Answer:
True
Explanation:
The plasma membrane does not allow the charged and polar substances to cross through its inner core that is made up of non-polar fatty acid tails of the phospholipids. Therefore, membrane proteins serve as transport proteins. Some of the transport proteins allow the movement of substances down the concentration gradient without any energy input. This passive movement of substances via membrane transport proteins is called facilitated diffusion.
Carriers and channels are the membrane proteins that facilitate the diffusion of substances. Carrier proteins pick the substances from one side of the membrane and undergo a change in shape to deliver the substance on the other side. Channel proteins make a passage for the movement of substances. Examples: aquaporins, ion channels.
Phenotype is an organism's genetic makeup behind the scenes.
<span>An element is a substance that cannot be broken into other substances further.An element is composed of one type of atoms all over. Like a molecule can be divided into atoms further. For example, Water is a molecule which is made up of Oxygen (O), Hydrogen (H). Here, Oxygen and Hydrogen are elements and cannot be further broken down into other substances.</span><span />
B. essential
We cannot store up amino acids on our body, but we can have amino acids through consumption of food. These amino acids of which the body cannot make is called as essential amino acids.