Explain how dna replication differs in prokaryotic and eukaryotic cells?

Which of the following requires the use of energy and the of transport proteins to move a molecule across a cell membrane?

Ascientist is investigating the effects of salinity on fish development. he places fertilized fish eggs in an aquarium that contains low salinity and observes their development. what factor would improve experimental design the most? place the fish eggs in the open ocean because that is the natural habitat include another aquarium that has normal salinity to compare to the low salinity aquarium include an aquarium that replaces salt with sugar to confirm that the effects are specific to salt grow algae with the fish eggs in order to provide adequate nutrients to the developing embryos

The backbone of the double helix has an alternating molecules. what do you call these alternating molecule?