Chapter 3: The Biology of Behavior

3. Potential / The positively charged impulse that moves down an axon.
6. Transmission / The process by which many genes interact to create a single characteristic.
7. / Small segments of DNA that contains information for producing proteins.
8. Buttons / Little knobs at the end of the axon that contains tiny sacs of neurotransmitters.
9. / Chemicals that transmit information between neurons.
12. / The cells that process and transmit information in the nervous system.
14. Transmission / The hereditary passing on of traits determined by a single gene.
16. / The extent to which a characteristic is influenced by genetics.
18. / The genetic material that makes up chromosomes, is a large coiled molecule that contains genes.
20. / The organism's observed characteristics.
21. Twins / Twins that develop from a single fertilized egg that splits into two independent cells.
23. / Deficit in the ability to speak or comprehend language.
24. / Different form of a gene.

1. Twins / Twins that develop from two different eggs fertilized by two different sperm.
2. / A coiled-up thread of DNA.
4. / All the genetic information in DNA.
5. Genes / Genes that show their effect even if there is only one allele for that trait in the pair.
8. Studies / Research into hereditary influence on twins, both identical and fraternal, who were raised apart (adopted) and who were raised together.
10. / Chemically charged particles that predominate in bodily fluids; found both inside and outside cells.
11. / Study of changes in the way genes are turned on or off without a change in the sequence of DNA.
13. / Fingerlike projections from a neuron's soma that receive incoming messages from other neurons.
15. / The entire genetic makeup of an organism.
17. Genetics / The scientific study of the role of heredity in behavior.
19. Gene / Genes that show their effects only when both alleles are the same.
22. / The cell body of the neuron.