Select the following phylum that includes animals that are unsegmented, acoelomate, and have a digestive cavity with a single opening.
A. Platyhelminthes
B. Nematoda
C. Rotifera
D. Annelida
E. Cnidaria
Answer: A
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Which of the following uses red blood cells?
A. MIC B. RIA C. Hemagglutination inhibition D. ELISA
PTH is necessary to produce calcitriol (activated vitamin D), which is necessary for the movement of calcium through cells. In this case, how would you characterize PTH?
A) submissive B) permissive C) synergistic D) antagonistic
Which is a byproduct of photosynthesis?
a. water b. light c. glucose d. oxygen e. carbon dioxide
Ras is a GTP-binding protein involved in cell proliferation (division). In its active form, with GTP bound, Ras activates cell signaling pathways that promote cell division. Mutations in the gene that encodes Ras can lead to cancer. How might mutations in the gene encoding Ras lead to the uncontrolled proliferation characteristic of cancer cells?
A.) they increase the rate at which Ras hydrolyzes GTP B.) they prevent Ras from being made C.) they decrease the rate at which Ras hydrolyzes GTP D.) they decrease the protein's affinity for GTP E.) they increase the protein's affinity for GDP