Answer:
Pedigree 1 - Autosomal recessive
Pedigree 2 - Sex-linked recessive
Pedigree 3- Sex- linked dominant
Pedigree 4- Autosomal Dominant.
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 ]
