When we breathe in, oxygen enters our lungs and enters small sacs in our lungs called the alveoli. In the alveoli, the oxygen diffuses INTO the bloodstream through small blood vessels, called capillaries, that surround these alveoli. The oxygen is now in our bloodstream instead of our lungs and is used in cell respiration etc.
Oppositely, carbon dioxide is diffused FROM the bloodstream TO the alveoli, also through these capillaries. The carbon dioxide is now in the lungs instead of the bloodstream and when you breathe out, the carbon dioxide is breathed out out of your lungs.
Hope this helped, even if it helped a tiny bit. :)
A=T= 40%....so together this is 80% of the DNA.
That leaves 20% to be C+G...so each is 10%. A is the answer.
B. Absolute dating uses the half-life of an element
Absolute dating is a technique that uses radioactive minerals present in rocks and fossils while relative dating compare the sample in terms of age difference. However, absolute dating is more accurate because it uses half-life of an element and provides dates in years.
Answer:
They are also keystone species, playing an important role in maintaining the biodiversity of the ecosystems in which they live. During the dry season, elephants use their tusks to dig for water. ... Wherever they live, elephants leave dung that is full of seeds from the many plants they eat.
Explanation:
