Evolution and natural selection

13. the production of new organisms by the combination of genetic information of two individuals of different sexes
14. one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
15. a nucleus enclosed within the nuclear membrane and form large and complex organisms
16. the process by which individuals compete for access to mates and fertilization opportunities
17. the reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population
18. Provides important evidence for evolution and the adaptation of plants and animals to their environments throughout time
19. the dying out of a species
20. how a new kind of plant or animal species is created

1. small single-celled organisms
2. organism adapts to its environment through selectively reproducing changes in its genotype
3. extreme example of genetic drift that happens when the size of a population is severely reduced
4. the biological mechanism by which organisms adjust to new environments or to changes in their current environment
5. asexual reproduction by a separation of the body into two new bodies
6. provides the raw material for natural selection and thus is a key focus of evolutionary theory
7. the reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population
8. the change in frequency of an existing gene variant in the population due to random chance
9. a mode of reproduction in which a new offspring is produced by a single parent
10. provides a record of how creatures evolved and how this process can be represented by a 'tree of life', showing that all species are related to each other
11. variations the diversity in a particular characteristic among individuals within a population
12. any movement of individuals, and/or the genetic material they carry, from one population to another