The phone ringing is an example of a/an: a. extinction. b. stimulus generalization. c. stimulus discrimination. d. discriminative stimulus.

Plsss > .< compare and contrast the characteristics of flatworms rounds worms and earthworms

By going through the process of cellular respiration the cell can gain molecules of atp.

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.