Exam 13: Mendel and the Gene

In rabbits,the homozygous CC is normal,Cc results in deformed legs,and cc results in very short legs.The genotype BB produces black fur,Bb brown fur,and bb white fur.If a cross is made between brown rabbits with deformed legs and white rabbits with deformed legs,what percentage of the offspring would be expected to have deformed legs and white fur?

Whenever the dominant allele of either (or both)gene A or gene B is present,red color is produced.A cross of AaBb × AaBb can be expected to yield how many red offspring out of 16? Assume the genes are not linked.

A heterozygous,but phenotypically wild-type fruit fly (gray body color and normal wings)was mated to a black fly with vestigial wings.The offspring had the following phenotypic distribution: Wild type,720;black-vestigial,780;black-normal,280;gray-vestigial,220.What conclusion is likely from these results?

A man who carries an allele of an X-linked gene will pass it on to _____.

When Mendel crossed yellow-seeded and green-seeded pea plants,all the offspring were yellow seeded.When he took these F₁ yellow-seeded plants and crossed them to green-seeded plants,what genotypic ratio is expected?

In humans,blue eyes are inherited as a recessive autosomal trait and color blindness is an X-linked recessive trait.A woman with blue eyes and normal color vision whose father was color blind marries a man who also has normal color vision.He has brown eyes but his mother had blue eyes.Which of the following do you expect to be true for their daughters?

Glucose-6-phosphate dehydrogenase deficiency (G6PD)is inherited as a recessive allele of an X-linked gene in humans.A woman whose father suffered from G6PD marries a normal man.(a)What proportion of their sons is expected to be G6PD? (b)If the husband was not normal but was G6PD deficient,would you change your answer in part (a)?

A man and woman are both of normal pigmentation,but both have one parent who is albino (without melanin pigmentation).Albinism is an autosomal (not sex-linked)recessive trait.What is the probability that their first female child will have albinism?

A black guinea pig crossed with an albino guinea pig produced 12 black offspring.When the albino was crossed with a second black animal,6 blacks and 6 albinos were obtained.What is the best explanation for this genetic situation?

A homozygous tomato plant with red fruit and yellow flowers was crossed with a homozygous tomato plant with golden fruit and white flowers.The F₁ all had red fruit and yellow flowers.The following phenotypes were obtained in the F₂: Red fruit and yellow flowers-41 Red fruit and white flowers-7 Golden fruit and yellow flowers-8 Golden fruit and white flowers-44 How many map units separate these genes?

Pseudohypertrophic muscular dystrophy is a human disorder that causes gradual deterioration of the muscles.Only boys are affected,and they are always born to phenotypically normal parents.Due to the severity of the disease,the boys die in their teens.Is this disorder likely to be caused by a dominant or recessive allele? Is its inheritance sex-linked or autosomal?

In humans,blue eyes are inherited as a recessive autosomal trait and color blindness is an X-linked recessive trait.A woman with blue eyes and normal color vision whose father was color blind marries a man who also has normal color vision.He has brown eyes,but his mother had blue eyes.Which of the following do you expect to be true for their sons?

In tigers,a recessive allele causes a white tiger (absence of fur pigmentation).If one phenotypically normal tiger that is heterozygous is mated to another that is phenotypically white,what percentage of their offspring is expected to be white?

Phenylketonuria is an inherited disease caused by a recessive autosomal allele.If a woman and her husband are both carriers,what is the probability that their first child will be a phenotypically normal girl?

In humans,ABO blood types refer to glyocproteins in the membranes of red blood cells.There are three alleles for this autosomal gene: IA,IB,and i.The IA allele codes for the A glycoprotein,The IB allele codes for the B glycoprotein,and the i allele doesn't code for any membrane glycoprotein.IA and IB are codominant,and i is recessive to both IA and IB.People with A type blood have the genotypes IAIA or IAi,people with type B blood are IBIB or IBi,people with type AB blood are IAIB,and people with O type blood are ii.If a woman with type AB blood marries a man with type O blood,which of the following blood types could their children possibly have?

Gray seed color in peas is dominant to white.Assume that Mendel conducted a series of experiments where plants with gray seeds were crossed among themselves,and the following progeny were produced: 302 gray and 98 white.(a)What is the most probable genotype of each parent? (b)Based on your answer in (a)above,what genotypic and phenotypic ratios are expected in these progeny? (Assume the following symbols: G = gray and g = white. )

Hemophilia is caused by several genetic factors;one,a recessive allele of an X-linked gene,is the subject of this problem.Assume that a man with hemophilia marries a normal woman whose father had hemophilia.What is the probability that they will have a daughter with hemophilia?

Snapdragons are flowers that come in a variety of colors,including red,pink,and white.A series of crosses with snapdragons having flowers of different colors produced the following results: Pink × pink: 27 pink,13 red,14 white Red × red: All red White × white: All white Pink × white: 29 pink,26 white Pink × red: 28 pink,27 red White × red: All pink Based on the results,what is the most reasonable explanation for the inheritance of these flower colors?

A recessive allele on the X chromosome is responsible for red-green color blindness in humans.A woman with normal vision whose father is color blind marries a color-blind male.What is the probability that this couple's first son will be color blind?

Assuming independent assortment for all gene pairs,what is the probability that the following parents,AABbCc × AaBbCc,will produce an AaBbCc offspring?