Human Genetics and Disorders

Mutations in the MEFV gene, which encode the inflammatory regulator pyrin, are associated with familial Mediterranean fever.

Mutations occur in the Bruton's tyrosine kinase (Btk) gene.

The spontaneous creation of alternative pathway C3 convertase on the red cell is normally eliminated through membrane bound DAF.

In particular, the receptor for IL-7 is the most crucial for lymphocyte differentiation.

Lack of CD154 (CD40L) prevents signalling to the B-cell CD40 to bring about Ig class-switching away from IgM.

The N370S mutation is associated with Gaucher disease type 1.

Thymidine dimers are a pair of abnormally chemically-bonded adjacent thymine bases in DNA, resulting from damage by ultraviolet irradiation.

In missense mutation, the new nucleotide alters the codon so as to produce an altered amino acid in the polypeptide chain.

Stem cells are unable to differentiate from mature T-cells in the absence of thymic microenvironment.

This is the correct answer as a muscular body is an acquired trait and cannot be inherited.

Leukocyte Adhesion deficency is a myeloid lineage defect.

Sickle cell anaemia is a genetic disorder caused due to fault in haemoglobin protein expression.

Here, in beta globin chain of haemoglobin, glutamate is changed into valine.

This is the correct answer. Thalassemia is a form of inherited autosomal recessive blood disorder characterised by abnormal formation of haemoglobin. Cystic fibrosis is an autosomal recessive genetic disorder characterised by the buildup of thick, sticky mucus that can damage many of the body's organs.

Pleiotropy occurs when one gene influences multiple, seemingly unrelated phenotypic traits. Consequently, a mutation in a pleiotropic gene may have an effect on some or all traits simultaneously. Well known examples of pleiotropy include phenylketonuria, albinism and sickle-cell anaemia.