Veins take blood back to the heart. which gas would be most abundant in a vein that takes blood from muscle cells in the arm back to the heart? a) carbon dioxide b) oxygen c) nitrogen d) hydrogen

Organisms are classified, or grouped into categories, based on similarities in their characteristics and/or evolutionary relationships. the study of how organisms are classified is known as

Indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. assume all are homozygous. albino x albino a) 1/4 chinchilla, 3/4, agouti b) 3/4 albino, 1/4 chinchilla c) all albino

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