In an experiment to test a new drug’s effectiveness, one group is given a larger dosage than is typically prescribed, and a second group is given a smaller dosage than is typically prescribed. Then, the results of the groups are compared to each other. What is missing that would improve this scientific design? a control group
a second independent variable
a dependent variable
an independent variable

What is the next step in muscle contraction after the actin changes shape? (apex)

Cold case files recently began re-investigating an old murder case. the murder took place in the park; a young man, james, was hit over the head with a brick and killed. police suspected the jealous former boyfriend of james' wife, karen. whoever killed james may have washed their hands in a near-by bird bath as detectives found blood in the bird bath. since the murder took place before dna fingerprinting was available, the suspected killer, ronnie, went free. detectives are now reviewing the blood evidence using dna fingerprinting. based on the dna fingerprints of all possible suspects, who is james' killer?

What is the ecological role of food chains and food webs