Genes and mutation Flashcards
A gene is a part of…
DNA molecule, where the nucleotide sequence codes for just one polypeptide.
One DNA molecule contains many…
genes.
Mutation is a change in…
the nucleotide sequence of a gene and it may result in an altered polypeptide.
Most of the genes have…
different variants called alleles, which came from the process of mutation.
All the chemical activities in the cell are controlled by…
enzymes.
Since DNA is a code for…
proteins, it controls which enzymes are made and therefore it controls the cell’s activity.
The triplet code- the sequence of…
nucleotide bases in a DNA molecule is a code for the sequence of amino acids in a polypeptide.
Each sequence of three…
bases stand for one amino acid.
The triplet code is always read in one…
direction and from only one of the two DNA strands. (the sense strand)
A base substitution is a replacement in…
a single nucleotide, which may result in a mutation.
Sickle cell anaemia is caused by…
substitution
In allele of the gene causing sickle cell anaemia, one…
amino acid is replaced by another. Therefore the beta polypeptide for haemoglobin is not synthesised properly.
