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.
Answer: 1
Explanation:
It is a single cell called eukaryotic cell, which doesn't have a cell wall unlike plant's which do.
Answer:
largest of the three, positive charge, inside nucleus
Explanation:
I would say A.
B and C can be eliminated because they have to do with using resources more efficiently. Now we're down to A and D, and of the two, I'd say A is most plausible. Globalization is the connection of the world with each other. With all this technology, companies see endless possibilities to sell their products. They use more and more natural resources, which can deplete those resources quickly.
4,000 species can be found around the world
