Which of the following is another name for the columns on the periodic table? Rows
Groups
Periods

List two limitations of natural selection

Match the examples to the correct level of organization. 1. system level roses, snakes, puppies 2. organism level roots, stamens, leaves 3. tissue level bone, cartilage, blood 4. organ level heart, veins, arteries

Nucleic acid certain protein cell membranes certain carbohydrates