The latitude of an observer on earths surface can be determined by measuring the altitude of polaris because earth has a ?

Which member of the following food chain will be least affected by ddt, a pesticide water pollutant, if bio-magnification is occurring? algae> zooplankton> crayfish> leopard frog> large mouth bass

Witch theory suggests all living things are made up of cell or cells

Hershey and chase confirmed that dna, not protein, was the genetic material. how do the results of their two experiments support this conclusion?