Answer:c
Explanation:sorry if this wrong don’t trust me!
Unlike arteries, veins contain valves that ensure blood flows in only one direction. (Arteries don't require valves because pressure from the heart is so strong that blood is only able to flow in one direction.) Valves also help blood travel back to the heart against the force of gravity.
<u>Answer:</u>
Great amounts of energy are released in the core of a star as lighter elements combine and form heavier elements during the process of nuclear fusion.
<u>Explanation:</u>
- Nuclear fusion is the defined as the fusion or combination of many lighter elements to form heavier element.
- Example: Two hydrogen nuclei combine or fuse to form a helium. The greatest amount of energy in star is its hydrogen which gets exhausted consequently resulting in burning of helium and forming heavier elements.
Explanation:
unicellular organism are single celled organisms and usually cab not be seen by our naked eyes. Example:yeast, microscopic algae, bacteria and more
multicellular organisms are organisms that have two or more cells. Example plants, animals
Answer:
Peripheral vascular resistance (systemic vascular resistance, SVR) is the resistance in the circulatory system that is used to create blood pressure, the flow of blood and is also a component of cardiac function. When blood vessels constrict (vasoconstriction) this leads to an increase in SVR.
The relationship between BP and viscosity is such that, given a constant systolic BP, if blood viscosity increases, then the total peripheral resistance (TPR) will necessarily increase, thereby reducing blood flow. Conversely, when viscosity decreases, blood flow and perfusion will increase.