Multiple Alleles

Multiple Alleles

Multiple Choice

Question 1 from homework: Hair type shows incomplete dominance. Show a cross for a man with one curly hair allele and one straight hair allele and a woman who is homozygous for curly hair. What is the phenotypic ratio?

• 1:2:1

• 2:2:0

• 0:2:2

• 0:4:0

Multiple Choice

Question 3b from homework: The Four O'clock plant has

two alleles for flower color: red and white. These show incomplete dominance. Determine the expected offspring of a cross between a pink-flowered Four O'clock plant and a white flowered plant. What is the genotypic ratio?

• 1:2:1

• 2:2:0

• 0:2:2

• 0:4:0

Multiple Choice

Question 4 from homework: In horses, alleles for red and white hairs are codominant. Horses that are heterozygous have some red hairs and some white hairs and are called roan. Show a cross and ratios between two roan horses. What is the phenotypic ratio?

• 1:2:1

• 2:2:0

• 0:2:2

• 0:4:0

Multiple Choice

Question 5 from homework: In chickens, black and white feathers are codominant, and the heterozygous individuals are speckled (known as erminette). Show a cross between a black feathered chicken and a white feathered chicken. What percentage of the offspring are gray?

• 0%

• 25%

• 50%

• 100%

Multiple Choice

Question 7 from homework: A couple preparing for marriage have their blood types determined. Both individuals are type AB. They ask what types of blood their children may have. What percentage of the children are likely to have type A blood?

• 0%

• 25%

• 50%

• 100%

Multiple Choice

Question 9 from homework: A wealthy, elderly couple die together in an accident. Soon afterwards a man shows up to claim their fortune contending that he is their only son who ran away from home as a boy. Other relatives dispute this claim. Hospital records show that the deceased couple are blood type O and AB. The claimant (son?) to the fortune was type O.Is it possible that the man is actually their son?

• Yes, there is a 25% chance of type O blood.

• Yes, there is a 50% chance of type O blood.

• No, only blood type AB is possible.

• No, only blood types A or B are possible.

Multiple Choice

Problem 11b from homework: In rabbits, there are four alleles. C is the normal allele, and is dominant to everything; cch is chinchilla, and is dominant to everything except normal fur; ch is Himalayan, and is only dominant to albino; c is albino, and is recessive to everything. Do a rabbit cross between a rabbit who is albino, and one that is cch ch. What are the phenotypes of the offspring?

• 50% chinchilla, 50% Himalayan

• 50% chinchilla, 25% Himalayan, 25% albino

• 25% chinchilla, 50% Himalayan, 25% albino

• 25% chinchilla, 25% Himalayan, 50% albino