meiosis and variation Flashcards
what are genetic mutations?
changes in the base sequence of chromosomes.
what are mutagenic agents?
factor that increases the rate of mutations.
what is a gene?
a sequence of DNA that codes for a polypeptide
what is an allele
gene with a ddifferent base sequence
what do all alleles arise from?
mutations
what does it mean by degenerate?
mutiple triplets code for the same amino acid.
what is meant by over-lapping?
a base can only be read as part of a triplet.
what happens when the amino acid changes?
protein is modified
alter hydrogen and ionic bonds in different places.
results to non functioning protein.
what are examples of mutagenic agents
carcinogens
radiations-gamma and beta
what can things in carcinogens do?
they alter the structure of DNA
interfere with transcription.
