BIOLOGY Flashcards
What is evolution?
evolution is the outcome of different processes that can change the frequency of genes in a population
what is a gene pool?
the total genetic diversity found within a population or a species.
how many genes are contributed from each individual to a gene pool?
two
What is a mutation?
A mutation is a change in the sequence of an organism’s DNA.
what do mutations result in?
Mutation to a gene will result in a new allele and therefore a change in the gene pool.
What is gene flow?
gene flow is the exchange of genes between two populations
what is natural selection?
natural selection is the process through which species adapt to the environment.
what are the conditions of natural selection?
- variation
- competition
- adaptations
- selection
What are the mechanisms for evolution?
- mutation
- gene flow
- natural selection
- sexual reproduction
- genetic drift
What is genetic drift?
Genetic drift is a change in allele frequencies in a population from generation to generation that occurs due to chance events.
Steps of natural selection?
- A population has a variation in a trait
- Differential reproduction occurs
- The trait is inherited
What are selection pressures?
are external agents which affect an organism’s ability to survive.
Types of selection pressures?
- RESOURCE AVAILABILITY - food, mates, and habitat
- ENVIRONMENTAL CONDITIONS - temperature
- BIOLOGICAL FACTORS - predators and pathogens (diseases)
What does natural selection act on?
the phenotype
What is adaptive value?
the usefulness of a trait to aid the survival of an individual at any particular time.
