Describe how a person uses many organ systems to accomplish a simple task such as brushing his or her teeth.

The two main stages of cell division are called

According to the rna world hypothesis, rna acted as the genetic material and catalyzed reactions in ancient cells. what conclusion can you draw from this?               a.  this implies that dna and proteins aren't essential in cells today.    b.  this implies that rna can catalyze any chemical reaction that enzymes catalyze.    c.  this implies that if a cell has a problem with its dna, its rna can compensate for the damaged dna.    d.  this implies that dna and proteins evolved after rna.

Which hormones are synthesized from cholesterol? a. steroidsb. modified amino acidsc. peptidesd. glycoproteinse. all of the above