Protein is essential to the overall health of the body because it
a. sustained life and keeps body systems in good repair
b. build up muscles
c. gives the body collagen which protects the organs
d. keeps hair and nails healthy

How does oxygen move from the respiratory system to the circulatory system? a. by pumping through the heart b. by circulating in an artery c. by moving across a synapse d. by diffusion across a capillary wall

What was the land like over 500 million years ago? what was under the sea?

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that a) the four organisms do not have a common ancestor. b) humans are more closely related to chimps than any other apes. c) chimps are more closely related to gorillas than they are to humans. eliminate d) there is no evidence if any relationship between the four branches on the tree.