This is a poisonous substance that is produced by living cells or organisms and is capable of causing disease when introduced into living tissues.

Which of these sources of energy have not acquired energy from sun? A. Petroleum B. Wind C. Coal

Nuclei in somatic cells of the freshwater alga Draparnaldia plumosa have 13 chromosomes. In the closely related species Draparnaldia acuta, nuclei in somatic cells have 26 chromosomes. Which of the following is correct: a.

Which type of diagram illustrates the flow of energy through a whole community or ecosystem? A. food web B. food chain C. energy plate D. energy pyramid

Several scientist make the same observations about the effect of sunlight on algae. this set of observations forms a?

During the laboratory, the students laid the food samples on brown paper, like the kind of paper that lunch bags are made out of. Both the chip and the pecan left translucent spots on the brown paper.

How do cells correct errors in DNA that would disrupt their function

Which is true of oxidation? a) It is a physical process b) No change occurs in the makeup of rock c) Rocks weather at different rates d) Water freezes in cracks in rock

What is the function of the pigment molecules in a light-harvesting complex in the thylakoid membranes?

How do natural actions such as weathering, erosion, and soil formation affect Earth's surface?

In which species of animal does sebum eventually become lanolin?