Question

Study the given pedigree chart in which neither of the parents shows the trait but the trait is present in both male and female children.

Give one example of such a trait in human beings.

Hint:

In autosomal recessive inheritance, both parents must be carriers of the recessive allele for the trait to be expressed in the offspring. Affected individuals inherit one recessive allele from each parent.

Answer 1

Example of a Recessive Trait in Humans 

Observation: The given pedigree chart shows that neither of the parents expresses the trait, but both male and female children exhibit it. This pattern suggests the inheritance of a **recessive trait**.

Example of such a trait in humans:

An example of a recessive trait that follows this pattern is **cystic fibrosis**.

• Cystic fibrosis is caused by a mutation in the CFTR gene, which leads to the production of thick mucus in the lungs and digestive system.
• The condition is inherited in a recessive manner, meaning both parents must be carriers (heterozygous) for the child to inherit the disease.
• Even though neither parent shows symptoms, they can pass on the mutated gene to their offspring, who can then express the trait if they inherit the mutated gene from both parents.