Answer:
B. Theory
Explanation:
A theory can be changed as new information is discovered.
Brain size has increased nearly 3x in 4 million years.
Cancer cells reproduce the same way the other cells reproduce. The difference between cancer cells and others is that their reproduction is uncontrollable. They constantly go through the cell cycle and they reproduce. Two ways cell reproductions are meiosis and mitosis. DNA duplicates itself. Cancer is incessantly receiving messages.
Answer: Ligand gated channel
Explanation:
Ligand gated channel is an essential membrane protein that has pores and allows the passage of specific ions across the plasma membrane when it is activated by a specific chemical . Examples of such ions that pass through Ligand gated channels are Sodium ions, Potassium ions, Calcium ions. Ligand gated channels are found in extensions of the nerve cells.
The answer to this is protein.
Hydrochloric acid in digestive system is found in stomach, which is the only main digestive organ with an acidic pH 2.
In the stomach, only one kind of the primary food substance is chemically digested, which is protein. It is digested with the help of enzyme Pepsin, which breaks protein chains into polypeptides.
After that, the other organs of the digestive system has more of a neutral to slightly alkali condition, which is not related to hcl. Therefore, the answer is protein.