Casey has failed the past two chemistry exams and knows he is not doing well in class. he wonders how he will ever become a doctor if he cannot pass chemistry. he has not slept well lately and is beginning to feel overwhelmed. what might occur if casey does not take action at this time?

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.