14. Surface Area , and Volume Area limits the size of cells.
15 .A cell is a metabolic compartment where a multitude of chemical reactions occur. The number of reactions increase as the volume of metabolic volume within a cell increases. (The larger the volume the larger the number of reactions)
All raw materials necessary for metabolism can enter the cell only through its cell membrane.
The greater the surface area the larger the amount of raw materials that can enter at only one time.
Each unit of volume requires a specific amount of surface area to supply its metabolism with raw materials. The amount of surface area available to each unit of volume varies with the size of a cell.
As a cell grows its SA/V decreases.
At some point in its growth its SA/V becomes so small that its surface area is too small to supply its raw materials to its volume. At this point the cell cannot get larger.
16. Cells only divide when they receive specific signals from proteins called mitogens,the presence of mitogens can limit cell division. Mitogens are needed for cell division in healthy cells and are released depending on what cells the body needs.
In a direct democracy, power is inherited rather than allocated through elections.
Answer: Option A
<u>Explanation:</u>
Direct democracy means where the citizens can participate in making decisions. Here citizens possess the right to vote against issues instead of a candidate or party. Here everyone has the right to take decisions. It’s a participatory kind of democracy where the decisions are affected by the people.
If a group is affected because of an issue they can directly apply for a recall. Here the direct interaction of people plays a vital role. In most countries this direct democracy is not in practice as it was outsmarted by bunch of elites who wanted to monopolize power.
Answer:
d. Preload increases.
Explanation:
Preload is affected by the rate of venous return and the venous blood pressure , which are affected by the volume of circulating blood and venous tone .
The preload is related to ventricular end - diastolic volume ,
The higher end - diastolic volume have a higher preload .
<u>Preload is approximated via echocardiographic measurement end diastolic volume or EDV.
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Preload is increased by exercising , or increase in blood pressure and neuroendocrine excitement .
Answer:
Bacteria and other microbes play an important role in the environment that is of decomposers which act in the last stage of the food chain. These microorganisms like bacteria cause the breakdown of energy-rich organic compounds. These compounds come from decaying matter of plants such as leaves or animals waste products and dead bodies.