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. :)
Answer:
40%
Explanation:
Remember that guanine always pairs with cytosine, and thymine always pairs with adenine. That means that any time there is a guanine, there is always a cytosine.
If there are 10% guanines, then there are 10% cytosines. That means the total of guanines and cytosines is 20%.
The other 2 bases (thymine and adenine) have to make up the rest of the bases. That means they have to make up 100-20 = 80%.
Again, there will be equal amounts of thymine and adenine, so 80%/2 = 40%.
Fossils are physical evidence of preexisting organisms, either plant or animal. ... Fossils of any kind are useful in "reading the rock record," meaning they help us decipher the history of the earth. They can help us determine the geologic age and environment (the paleoenvironment) in which they were deposited.
A hypothesis is classified as an ¨If, Then¨ statement. Example: If I punch a brick, then it will hurt.
