Which of the following molecules are used by heterotrophs as primary sources of free energy? A. Proteins, carbohydrates, and nucleic acids
B. Carbohydrates, lipids, and proteins
C. Nucleic acids, lipids, and carbohydrates
D. Lipids, nucleic acids, and proteins

Use this dichotomous key for insect identification to identify the insect shown. 1. a. insect has one pair of wings. order diptera b. insect has two pairs of wings. go to #2 2. a. front wings thicker in texture than hind wings go to #3. b. front and hind wings are same texture throughout. go to #4 3. a. front wings are short order dermaptera b. front wings cover entire abdomen order coleoptera 4. a. wings with scale on all parts of their area. order lepidoptera b. wings without scales go to #5. 5. a. hind wings smaller than front wings. order ephemeroptera b. front and hind wings nearly equal in size. order odonata the insect pictured is in the order diptera. ephemeroptera. coleoptera. odonata.

The cell membrane controls what enters and leaves the cell. which of the structures in the diagram below is the cell membrane? — f о

Question 17 (1 point) where does penicillin come from? a. it is a chemical that man invented b. it is a fungus c. it is a toxin made by other bacteria d. it was discovered in archaebacteria