Question

1.describe in detail, the organization of the mitochondrial genome and the nuclear genome and how mutation in either can result in disease?

2. Discuss in detail different types of chromosomal rearrangements and give examples lf how these may result inva syndrome, diseasr or disorder?

Answer 1

1. The human mitochondrial genome is double-stranded and circularly organised. Mutation of mtDNA will result in anemia, dementia, neurological disorders that are passed only down the generation.This works in a similar mechanism as that of X-linked.

The nuclear genome organisation involves compact packing of highly complex double stranded DNA around histone octomer. Mutation of nuclear DNA will result in autosomal diseases and X linked inheritance such as sickle cell anemia, cyclic fibrosis, night blindness and so on.

2.duplication of chromosomal regions will increase the copy number of the genes resulting in corresponding quantity of protein production. If the repeated copies are short and adjacent to the original sequence, it is known as short tandem repeats. If they are long and at a distance, they are called transposed segments.

Deletion of chromosome may it may not involve centromere. When centromere is deleted( acentric), such deletion will be lost in cell cycle. Deletions without centromere will if5en alter the gene dosage and result in altered phenotype.

Chromosomal rearrangements	example	disease/disorder/ syndrome
Deletion of DNA segments	cri-du-chat	syndrome
Duplication of DNA segments	charcoal Marie tooth disease type 1	disease