Across
- 1. part of evolution, traits that are more favorable stick around better
- 5. observable characteristics
- 7. animals are breeder for human purposes
Down
- 2. a species changing over a long period of time, mainly positive changes
- 3. a part of DNA
- 4. change in gene structure
- 6. a string of genes
- 8. alternative form of genes caused by mutation, found in same place on chromosome