most of a atoms mass is in the nucleus of the atom:) hope this helps you
Answer:
Veins
1l carry blood from tissue of the body to the heart
2) are usually found closer beneath the skin
3) are less muscular then arteries
4) collapse if blood flow stops
arteries
1) carry blood back away from the heart to the tissue of the body.
2) found deeper within the body
3) are more muscular then veins
4) would generally remain open even if blood stops because of it's muscular structure.
Answer:
C .they take up the usable forms of nitrogen found in the soil .
Explanation:
Answer;
Cell membrane
A cell membrane acts as a boundary that separates things that are inside the system from those that are outside the system.
Explanation;
It is a thin semipermeable structure that surrounds the cytoplasm of a cell.
The membrane functions to protect the integrity of the internal environment of the cell by allowing selective movements of materials in and out of the cell.
The membrane consists of a phospholipid bilayer with proteins embedded in it.
The spinal cord is the primary means for transmitting messages between the brain and the rest of the body.
