Across
- 1. the genetic code that an organism has
- 7. organisms exit a population
- 9. natural selection favors the middle phenotype
- 10. organisms start new population and this alters allele frequencies
- 12. natural disaster reduces population size altering allele frequencies
- 13. survival of the fittest
- 14. change in allele frequencies over time
- 16. group of organisms in the same place that can interbreed
- 18. random changes in allele frequencies in small populations
- 19. when organisms enter or leave a population
Down
- 2. the physical traits that an organism has
- 3. organisms enter a population
- 4. ultimate source of genetic variation
- 5. natural selection favors one extreme phenotype
- 6. natural selection favors both extreme phenotypes
- 8. evolution of a new species
- 9. selecting a mate based on a particular trait
- 11. the collection of all alleles in a population
- 15. traits that are controlled by several different genes
- 17. different versions of a gene