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.
where a species lives is their habitat.
Here's a graph showing the stages.
Look closely at the second stage-- the death rate is low but the birth rate is high.
It's <span>
D. The death rate begins to fall, but birth rates remain high for a time.</span>
A biological community of interacting organisms and their physical environment.
Pretty sure it’s A- Chlorophyll reflects green light and absorbs other colors of light.