How do Watson and Crick described the structure of DNA?

The southern colonies practiced indentured servitude and slavery because cash crops such as tobacco and sugar required many workers. the fishing and shipping industries required many workers. imprisoned debtors were brought from africa to settle the colonies. indentured servitude and slavery were not allowed in the caribbean colonies.

Aresearcher conducts a focus group to learn about attitudes towards hygiene and disease prevention. two weeks after the focus group, the researcher learns one of the subjects had a heart attack at home and was hospitalized, but made a full recovery. based on dhs regulations, the researcher report this event to the irb? no, this does not need to be reported since the subject had the heart attack when they were home, not at the focus group.no, this does not need to be reported since it is unrelated to participation in the study.no, this does not need to be reported because two weeks have passed.no, this does not need to be reported since the subject recovered.

Which statement is a good description of a model? a) models are a description of nature based only on one or two variables. b) models are testable ideas but they are not very to most people. c) models are a description of nature that predicts more accurately than real events. d) models are an approximiation of a real system that omits all but most essential variables in a system.