Question

How do mutations affect traits?

Answer 1

Effect of mutations on traits:

1. The genetic makeup is responsible for an organism's genotypic traits.
2. DNA is the basic genetical information of the organism, present in our cell nuclei, and it gets is translated by cell machinery into proteins.
3. The ribosome utilizes mRNA as a reference, to generate polypeptides on the basis of the sequence of nucleotides.
4. The polypeptide is further folded into a functional protein.
5. The DNA sequence of a gene determines the amino acid sequence of the resulting protein.
6. Thus, any changes in DNA sequence can result in changes in protein function. This is called a mutation.
7. Mutations can be beneficial, bad, or neutral depending upon whether the effect of the mutation is positive, negative, or silent.
8. A change in a single nucleotide with a codon can lead to a complete frameshift producing different successive amino acids, and this is called frameshift mutation.
9. The genetic variation thus gets reflected in the physiological characteristics of the living organism.

Sickle Cell Anaemia:

1. An example of gene mutation is Sickle cell anaemia.
2. SCA is an autosomal recessive disease caused by a point mutation in the hemoglobin beta gene found on chromosome 11p15.5.
3. In this disorder, the body produces, crescent or sickle-shaped red blood cells, instead of normal globular RBCs.
4. Sickle cells typically die in 10 to 20 days, in contrast to 120 for normal RBCs.
5. This causes a shortage of red blood cells.