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.
Hydrogen bonds can form between regions of polar molecules that are <span>oppositely charged.
Source credit: </span>https://quizlet.com/16761990/biology-chapter-22-saud-flash-cards/
Noctiluca scintillans, commonly known as the sea tinkle and also published as Noctiluca miliaris, is a free-living, nonparasitic, marine-dwelling species of dinoflagellate that exhibits bioluminescence when disturbed (popularly known as mareel). Its bioluminescence is produced throughout the cytoplasm of this single-celled protist, by a luciferin-luciferase reaction in thousands of spherically shaped organelles, called scintillons. Nonluminescent populations within the genus Noctiluca lack these scintillons.
Answer:Hiking uphill.
Cycling more than 10 miles per hour or steeply uphill.
Swimming fast or lap swimming.
Dancing, fast dancing, and step aerobics.
Strength training.
Heavy gardening with digging, hoeing
Explanation:
For an activity to be vigorous, you need to work at 70 to 85 percent of your maximum heart rate, according to the American Heart Association. Examples of vigorous exercise include: running. cycling at 10 mph or faster
Answer:
A.
Explanation:
H2O is water. It has 2 hydrogen atoms and 1 oxygen atom, and that makes H2O which is water.
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