#4.4.1
Genetic diversity as the number of different alleles of genes in a population.
#4.4.2
Genetic diversity is a factor enabling natural selection to occur.
#4.4.3
The principles of natural selection in the evolution of populations.
- Random mutation can result in new alleles of a gene.
- Many mutations are harmful but, in certain environments, the new allele of a gene might benefit its possessor, leading to increased reproductive success.
- The advantageous allele is inherited by members of the next generation.
- As a result, over many generations, the new allele increases in frequency in the population.
#4.4.4
Directional selection, exemplified by antibiotic resistance in bacteria, and stabilising selection, exemplified by human birth weights.
#4.4.5
Natural selection results in species that are better adapted to their environment. These adaptations may be anatomical, physiological or behavioural.
#4.4.6
Students should be able to:
- use unfamiliar information to explain how selection produces changes within a population of a species
- interpret data relating to the effect of selection in producing change within populations
- show understanding that adaptation and selection are major factors in evolution and contribute to the diversity of living organisms.
#4.4P6
Required practical 6
Use of aseptic techniques to investigate the effect of antimicrobial substances on microbial growth.