What affect does insulin have on the body? a. it raises blood-sugar levels. b. it lowers blood-sugar levels. c. it raises glucagon levels. d. it lowers glucagon levels.

Which statement describes compounds a. compounds are made of one type of atom. b. compounds cannot be represented by models. c. compounds are represented by chemical formulas. d. compounds cannot be broken down into simpler forms.

Which of the following is not a type of epithelial cell

How are viruses different from eukaryotic cells?