According to darwin's theory of natural selection, individuals who survive are the ones best adapted for their environment. their survival is due to
a. possession of adaptations developed through use.
b. possession of inherited adaptations that maximize fitness
c. lack of competition within the species
d. choices made by plant and animal breeders

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

The pharynx is the structure in the body that serves as a pathway of both air and food. how does the body make sure that food does not get into the lungs? the salivary glands secrete enzymes that pull food out of the air pathway. the small intestine pushes the air out of the digestive system. the pancreas breaks down food in the air pathway. the epiglottis closes the air pathway so that food will not enter it.

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic