genetic biodiversity Flashcards
what is a gene?
section of DNA which codes for a particular protein
what is an allele
different versions of the same gene
how does gene flow affect genetic diversity
- increases alleles present
- increases GB
how does genetic drift affect genetic biodiversity?
- independent assortment and crossing over
- so no guarantee that genetic alleles will pass on
- decreases GB
how do mutations affect genetic biodiversity?
- more alleles available (created)
- increases GB
how are major mutations avoided?
- code is degenerate
- so some triplets code for the same amino acid
- only 1 base is changed so this doesn’t change amino acids formed
how does artificial selection affect genetic biodiversity?
- humans breed for desired characteristics
- unwanted alleles are lost
- population is less varied
- decreased GB
how does natural selection affect genetic biodiversity?
- selective pressures
- disadvantageous alleles are less likely to be passed on
- decreases GB
how does genetic bottleneck affect genetic biodiversity?
- most of population do not survive an event
- leaves a smaller population with less alleles
- decreases GB
how does the founder effect affect genetic biodiversity?
- all alleles/gene come from same individual
- a new population is founded after separating from the main population
- decreases GB
how do rare breeds affect genetic biodiversity?
- when only a small number of individuals of a breed remain
- they are selected for specific characteristics
- decreases GB (it is already low)
what is meant by polymorphic genes?
genes with more than one allele
- increases GB
how is the proportion of polymorphic gene loci calculated?
number of polymorphic gene loci / total number of loci
what is meant by loci / locus
the position of the gene on a chromosome
