Some atoms of an element contain more neutrons or fewer neutrons than the most commonly found "version" of the atoms for that element. These "alternate versions" of the standard atom are called:

What must happen before meiosis can begin? a. four gametes must be produced b. the four tetrads must be pulled apart c. dna doubles and produces sister chromatids d. the cell membrane pinches together

The model illustrates a process by which a substance is taken up by a cell

The reactions that occur in the ribosome, where amino acids are combined to form proteins are anabolic or catabolic?