a student conducts an experience in which she drops objects ,each with a different mass, all from the same height. she uses a stopwatch and records the time it takes for each object to hit the ground. which of the following is the independent (test) variable in her experiment?

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food

In sheep, the allele for belly fur (a) is dominant to the allele for no belly fur (a). a mother with the genotype aa and a father with the genotype aa produce an offspring.