<span>The correct answer is membrane. Just like the fence protects the yard so does a membrane protect the cell. It prevents things from getting in or out unless passageways are created. The things in the yard would be the mitochondria and other organelles, while the air in the yard and the ground where all things are found would be the cytoplasm. The membrane protects what's in just like a fence protects those in the yard.</span>
Plasma protein status. Albumin, globulins and fibrinogen are the major plasma proteins.
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.
If they are negative and positive then they are attraction if the are the same then they are repulsion.
Hope this helps. Have a nice day.
