Answer:
b
Explanation:
The pulmonary circulation is a division of the circulatory system in all vertebrates. The circuit begins with deoxygenated blood returned from the body to the right atrium of the heart where it is pumped out from the right ventricle to the lungs.
Answer:
Mitochondria
Explanation:
<em>The mitochondrion is a relatively small, double membrane organelle that primarily serves as the site of oxidative phosphorylation; a process that generates energy in the form of ATP for the running of cell's activities.</em>
Hence, a cell that requires a lot of energy might need a large number of mitochondria in order to meet the energy demand of the cell.
The answer is mitochondria.
Atoms are electrically neutral because they have equal numbers of protons positively charged and electrons negatively charged.
Answer:
Explanation:
Proto-oncogenes are genes that have the potential to turn normal cells to cancer cells if they mutate. Once they have a mutation, they are called oncogenes. These typically code for proteins that control the cell cycle and cell growth.
Ras proteins are intracellular, and act as molecular switches that can be inactive or active. If they are inactive and receive a signal from the extracellular space indicating that the cell has to grow, they bind GTP and become activated. Once active, they send further signals that stimulate cell proliferation and division. After a while of sending those signals, the Ras protein hydrolizes GTP to GDP because it has an intrinsic GTPase activity, and becomes inactive once again, stopping the growth signal.
Mutations in the Ras oncogene typically affect the GTPase activity, causing its loss of function and subsequently that the Ras protein stays permanently active. This, in turn, causes uncontrollable cell proliferation, characteristic of cancer.
Answer:
The answer is False.
Explanation:
Only electrons take part in the "chemical reaction". But if you collide two particles at the speed of light or close to it, then protons, neutrons and in fact other subatomic particles also take part in the reaction.