What are the four levels of organization in living things? a. cell, multicellular, organ, organ system b. single cell, multicellular, tissue, organ c. larger size, longer life, specialized cells, organs d. cell, tissue, organ, organ system

Step 1 review the imaginary strand of dna below. note the complementary base pairs. a g c a a t c c g t c t t g g t c g t t a g g c a g a a c c step 2 to begin replicating this strand of dna, draw the two sides of the strand separating. step 3 now, draw the free-floating bases linking up with the separate sides. remember to follow the rules of complementary base pairing. step 4 draw the two resulting dna strands.

When is your breathing likely to speed up? a. when your white blood cells increase b. when your cells need more energy c. when your heart cells need more carbon dioxide d. when your blood cells have too much oxygen

Read the article and use the information to answer the following questions. active transport in active transport, molecules are moved across the cell membrane with the of neurons electrical impulses proteins. inhibitors 3 of 3 vity