BIOLOGY 1005 - Multiple alleles means that there are more

Multiple alleles means that there are more than 2 alleles which can be inherited in a population. Remember though, each individual only receives 2 alleles, one from each parent.

ABO blood typing uses 3 alleles:

• Which two are dominant? _________ Write the two dominant allele genotypes, using the capital letter I, and then a superscript for each of them. ______________________

• Which allele is recessive? __________ Write the genotype (letters) for the recessive trait, beginning with the lower case i. ____________

Complete a Punnett square for the following scenario:

Mom is heterozygous for blood type B and Dad is blood type AB.

(make sure to put the parent alleles in the correct places outside of the square, and fill in each of the boxes within the square)

• Place the punnett square in your word document and answer the following questions:

• What are all the possible blood types of their offspring? __________________________

• What is the probability of their child having blood type AB? ________ Blood type O? _____________

Part IV: Deleterious Recessive Traits

A recessive trait is one where the individual must have two recessive alleles for the phenotype of the trait to be visible. The recessive trait can be carried from generation to generation through heterozygous individuals. A person who is heterozygous for a harmful or deleterious trait is said to be a "carrier" of the trait.

If an individual receives 2 recessive alleles for a harmful or deleterious trait, let us say for our problem below, they will have the "illness".

Solve the problem of the parents provided below. Perform the Punnett Square and answer the questions below. Only the answers are required in the answer sheet that you upload.

Mom and Dad are both heterozygous for the harmful or deleterious recessive trait.

• What is the probability of their offspring having the illness? ____________%
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• What is the probability of their offspring being a "carrier"? _____________%