Genetic diversity and adaption Flashcards
1
Q
what is the gene loci
A
physical position of a gene on a chromosome
2
Q
describe homologous chromosomes
A
- 2 chromosomes that possess the same gene loci
- may not possess the same alleles
- located in diploid (2n) cells
- one paternally derived male gamete, the other a maternally derived female gamete
3
Q
describe alleles
A
- different versions of the same type of gene
- possess a different nucleotide base sequence which may alter the polypeptide the gene encodes for
4
Q
describe gene mutation
A
- any change to the quantity of bases or base sequence in the DNA
- results in a change of the amino acid sequence of a polypeptide, altering its tertiary structure and its function
- can arise spontaneously during DNA replication
5
Q
what are the two forms of gene mutations
A
- base substitution
- base deletion
6
Q
describe base substitution
A
- one nucleotide replaced by a different one, changing the codon
+ can result in same amino acid as genetic code is degenerate
+ can alter a single amino acid, changing the tertiary structure/ r-group interactions of the protein
+ can result in a stop codon
7
Q
describe base deletion
A
- one nucleotide is removed
+ alters the reading frame
+ all codons/amino acids altered from this point
