It is muscle and nerve tissue
Answer:
C.
Explanation:
Every DNA nucleotide pair will consist of one pyrimidine and one purine. Due to the chemical structures of the different bases, adenine (A) will always bind with thymine (T) and guanine (G) will bind with cytosine (C). The same is true for RNA except that A always pairs with a close relative of thymine, uracil (U).
The main responsible for the delay among the atrial and
ventricular contractions is the action potential conduction velocity of the AV
node cells. If the atria and ventricles contract simultaneously, atria cannot
give any help in filling the ventricles, which is needed, especially in those
with stiff ventricles as in the elderly. Hence atria have to contract first and
then the ventricles.
