Question: Which of the following are appropriate units for power?
A) newton·meter
B) watt
C) H.P./sec
D) joule/sec
Answer:
Watt and Joule/sec are the appropriate units for power.
Explanation:
As per the question, the physical quantity given is power.
The power is defined as the rate of consumption of energy or the rate of doing work.
Let us consider W is the amount of work done by a body in time t .
Mathematically the power of that body is written as -
power 
The unit of work is joule and the unit of time is second.
Hence, the unit of power is joule/sec.
we know that one joule/sec. = one watt.
Hence, watt is also another unit of power. Newton-metre can not be a unit of power . It may be considered as a unit of work.
Similarly H.P/sec is also not a unit of power. Here H.P stands for horse power which is another unit of power . Hence, joule/sec. and watt are the appropriate units of power.
Answer:
"As a molecule moves through the plasma membrane it passes through <em>a hydrophilic layer of phospholipid heads then a hydrophobic layer of phospholipid tails and then another hydrophilic layer of phospholipid heads".</em>
Explanation:
Biological membranes are formed by two lipidic layers, proteins, and glucans.
Lipids characterize for being amphipathic molecules, which means that they have both a hydrophilic portion and a hydrophobic portion at the same time. These molecules have a lipidic head that corresponds to a negatively charged phosphate group, which is the polar and hydrophilic portion. They also have two lipidic tails that correspond to the hydrocarbon chains -the apolar and hydrophobic portion- of the fatty acids that esterify glycerol.
Membrane lipids are arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, while their hydrophobic tails are against each other, constituting the internal part of the membrane.
Through this lipidic bilayer, some molecules can move from one side of the cell to the other, which happens because of concentration differences. When this occurs, molecules must pass through the hydrophilic layer of phospholipid heads then through the hydrophobic layer of phospholipid tails and then again through another hydrophilic layer of phospholipid heads.
The answer to the question is D
S phase, g0, g2, g1, metaphase and prophase
