The four main types of macromolecules are organic. what does organic mean in this context. A. it is made only of carbon
B. it is produced without the use of pesticides.
C. it is a very large molecule.
D. it is made from or produced by a living organism.

Which of the following is a difference between a food chain and a food web? selected: a. food webs contain both plants and animals. food chains only contain animals.this answer is incorrect. b. food webs show energy transfer. food chains show which animal eats which animal. c. food webs separate organisms by tropic level. food chains do not. d. food webs are a complex patterns of energy flow. food chains only show one line of energy flow.

Which of the following will not cause mass extinction? a. drastic change is weather b. geological change c. both a and b d. none of the above

Which of the following is an example of a tissue on the digestive system a.the stomach b.smooth muscle that lines the stomach c.nerve cells in the stomach d. enzyme molecules in the stomach