The source of variation among microorganisms that were once identical is
A. antibiotic resistance.
B. virulence factors.
C. sigma factors.
D. mutation.
The characteristics displayed by an organism in any given environment is its
A. genotype.
B. archaetype.
C. mutatotype.
D. phenotype.
The properties of a cell that are determined by its DNA composition are its
A. phenotype.
B. genotype.
C. metabolism.
D. nucleoid.
Cells are often ground up with abrasive to get to their internal enzymes/molecules, followed by removal of the abrasives. Here are three situations and three outcomes. What is the correct interpretation of the results?
In situation 1, radioactive amino acids are added to cell material, and radioactive proteins are produced. In situation 2, radioactive amino acids, cell material, and the enzyme DNAse (degrades DNA) are added together. Radioactive proteins are still produced. In situation 3, the ground-up cell material is allowed to sit for 24 hours before radioactive amino acids and DNAse are added to it. No radioactive protein is produced. What is the most likely interpretation?
A.
RNA polymerase has no activity after 24 hours, so no mRNA is transcribed and translated into radioactive proteinsin the last scenario.
B. The radioactivity in the amino acids is altering/degrading the tRNA molecules, leading to no protein production in the last scenario.
C.
Natural RNAses present in the ground-up material will degrade any existing mRNAs in that 24-hour interval. Added DNAses breakdown DNA so that new RNAs are not synthesized.This will lead to a loss of capability to translate protein in the last scenario.
D. The results are not interpretable from the information given.
Cells are often ground up with abrasive to get to their internal enzymes/molecules, followed by removal of the abrasives.
Here are two situations and two outcomes. What is the correct interpretation of the results? In situation 1, radioactive amino acids are mixed with ground-up cell material. Radioactive proteins are produced. In situation 2, radioactive amino acids AND the enzyme RNAse (an enzyme that degrades RNA) are mixed with ground-up cell material. No radioactive proteins are produced.
A. The mRNA from the cell can be used to make proteins with the radioactive amino acids in the first situation. In the second situation, the mRNA is destroyed by the RNAse before it can be translated into protein containing the radioactive amino acids.
B. The DNA from the cell can be translated into protein using the radioactive amino acids in the first situation. The RNAse in the second situation degrades the ribosomal RNA (rRNA), preventing ribosomes from forming and making proteins with the radioactive amino acids.
C. The radioactivity in the amino acids corrupts the tRNA molecules, leading to no protein production in the second scenario.
D. The results cannot be interpreted-there isn't enough information given in the question.
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