full color, 50% grey

You have found a population of wild rabbits with a uniform grey coat color. You suspect that the grey allele is recessive to normal coat color and dominant to chinchilla. Predict the outcome of the following matings if your hypothesis is correct. Full color (C ch) x Grey (cg cg)

100% full color

You have found a population of wild rabbits with a uniform grey coat color. You suspect that the grey allele is recessive to normal coat color and dominant to chinchilla. Predict the outcome of the following matings if your hypothesis is correct. Normal (full) color (C C) x Grey (cg cg)

CcaXw-eXw-e

You have mated a red-eyed female fly of the genotype CcaXw+Xw-e to an eosin eyed male of the genotype CcaXw-eY. Which F1 genotype does not correspond to a red-eyed female?

caca Xw-eXw-e

You have mated a red-eyed female fly of the genotype CcaXw+Xw-e to an eosin eyed male of the genotype CcaXw-eY. Which F1 genotype will correspond to a female with cream eye color?

CCXw-eY

You have mated a red-eyed female fly of the genotype CcaXw+Xw-e to an eosin eyed male of the genotype CcaXw-eY. Which F1 genotype will correspond to a male with light eosin eyes?

ccPp x Ccpp

You have two strains of white flowered sweet peas that, when mated, produce F1 progeny with a phenotypic ratio of 3 white flowered plants: 1 purple flowered plant. What are the genotypes of the parents in this mating?

CcPp

You have two strains of white flowered sweet peas that, when mated, produce F1 progeny with a phenotypic ratio of 3 white flowered plants: 1 purple flowered plant. What is the genotype of the purple flowered F1 progeny?

The purple allele is lethal in the homozygous state

You identify a rare purple plumed parrot. When you cross the parrot to a true breeding white parrot, you get 1/2 white and 1/2 purple parrots. When you cross two purple parrots you get 1/3 white parrots and 2/3 purple parrots. Which of the following best explains this result?