In a phylogenetic tree, what does the distance between branches represent? similarities in physical appearance

the amount of evolutionary change

the time it took for the change to occur

a shared common ancestor

In the context of the neural impulse, which of the following is true about the depolarization of neuron membranes?

Taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? view available hint(s)taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? the enzyme will not work on human dna.nothing should be altered.the ph should be decreased.the temperature should be raised.

How do the sperm cells get from the stigma to the ovules? a. they slide down the petals to the bottom of the flower. b. they travel through pollen tubes. c. they travel along filaments. d. insects carry the sperm cells from the stigma to the ovules.