Answer:B). Cell membranes are composed of a lipid bilayer.
Explanation: A membrane is a lipid bilayer that surrounds the cell. Lipids have two parts: the fatty acid chain (the tail) and the phosphate group (the head).
The phosphate head groups are polar, face outward and interact with the outside environment of the cell. The fatty acid chain is hydrophobic and nonpolar, face each other in the bilayer thus forming a hydrophobic fluid interior.
The hydrophobic nature of the bilayer interior makes the membrane to permit only nonpolar and hydrophobic molecules to pass through the cell membrane. This is the reason the membrane allows only molecules that dissolve in the lipid bilayer to pass through to enter or leave the cell.
Depending on what resources you use, it can be easy or difficult to get examples of each categories
Some easy way can include searching google, wikipedia, encyclopedia.org, etc. These usually give you a broad and large amount of information that you can draw out of, and an over view that allows you to know what the paragraph would be talking about before you use it.
Difficult ways would be searching through specific websites, such as national geographics, etc, which gives you specific details on the idea (and is more trusted then the others)
Remember too always get facts, not opinions, unless your question asks for others opinions, and to look for what researchers or well-known people within that topic says, and to not get any information from "who-knows-who-typed-it" websites, such as ask.com, etc.
hope this helps
Answer:
The correct option is B. The claim is invalid because there are many types of bacteria that help organisms maintain homeostasis.
Explanation:
Bacteria are often considered to be disease or infection-causing organisms but this is not true. Not all bacteria are harmful, many other bacteria's play essential roles in the maintenance of life on the Earth. The human body is made of many bacteria which help in maintaining the homeostasis of the body. The human body is surrounded by enormous bacteria that are good and they are termed as human's natural microbiota.
I think it might be Stratosphere, if Ozone layer is an option I will suggest that too.
