Genetic diversity and Adaptation Flashcards
What is genetic diversity
what’s an allele
number of different alleles of genes in a population
allele is variations of a gene
process of natural selection:
types of selection:
leads to evolution of populations
new alleles of a gene are created by random mutation
new allele may be advantageous in certain environments, making them more likely to live, reproduce and have offspring
offspring inherit the advantageous gene
over many generations the new allele increases in frequency
directional selection and stabilising selection
directional v stabilising selection
directional- an extreme phenotype has the selective advantage
stabilising- the average phenotype has the selective advantage
RP6: How do you prevent contamination?
working closely to a Bunsen burner
close windows and doors
wipe surfaces with disinfectant before and after the practical
minimise opening of containers of bacteria
flame neck of any bottles used
flame inoculating loop before use
RP6: steps
1) transfer bacteria from broth to agar plate
2) evenly distribute on plate using a sterile spreader
3) place multidisc antibiotic ring onto plate using sterile forceps
4) place a lid on top and lightly tape it in place- incubate at 25 degrees for 48 hours
5) after each incubation, for each antibiotic, measure the diameter and calculate the zone of inhibition.
RP6: 1) transfer bacteria from broth to agar plate
2) evenly distribute on plate using a sterile spreader -why evenly?
3) place multidisc antibiotic ring onto plate using sterile forceps -how sterile?
4) place a lid on top and lightly tape it in place, then invert- incubate at 25 degrees for 48 hours- why 25?- why tape lightly, why invert??
5) after each incubation, for each antibiotic, measure the diameter and calculate the zone of inhibition.
2) reliable results
3) run through Bunsen burner
4) 25- prevent growth of harmful bacteria. lightly-allows oxygen entering- discourages growth of anaerobic bacteria. invert- prevent condensation falling onto the agar
