Which term defines a well-tested, scientifically supported statement that explains how something work?

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine

Is becoming less expensive to screen blood samples for dna certain diseases have genetic basis what is possible ethical concern about the availability of inexpensive dna testing