If we think of the DNA double helix as a twisted ladder, what makes up the rungs or steps of the ladder?
A. purines and pyrimidines
B. alternating phosphate groups and sugars
C. phosphate groups and bases
D. sugars only
E. phosphate groups only
Answer: A
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In microbial ecology studies, the FISH technique identifies organisms based on
A) the presence of green fluorescent protein. B) fluorescence of unique cofactors or pigments under certain wavelengths of UV light. C) hybridization of a fluorescent probe to specific ribosomal RNA sequences. D) the presence of luciferase.
Darker skin color is correlated with ____
a. the northern hemisphere b. inland regions c. coastal regions d. longitude e. the intensity of UV radiation
Each of the following statements concerning bacterial spores is correct EXCEPT:
A. They are formed by Gram-positive rods B. Their survival ability is based on their enhanced metabolic activity C. They can be killed by being heated to 121 C for 15 min D. They contain much less water than bacterial cells
________ consist of a core of segments of DNA or RNA surrounded by a protein coat.
A. Viruses B. Protists C. Archaea D. Bacteria