Neither of these are minerals, B.
Its not A because, they are not natural materials but instead made up of natural materials, like a rubber tree.
Its not C because, like I said, plastic is made from rubber trees, this garentees it doesnt have a crystal structure.
Its not D because, concrete is not a mineral and has indefinite composition.
Adenine forms two hydrogen bonds with thymine in DNA while three hydrogen bonds are formed between guanine and cytosine.
Thymine and cytosine are pyrimidines because they have a single ring structure. Adenine and guanine are purines because they have a double ring structure.
the theory of plate tectonics states that the crust of earth is divided into plates which are slowly moving
Explanation:
Answer:
he term “homologous structures” refers specifically to similar structures found in different species that have a common ancestry or developmental origin. Note that homologous structures don’t have to perform the same function in a species, the only requirement is that they are similar in form and exist in species with common ancestry.
Explanation:
Answer:
c is just wrong because that is not how evolution works evolution is a small change in the DNA that takes a long time through many many generations not just as you or an organism get older and smarter you are not evolving