Genetics, Populations, Evolution and Ecosystems: Evolution May Lead to Speciation - Variation & Speciation Flashcards
1
Q
What factors affect variation in a phenotype?
A
- Genetic factors
- Environmental factors
2
Q
Define genetic variation
A
- Differences in genotypes caused by different alleles
3
Q
What is the primary cause of genetic variation?
A
- Mutation
4
Q
In what other processes is genetic variation introduced other than through mutation?
A
- Meiosis
- Random fertilisation of gametes
5
Q
How does meiosis introduce genetic variation?
A
- Crossing over of non-sister chromatids creates new combinations of alleles
- Independent segregation of chromosomes creates different combinations of chromosomes
6
Q
Define selection pressure
A
- Pressures that affect an organism’s likelihood of surviving
- E.g predation, disease and competition
7
Q
Define evolution
A
- Change in allele frequencies in a population
