Simple diffusion is the process by which a substance moves across a cell membrane from an area of high concentration to an area of low concentration. Substances that move by simple diffusion are able to diffuse directly across the phospholipid bilayer of the cell membrane. These substances are generally small and neutral, as large or charged particles cannot cross the phospholipid bilayer. Some examples of molecules that move by simple diffusion are carbon dioxide and oxygen.
Facilitated diffusion is the process by which a substance moves across a cell membrane from an area of high concentration to an area of low concentration with the aid of a membrane protein. Substances that move by facilitated diffusion are not able to diffuse directly across the phospholipid bilayer of the cell membrane. These substances are generally large and/or charged. They therefore travel through a protein channel in the cell membrane along their concentration gradient. Some examples of substances that can move by facilitated diffusion are glucose, sodium ions and chloride ions.
The similarities between facilitated diffusion and simple diffusion are:
They both involve the movement of a substance across a cell membrane along its concentration gradient (from an area of high concentration to an area of low concentration).
They are both examples of passive transport, as neither requires energy from the cell to move the substance across the membrane.
<span>Answer: a. take place in nuclear reactors
</span><span>Controlled nuclear chain reactions are the reaction in nuclear reactors. The reaction is controlled to make its rate slower. This will make the reaction relatively safer, so the energy produced can be changed into electricity in power plant. When the reaction is not controlled, it could cause explosive like in nuclear bomb.</span>
G...eventually the larger fish would catch on that these smaller fish are a problem.
Answer:
Because it is a muscular body organ
<h2>It contains toxins</h2><h2>It killed off bird populations.</h2><h2>It caused harm to human populations.</h2>
Explanation:
Let us understand the term DDT
DDT : Dichlorodiphenyltrichloroethane
- This is a crystalline chemical compound
- Basically used for protecting insects eating crops
- It is colorless, odorless, tasteless
- Initially used as pesticides
It killed off bird populations: Though it does not kill birds directly by consuming, it has indirectly damaged the egg by making the egg's shell too thin which gets broken easily.
It controlled diseases like malaria: Since this option talks about positive attribute of DDT, this option stands invalid. This chemical compound controls mosquitoes attacking the crop.
It caused harm to human populations: DDT causes vomiting, tremors or shakiness, and seizures
It contained toxins: It contains moderate toxins.