Biology

4. the diversification of a group of organisms
6. a type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value
8. variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance
10. the introduction of genetic material from one population of a species to another
14. an animal establishes a home in a habitat because it has resources it can utilize or because the habitat is ideal for them.
18. when individuals of the intermediate phenotype are less fit than those of both higher and lower phenotype
19. The complete set of DNA in an organism
20. the process whereby organisms better adapted to their environment tend to survive and produce more offspring

1. the inability of a species to breed successfully with related species due to geographical, behavioral, physiological, or genetic barriers or differences.
2. occurs when two populations are separated by geographic barriers such as rivers, mountains, or bodies of water.
3. an area that contains a chain or group of islands scattered in lakes, rivers, or the ocean.
5. occurs when phenotypes at both extremes of the phenotypic distribution are selected against.
7. the stock of different genes in an interbreeding population.
9. The condition where a gene pool is not changing in frequency across generations
11. the complete disappearance of a species from Earth
12. how common an allele is in a population
13. a type of reproductive isolation mechanism among sexual organisms
15. an animal leaves its home because the habitat is no longer ideal for them and they need to find a more suitable environment
16. one of two or more alternative forms of a gene that arise from mutation
17. still in existence