In a multicellular organism like an animal or a plant, it is cell-to-cell communication that allows the trillions of cells in an organism to coordinate life-dependent activities. To do this, cells within an organism exchange cellular molecules, including RNA. In plants specifically, this exchange can trigger acclimation to environmental changes, transfer of nutrients, and growth. Why is this study important?

The number of different amino acids is:

a. 10. b. 20. c. 30. d. 40. e. 50.

Use the BLAST tool at http://blast.ncbi.nlm.nih.gov/Blast.cgi and click "Protein blast" to find out the identity of the protein with the following amino acid sequence:

A) myosin B) actin C) albumin D) DNA polymerase E) tubulin

A viral genome may consist of __________

a. double-stranded DNA b. single-stranded DNA c. double-stranded RNA d. single-stranded RNA e. Any of the above

Which of the following is greater?

A) the number of reported cases of gonorrhea last year B) the number of reported cases of AIDS last year C) The number of reported cases of gonorrhea and AIDS are likely equal.