Across
- 5. the expression of a particular trait in an organism
- 6. the set of genes in an organism
- 9. ___________ twins who come from two different eggs fertilized by two different sperm
- 10. descended from ancestors with similar genetics
- 11. a chemical communication system, using hormones, by which messages are sent through the bloodstream
Down
- 1. the center of control of the endocrine system that secretes a large number of hormones
- 2. the basic building blocks of heredity
- 3. chemical substances that carry messages through the body in blood
- 4. __________ twins who come from one fertilized egg; twins having the same heredity.
- 7. descended from ancestors with dissimilar genetics
- 8. the genetic transmission of characteristics from parents to their offspring