Biology Review

2. having different alleles for a gene
4. type of symbiotic relationship in which both organisms involved benefit
8. having a lower concentration of solute than another solution
9. phylogenetic tree constructed from a series of two-way branch points, suggesting ancestral relationships among species
11. point at which the number of diffusing molecules moving in one direction is equal to the number moving in the opposite direction
12. part of a cell with a specific function
14. movement particles of a substance from where they are more concentrated to where they are less concentrated
15. contribution that an individual makes to the gene pool of the next generation compared to the contributions of other individuals
16. observable traits of an organism
17. having a higher concentration of solute than another solution
19. cell with a nucleus (surrounded by its own membrane) and other internal organelles

1. complete set of an organism's genetic material
3. cell lacking a nucleus and most other organelles
5. nonliving physical or chemical condition in an environment
6. formation of new species
7. difference among members of a species
10. descriptive of an allele in a heterozygous individual that does not appear to affect a trait
13. generation-to-generation change in the proportion of different inherited genes in a population that account for all of the changes that have transformed life over an immense time
17. having identical alleles for a gene
18. passive transport of water across a selectively permeable membrane