The first steps a scientist would do when starting a scientific experiment is to: question, do background research, and construct a hypothesis.
Answer: Valves in the veins
Explanation: The flow of the blood inside the body takes place through the veins and arteries. The oxygenated blood from the heart is supplied to the different parts of the body.
The blood flows from the capillaries to the venules and from there to the veins. The blood moves in the veins by the rhythmic movement of the smooth muscles in the body.
Most of the blood moves against the gravity so there is a chance that it can backflow so to prevent this there are valves in the veins known as one way valves.
The phospholipid no later regulates the amount of water that travels in and out of the cell.
Answer:
A mutation is simply an error in the copying of DNA it generally does not have major effects. Mutations are changes in the DNA sequence.
Tumors form by an uncontrolled error in a stage of mitosis that continue to generate cells that aren't correct and eventually lead to tumors.
Explanation:
The answer is A.) carbon dioxide, water, oxygen, nitrogen, and hydrogen
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