chapter 17 and 18 hon bio
Across
- 4. formation of a new species
- 5. form of natural selection when individuals at one end of a distribution curve have fitness then individuals in the middle or at the other end of the curve
- 7. structures that are similar in different species of different ancestry
- 8. natural selection in which individuals at the upper and lower ends of the curve have higher fitness then individuals near the middle of the curve
- 11. structure that is inherited from ancestrs but has lost much or all of it’s original function
- 13. the number of times an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene
- 14. change overtime the process by which modern orgnisms have descended from ancient organisms fossil preserved remains or traces of ancient organisms
- 18. a change an allele frequency following a dramatic reduction in the size of a population
- 21. the study of past ans present distribution of organisms
- 24. the movement of genes into or out of a population
- 25. process by which organisms that are most suited to their environment survive and reproduce most successfully, also called survival of the fittest
- 26. trait controlled by one gene that had 2 alleles
- 27. form of reproductive isolation in which 2 populations are separated bt geographic barriers such as rivers, mountains, or bodies of water, leading ot the formation of 2 separate subspecies
- 28. heritable characteristic that increase in organisms ability to survive and reproduce in an environment
Down
- 1. change in allele frequencies as a result of the migration of a small subgroup of a population
- 2. selective breeding of plant and animals to promote the occurrence of desirable traits in offspring
- 3. body parts that share a common function, but not structure
- 6. for of reproductive isolation in which 2 or more species reproduce at different times
- 9. how well and organism can survive and reproduce in it’s environment
- 10. situation in which allele frequencies in a population remain the same
- 12. principle that states that allele frequencies in a population remain constant unless one or more factors cause those frequencies to change
- 15. form of natural selection in which individuals near the center of a distribution curve have higher fitness then individuals at the other end
- 16. when individuals select mate based on heritable traits
- 17. form of reproductive isolation in which 2 populations develop differences in courtship rituals or other behaviors that prevent them from breeding
- 19. all genes, including different alleles for each gene, that are present in a population at any one time
- 20. random change in allele frequency caused by a series of chance occurance that causes an allele to become more or less common in a population
- 22. trait controlled by 2 or more genes
- 23. a group of homotic genes clustered together that determine the head to tail identity of body parts in animals. all hox genes contain the homobox DNA sequance