<h3>1.<u> Answer;</u></h3>
A. lipid
<h3><u>Explanation;</u></h3>
- <u><em>Lipids are among the four biomolecules, others being nucleic acids, carbohydrates, and proteins.</em></u>
- <u><em>Lipids contain hydrocarbons and make up the building blocks of structure and function in living cells. Lipids includes; fats, oils, waxes and certain vitamins.</em></u>
- <u><em>Lipid can be used for energy storage in the form of fat in animals. Additionally, lipids can be used as heat insulation as fat or adipose tissue under the skin reduces heat loss.</em></u>
<h3>2. <u>Answer;</u></h3>
B. The cell membrane contains cholesterol molecules.
<h3><u>Explanation;</u></h3>
- <em><u>The structure of the lipid bi-layer allows small, uncharged substances such as oxygen and carbon dioxide, and hydrophobic molecules such as lipids, to pass through the cell membrane, down their concentration gradient, by simple diffusion.</u></em>
- <u><em>Carbon dioxide and oxygen are molecules that can move across the lipid bi-layer without the help from membrane proteins or integral proteins. They are non-polar molecules and thus can easily pass through the hydrophobic interior of a membrane.</em></u>
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.
Cell division is the process essential for growth and repair in multi-cellular organisms.
Injury to the tissue can activate surrounding cells to undergo cell division with the help of mitogens. Mitogens are the chemical substances which help in escalating mitotic divisions in the cells.
They act by activating the signal-transduction pathway which involve mitogen-activated protein kinase (MAPK).
Other possible manner could be the loss of density which could lead to the inactivation of contact inhibition. As there is a loss of cells during the injury, it makes an empty space which could also trigger or activate surrounding cell to start cell division.
In addition, at injury site the flow of blood also increases to transport various nutrients, clotting factors, growth factors etc. These increased nutrition and growth factors also speed up the process of mitosis.
I believe it is convergent evolution
