Proteins is made up of a sequence of an amion group, a carboxyl group, a hydrogen atom and a side chain bonded to the centralcarbon atom.
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.
Dispositional traits are personality traits that remain stable and relatively unchanging from about age. They refer to the tendency of an individual to behave in stable and predicted ways. It is similar with the concept of moods. Costa and McCrae believed that personality traits remain the same by the age of 30.
I think it B. but I don't know if its correct or not.
...
I see you got this from k12 too.
