Question

Match the pedigree to the correct type of inheritance.

Answer 1

Pedigree 1 - Autosomal recessive

Pedigree 2 - Sex-linked recessive

Pedigree 3- Sex- linked dominant

Pedigree 4- Autosomal Dominant.

Step-by-step explanation:

Pedigree 1 shows Autosomal recessive inheritance because: (refer attachment)

• Disease is not present in parents and only in one child
• Parents are heterozygous for autosomal trait. hence their genotype is Aa.
• Absence of trait in heterozygous individual shows that it is a recessive trait.

Pedigree 2 shows Sex- linked recessive disorder because:

• The disease appears almost always in males.
• in the second generation the daughter is effected but her husband is not.
• But again their daughters are unaffected while all sons are affected.

Pedigree 3 shows Sex link dominant inheritance because:

• Affected female transmitted the disease to her son.
• Effected father has all effected daughter.

Pedigree 4 shows Autosomal dominant inheritance because:

• Each affected individual has an affected parents.
• Since both parents have the disease and their daughter does not this shows that the parents are heterozygous for the trait and the trait is Dominant.

[ Refer to the attatchment ]