Many factors determine whether genes are "turned on," including

a. Social influences

Electrical wires are generally protected by a tube of plastic. A similar insulating function is preformed in the nervous system by:

a) Dendrites b) Terminal Buds c) Glial cells d) Myelin sheath

According to research, the reason many older people are no longer involved in their community is because

a. they are not asked to take part. b. they quite often are unable to take part. c. they do not wish to be involved. d. they die.