Why did Hershey and Chase label the viral DNA with radioactive phosphorous and not radioactive sulfur?

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

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

All organisms contribute some water to the water cycle by conducting