Enzymes are important for allowing and speeding up reactions in an organism. They do this by orienting chemical compounds and or substances so that they can easily break and form new products easily, the activation energy is lowered upon the use of such enzymes.
See attached image for most common formula of sulfuric acid.
Answer:
Insertion mutation
Explanation:
An extra letter is added.
This can be because of their genetics. The siblings may not have inherited their parents looks, but maybe they inherited their grandparents looks, or even their aunts looks. This is all due to genetics. It's sort of the same thing, when two caucasian parents have an african-american child. That would be because somewhere along the family tree someone was african-american.
Anyways, I hope this helps!