When is observation a better tool for proving a hypothesis than experimentation?

Aperson with age is more likely to catch diseases that healthy people usually don’t catch.what are these infections called?

Guinea pig coat color is determined by a single gene. the allele for black coat color is dominant to brown. in a cross between twoblack-haired guinea pigs, 20 offspring are born. if both parents were heterozygous, probability would predict that approximately howmany of the 20 offspring would have brown hair?

Dna, in the nucleus carries the genetic code for making proteins in ribosomes. in the diagram, b, represents the proteins produced. dna cannot leave the nucleus to carry the genetic information to the ribosome where proteins are produced. how does the genetic code get from the nucleus to the ribosome? what does a represent? now