Answer:
What sends oxygenated blood back to the heart from the lungs?
Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.
Explanation:
<span>When cells divide uncontrollably, then there is a huge number of them and they take up most of the space in the body. Thus, lumps start to appear on and in a person's body, on organs and skin, and these lumps often represent cancer. So, uncontrollable division of cells can lead to cancer. Hope this helps. Let me know if you need additional help!</span>
A gene contains the genetic instructions for making proteins.
Robert Hooke is the first person to observe cells as microscopic structures.
He was of British descent and, fun fact, he discovered cells by looking at a sliver of cork under a microscope lens (although the 'fun fact' is heavily simplified).
Grasses because they have a shallow root system and don't take long to grow.