The ability of a muscle to contract and relax is dependent on the flow of what substance in and out of the muscle cell?

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution

What tool do geneticists use to predict the outcome of genetic crosses? a.karyotype b.punnett square c.centrifuge

The source of energy shown in the image is (renewable, non renewable, polluting) a drawback of building a dam is that (it will destroy ecosystems, it requires fossil fuels, it won’t be useful for irrigation)