Question

What is the mode of inheritance?

Answer 1

Mode of inheritance:

1. The way or manner in which a trait or even a disease is passed down from one generation to the next generation is referred to as a mode of inheritance.
2. Some common modes of inheritance are autosomal dominant, autosomal recessive, X-linked dominant, X-linked recessive, and mitochondrial inheritance.

Common modes of inheritance:

1. Autosomal dominant: This term refers to genetic conditions that occur when a mutation is found in just one copy of a gene (provided the person is heterozygous). An example of an autosomal dominant condition is hereditary breast cancer syndrome which is linked to pathogenic mutations of BRCA1, BRCA2, and PALB2.
2. Autosomal recessive: It refers to a condition when the mutation is present in both copies of a gene. The person is homozygous for the mutation in this case. Cystic fibrosis and sickle cell anemia are two examples of autosomal recessive conditions.
3. X-linked dominant: This term refers to genetic disorders that are only associated with mutations on the X chromosome. In females (two X chromosomes) and males (one X chromosome), a single copy of a mutation is enough to induce diseases (one X chromosome).In some cases, the absence of a functioning gene can result in male mortality.
4. X-linked recessive: It is linked to mutations on the X-chromosome. A female with a gene mutation who also has a normal gene in another X chromosome is usually unaffected. However, if a male carrying a mutation has only one X-chromosome then, he is affected.
5. Mitochondrial inheritance: Mitochondria have their own genetic material apart from that found in the nucleus. Mitochondria and mitochondrial DNA are passed down from one generation to the next.