9 - Genetic diversity Flashcards
mutations, meiosis and genetic variation, genetic diversity and adaptation, types of selection (18 cards)
centromere
constricted area of the chromosome where sister chromatids are held together
sister chromatids
a replicate of a chromosome
homologous chromosomes
- chromosomes pairs/ two sister chromatids
- homologous for gene, different for the allele
chromosome mutation
mutation that changes the structure of a chromosome
point mutation
one base pair is replaced by another
nonsense (NOT the song by sabrina carpenter)
mutation that results in an amino acid being replaced by a stop signal
gamete mutation
mutation associated with meiosis
insertion mutation
nucleotide pair inserted
deletion mutation
nucleotide pair deleted
frameshift
whole sequence of amino acids changed after mutation
missense
mutation results in one amino acid being replaced by another
somatic mutation
mutation associated with mitosis
mutagen
substance that causes mutation (eg. gamma ray for good old bruce)
polyploidy
when organisms have three or more sets of chromosomes (rather than 2)
non-disjuntion
changes in numbers of individual chromosome (gametes having either one more or one less chromosome)
silent mutation
mutation to a genes DNA sequence that have no effect on the amino acid sequence coded for by that gene
importance of meiosis in sexual reproduction
- produces genetically different gametes
- THAT ARE haploid cells
- (SO…) fertilisation maintains the diploid number (from gen one to next gen)
- (AND…) introduces genetic variation
what processes result in genetic variation?
- crossing over
- mutation
- fertilisation (RANDOM fusion of gametes)
- independent assortment
