The gamete (sex cell ) for any species should always contain 1. An even number of chromosomes
2. The normal number of chromosomes
3. Twice the normal number of chromosomes
4. Half the normal number of chromosomes

The similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between organisms in both locations?

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins

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