<span>Controlled variable is a variable that was made constant in the research. That was because the controlled variables can influence the dependent or independent variable. If the variables is not made constant, it can alter the research result and made it invalid.
In this case, </span>the caffeine and alcohol intake might alter the physical activity or the blood glucose so it should be controlled.
Clown fish and sea anemones.
Answer:
O blood is a recessive trait, so none of the children will have O blood. The genes for either type A or Type B will be determined by the egg/sperm being fertilized with the reproductive cell of the other parent. the probability of receiving either of the gene versions is 1/2, so half of the children will have A blood and the other half will have B blood