Elizabeth is testing the effects of soil additives on fruit production at an apple orchard. elizabeth would like to find out if the soil additives increase the mass of the apples. what tool will elizabeth need in order to complete her research?

Which statements are true of a scientific theory but not a hypothesis

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?

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.