How do heterotrophs depend on autotrophs? how do autotrophs depend on heterotrophs?

Prior to the development of dna fingerprinting, blood type could be used to determine possible parentage. although it might prove someone was not a parent, it could not show if someone was positively the parent, only that he or she might be a parent. which of the following is a true statement that can be made about parentage based on blood typing?

If a strand of dna has 35% thymine. what is the percentage of cytosine, adenine, guanine?

Interferons play a vital role in the immune system why are interferons so important?