4.4 Genetic Diversity Flashcards
1
Q
Define genetic diversity
A
The number of different alleles of genes in a population
2
Q
Reasons for low levels of Genetic Diversity
A
- Small population
- Inbreeding
3
Q
Explain the process of natural selection
A
- A random mutation occurs in one cell, resulting in a new allele in a gene for XXX
- Those with allele areresistant to ZZZ
- YYY provides a selection pressure
- The cell is more likely to survive, and reproduce, passing on allele to offspring
- Over generations, the allele increases in frequency in the population
4
Q
Why is there a time lag on a graph showing resistance
A
- Initally, only one individual has the desired allele
- Indiviiduals with allele will survivie to produce more offspring
- It takes many generations for the allele to increase in frequency in the population
- Become most dominant
5
Q
What are the type of adaptations that are created by natural selection
A
- Anatomical
- Physiological
- Behavioural
6
Q
Explain stabilising selection, and give an example
A
- Intermediate phenotypes best adapted to survivie in enviroment
- As intermediate phenotypes are advantageous, they become more common
- Extreme phenotypes disappear
- Birth weight in humans
7
Q
Example of stabilising selection
A
Birth weight in humans
8
Q
Explain directional selection and give an example
A
- Extreme phenotype is best adapted to survive in enviroment
- As extreme phenotypes are advantageous, they become more common, and intermediate phenotypes disappear
- Antibiotic resistance in rats
9
Q
Example of directional selection
A
Antibiotic resistance in rats
10
Q
Describe the procedures for the use of aspetic technique
A
- Wash hands with soap and disinfect surfaces
- Flame neck of bottle
- Use sterile pipette to transfer bacteria
- Use sterile spreader to spread bacteria
- Place pipette and spreader into disinfectant after use
