How many genotypes and phenotypes are expected when you cross 2 heterozygous organisms?

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

Cells must be in osmotic equilibrium with their surroundings environments because if they swell or shrink thier membranes will rupture

What characteristic makes a cell membrane selectively permeable