The likelihood of a specific outcome in relation to the total number of possible outcomes

All ova contain sex chromosomes corresponding to: x y xx xy

Why do some dna fragments move farther than others during gel electrophoresis? a. because their shapes are different b. because they are different types of molecules c. because the samples are different colors d. because their masses are different

Which of the following is an eon in the time scale? phanerozoic proterozoic archean all of the above