4.5 Genetic Diversity and Adaptation Flashcards
1
Q
What does genetic diversity allow to occur?
A
Natural selection
2
Q
What are the two types of natural selection?
A
- Directional
- Stabilising
3
Q
What are the principles of natural selection in the evolution of populations?
A
- There is existing variation within the population
- Mutation occurs
- Some organisms have a specific allele that helps them survive
- Organisms with **advantageous allele reproduce
- Increased frequency of advantageous allele, decrease frequency of non-advantageous allele
- OVER MANY GENERATIONS new allele frequency in the population
4
Q
What is an example of directional selection?
A
Antibiotic resistance
5
Q
What is directional selection?
A
- when phenotypes of one extreme are selected for and the other extreme selected against
- pushes curve to the right
- occurs when there is a change in environment
6
Q
What is stabilising selection?
A
- acts against both extremes individuals closer to the mean are favoured
-
narrower spread
(e.g birth weights)
7
Q
What are the three types of adaptation?
A
- Anatomical (structural/physical features)
- Physiological (biological processes within the organism)
- Behavioural (mannerisms and the way the organism acts)
8
Q
What are some aseptic techniques?
A
- washing hands thoroughly
- disinfecting work surfaces
- sterilising apparatus by flaming
- having a lit blue bunsen burner to sterilise the air
- wearing gloves
9
Q
natural selection definition
A
- fitter individuals who are better adapted to the environment survive and pass on advantageous genes to future generations.
10
Q
how does evolution come about?
A
- natural selection leads to evolution
-frequency of alleles in gene pool changes overtime as a result of natural selection
11
Q
example of directional selection
A
- antibiotic resistance
- over many generations will see a shift as far more bacteria have the extreme trait (antibiotic resistance) so shift in allele frequency
