Suppose your research population was located in small groups in numerous remote locations. You could identify all groups and then randomly select which groups you would investigate. This technique describes

Whereas dopamine stimulates sexual activity, the neurotransmitter ____ inhibits it, in part by blocking dopamine release

a. testosterone b. estrogen c. serotonin d. estradiol

Whether the zygote will develop into a male or female is determined at the moment of ____

a. gestation c. mitosis b. conception d. meiosis