Mr. and Mrs. Canady have 8 children. Three of them have attached earlobes (recessive) like their father, and the other five have free earlobes like their mother. What are the genotypes of Mr. and Mrs. Canady? You may select more than one answer.

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Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]

A	Mr. Canady:Aa
B	Mr. Canady:aa
C	Mrs. Canady:Aa
D	Mrs. Canady:AA
E	They are both AA

Explanation:

Detailed explanation-1: -The answer is c) 50%. This can be visualized with a Punnett square. The individual with attached earlobes has the genotype ee and can only produce e alleles. The individual that is heterozygous with free earlobes has the genotype Ee and can produce both E and e alleles.

Detailed explanation-2: -If a person has a free earlobe, then its genotype would be either UU or Uu. If a person has an attached earlobe then its genotype would be uu. So, if parents (male as well as female) have free earlobes and offspring have attached earlobes, then surely both parents would be heterozygous for this trait.

Detailed explanation-3: -The probability of having offspring with free earlobes then is 3/4; for attached earlobes, it is 1/4.

Detailed explanation-4: -This means that the probability of an offspring having attached earlobes is 50%.

There is 1 question to complete.

AP BIOLOGY

HEREDITY

INCOMPLETE DOMINANCE