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amethystwhale496Lv1

28 Sep 2019

1. A dominant gene (H) produces wire-haired texture in dogs; its recessive allele (h) produces smooth hair. Two heterozygous wire-haired individuals were crossed and their F1 progeny testcrossed. Determine the expected genotype and phenotype rations among the testcross progeny. Note: in a testcross, an individual with an unknown genotype is crossed with a homozygous recessive individual.

2. A white guinea pig, whose parents were black, is closed with a black guinea pig whose male parent was white and whose female parent was black. Two white offspring result. Determine the genotypes of all individuals mentioned. About which individuals is there some doubt?

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Reid WolffLv2

28 Sep 2019

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Related questions

1. (8 points) Anhydrotic ectodermal dysplasia is an X-linked recessive disease in cattle, causing tooth abnormalities and hairlessness. Arachnomelia is an autosomal recessive condition that causes spider legs in newborn calves. Use âDâ to indicate the dominant, normal teeth and hair in cattle and âdâ for the dysplasia. Use âLâ for normal legs and âlâ for spider legs. Suppose a heifer having normal teeth and hair and normal legs but whose sire had dysplasia and spider legs is backcrossed to her sire.

a. What are their genotypes?

b. What are the genotypes, phenotypes, and genotypic and phenotypic proportions we expect in their progeny?

2. (6 points) In German Shepherds, hemophilia A is an X-linked recessive disease, affecting the blood clotting times in dogs having the disease. Use â+â to indicate the normal, normal blood clotting time allele and âaâ for the hemophilia allele. A bitch (female) who has normal blood clotting times and whose sire (male) had hemophilia A is mated with a sire with normal blood clotting times but whose sire also had hemophilia A.

a. What are the genotypes of the 4 dogs described in the problem?

b. What are the genotypes, phenotypes, genotypic and phenotypic proportions you would expect to observe in the puppies produced from this cross?

3. (8 points) In turkeys, inhibited feathering is a sex-linked dominant gene (F). Use âfâ to denote the normal feathering allele. Suppose a bald hen (female) is crossed with a normally feathered rooster.

a. What are the genotypes of the two birds described?
b. What are the genotypes, phenotypes, genotypic and phenotypic proportions expected in the F1 progeny? c. What will be the genotypes, phenotypes and proportions produced when the F1 males are backcrossed?

4. (8 points) In guinea pigs, short hair (H) is dominant to long hair (h) and the heterozygous condition when you cross a yellow coat (CY) and white coat (CW) gives you a cream coat. These two loci are located on different chromosomes. A heterozygous short-haired cream guinea pig is crossed to a long-haired white guinea pig.

a. What are the genotypes, phenotypes and proportions of the pups (baby guinea pigs) produced?

b. What are the genotypes, phenotypes and proportions expected if we crossed the heterozygous short- haired cream guinea pig with a heterozygous short-haired yellow guinea pig?

blushlion529

For each problem I need to know the following plus whateverspecifics the problem requests:

Key: (Which symbol stands for which allele) â Use the sameletter for a gene using a capital to designate dominant and lowercase to show recessive.

Parental genotypes

Possible gametes for each parent

The Punnett Square

1. In guinea pigs black coat color is dominant to brown coatcolor. A black guinea pig (from a long line of black guinea pigs)is bred to a brown guinea. If one of these offspring is then bredto a different brown guinea pig, what are the expected genotypesand phenotypes of their offspring?

2. In pea plants tall stems are dominant to short stems andpurple flowers are dominant to white flowers. A true breeding plantwith tall stems and white flowers is crossed with a true breedingplant having short stems and purple flowers. The offspring fromthis cross are grown up and allowed to interbreed. What are theexpected genotypes and phenotypes of their offspring?

3. In dogs, black is dominant to golden. You have a blackLabrador retriever you would like to stand at stud, but first youwant to know if it is homozygous black or heterozygous. You make atestcross to determine this. What are the expected genotypes andphenotypes if your dog is heterozygous? If it is homozygous?

4. Color-blindness is X-linked in humans. A color-blind manmarries a woman whose father was color-blind. What are the expectedgenotypes and phenotypes of their children?

pucemole610

Diagram a cross between a true breeding pea plant that produces yellow seeds (G/G) with one that produces green seeds (g/g). Carry the cross out to the F2 generation. Answer the following questions:

What was the F1 genotype and phenotype?

What kinds of gametes could the F1 individuals produce?

What were the F2 genotypes and phenotypes, and in what ratios would you expect each to occur?

Diagram a cross between a true breeding pea plant that produces round seeds and purple flowers, with one that produces wrinkled seeds and white flowers. (Round and purple are the dominant traits.) Carry the cross out to the F2 generation. Answer the following questions:

What are the P1 genotypes?

What is the F1 genotype and phenotype?

What kinds of gametes will the F1 individuals produce?

What are the F2 genotypes and phenotypes?

What genotypic and phenotypic ratios are expected in the F2 progeny?

Diagram a cross between a true breeding pea plant that produces yellow seeds (G/G) and purple flowers (W/W) with one that produces green seeds (g/g) and white flowers (w/w). Carry the cross out to the F2 generation. Answer the following questions:

What was the F1 genotype and phenotype?

What kinds of gametes could the F1 individuals produce?

What were the F2 genotypes and phenotypes, and in what ratios would you expect each to occur?

Diagram a test cross of the F1 individuals from the question above, with the homozygous recessive parent strain. What genotypes and phenotypes would you expect in the testcross progeny, and in what ratios?

If you had a fruitfly with phenotype A, what test would you make to determine if it was Aa or AA? Explain the different outcomes expected if the fly in question is AA or Aa.

If individuals of genotype AaBbCc are intercrossed:

How many different genotypes can occur in their progeny? How many different phenotypes can occur in the progeny?