What blood types are possible for a child whose parents both have ab blood type?

Alaska and northern canada have a diet rich in vitamin d and their skin color is darker than predicted on the basis of iv intensity at their latitude. explain the observation:

What happened to rosalind franklin in 1956?

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