C scientific law is something that's always going to be true
Phenotypes are the way the animal looks, the Genotypes are the the genetic makeup: like BB or Bb or bb
Isotopes are atoms with the same atomic number but different atomic weights. Atoms of different isotopes are atoms of the same chemical element. They differ in the number of neutrons in the nucleus.
A human cell contains about 6 pg of DNA.
Or you can say there are 46 pairs or 92 single strands of DNA in each diploid human cell.