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MCB 2010C Microbiology Exam 3 NEW 2024|
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A gene is defined as __________. A. a sequence of nucleotides in DNA that codes for a functional product B. a sequence of nucleotides in RNA that codes for a functional product C. three nucleotides that code for an amino acid D. the RNA product of a transcribed section of DNA A. a sequence of nucleotides in DNA that codes for a functional product DNA instructs cellular functions, transcribed to RNA in transcription and translated to proteins. Three- nucleotide sequences coding for amino acids are called codons. true or false? Multiple replication forks are possible on a bacterial chromosome: true Bacterial chromosomes, circular in structure, feature multiple replication origins. Each origin acts as a
starting point for a replication complex assembly, involving DNA helicase, DNA polymerase, and accessory proteins. true or false The lagging strand of DNA is started by an RNA primer. true DNA replication starts with RNA primers, short sequences of RNA nucleotides made by primase, a specialized RNA polymerase enzyme. true or false DNA polymerase joins nucleotides in one direction (5' to 3') only. true DNA polymerase adds nucleotides to the 3' end of a growing DNA strand, causing DNA synthesis to occur in the 5' to 3' direction. True or False? Pure cultures of the same species are not always identical in all ways. true For a serological bacterial identification test to be performed, you must have __________ in your possession.
When performing phage typing to identify an unknown bacterium, you must have __________ in your possession. A. DNA that will hybridize to the DNA of the bacterium to be identified B. RNA that will hybridize to the RNA of the bacterium to be identified C. antiserum containing antibodies that will bind to the bacterium to be identified D. fluorescent molecules that will light up when bound to the DNA of the bacterium E. viruses that will specifically infect the bacterium you're trying to identify E. viruses that will specifically infect the bacterium you're trying to identify Which one of the following characteristics most reasonably indicates that two microorganisms are closely related? A. Both are cocci. B. Both ferment lactose. C. Both are motile. D. Their DNA can hybridize together. E. Both normally live in clams. D. Their DNA can hybridize together.
One of the most popular taxonomic tools is DNA fingerprinting to develop profiles of organisms. These profiles provide direct information about __________. A. the similarities between nucleotide sequences B. protein composition C. the presence of specific genes D. antigenic composition E. enzymatic activities A. the similarities between nucleotide sequences Organism A has 55% G+C and organism B has 75% G+C. Which of the following can be concluded from these data? A. The two organisms are unrelated. B. The two organisms are related. C. The organisms make entirely different enzymes.
Eukaryotic yes cell wall-chitin both mitosis and meiosis Protozoa Eukaryotic no cell wall both mitosis and meiosis algae eukaryotes yes cell wall - cellulose both mitosis and meiosis Viruses
acellular no cell wall reproduction? neither use the host cell they infest! assuming this is an infection like influenza in the US, what does a refer to on the graph? a-endemic level b-epidemic level c-pandemic level d-increase of cases at the beginning of the infection e-decrease of cases at the end of the infection b-epidemic level - graph is only the US so its focused on an epidemic. c-pandemic = worldwide letters: a - highest level
b c d 2 3 B - the branches that are the closest to each either will be most closely related Which of the following pairs is MISMATCHED? A. DNA polymerase - makes a molecule of DNA from a DNA template B. DNA gyrase - relaxes supercoiling in DNA ahead of the replication fork C. RNA polymerase - makes a molecule of RNA from an RNA template D. primase - adds a short RNA sequence creating a double-stranded region C. RNA polymerase - makes a molecule of RNA from an RNA template RNA polymerase does make a molecule of RNA, but it is made from the sequence in DNA.
using DNA fingerprints you have the results below. which two are most closely related? 1 - 2 1 - 3 4 - 5 2 - 6 3 - 6 1 - 3 An enzyme that makes covalent bonds between Okazaki fragments in the lagging strand of DNA is __________. A. DNA helicase B. SSBP (single-strand binding proteins) C. RNA polymerase D. DNA ligase D. DNA ligase Ligation is to join DNA strands in this sense. In the medical field it is to close off a vessel, duct or tube in the body using a ligature or clip. DNA helicase opens the helix by breaking the hydrogen bonds between
DNA is constructed of __________. A. two strands of identical nucleotides in a parallel configuration with hydrogen bonds between them B. two strands of nucleotides running in an antiparallel configuration C. two complementary strands of nucleotides bonded A-C and G-T D. a single strand of nucleotides with internal hydrogen bonding B. two strands of nucleotides running in an antiparallel configuration DNA is a double-helix joined by hydrogen bonds between complimentary base pairs (A-T and C-G) and it has an antiparallel configuration meaning the 5' and 3' ends are opposite. A single strand of nucleotides with internal hydrogen bonding would represent RNA. Which of the following statements is FALSE? A. Multiple replication forks are possible on a bacterial chromosome. B. DNA polymerase joins nucleotides in one direction (5' to 3') only. C. The lagging strand of DNA is started by an RNA primer. D. DNA replication proceeds in only one direction.
D. DNA replication proceeds in only one direction. DNA replication is bidirectional, so enzymes can move to copy the DNA in two directions. That means there will be more than one replication fork. DNA polymerase does build the new DNA strand from the 5' to 3' direction. Both strands, the leading and the lagging strands, start with an RNA primer because DNA polymerase cannot bind to single-stranded DNA. Which of the following is NOT a product of transcription? A. a new strand of DNA B. rRNA C. mRNA D. tRNA A. a new strand of DNA Transcription is converting DNA to RNA, any type of RNA. A new strand of DNA would be made using DNA replication.
if base 6 is guanine what is the base 13'? guanine two new copies of DNA are identical, the bases for 1-6 will be identical to 8'-13' Base 5 (and ONLY the base) is covalently bound/attached to __________. A. phosphate B. ribose C. deoxyribose D. thymine E. The answer cannot be determined based on the information provided. C. deoxyribose The antibiotic chloramphenicol binds the 50S large subunit of a ribosome as shown (the light gray area is the large subunit, while the black shape is the drug). From this information, you can conclude that chloramphenicol A. prevents translation in eukaryotes.
B. prevents transcription in eukaryotes. C. prevents mRNA-ribosome binding. D. prevents transcription in prokaryotes. E. prevents translation in prokaryotes. E. prevents translation in prokaryotes. Ribosomes:
- Prokaryotic - 30S small, 50S large, 70S total
- Eukaryotic - 40S small, 60S large, 80S total Small subunit - mRNA binds Large subunit - builds amino acid chain (protein) Transcription is DNA to RNA Translation is RNA to protein The necessary ingredients for DNA synthesis can be mixed together in a test tube. The DNA polymerase is from Thermus aquaticus, and the template is from a human cell. The DNA synthesized would be most similar to __________. A. T. aquaticus DNA. B. a mixture of human and T. aquaticus DNA.
Genes for antibiotic resistance are most often found on plasmids. The transfer of a plasmid from one bacterial cell to another occurs due to conjugation, direct cell-to-cell contact. Transduction is the transfer of DNA by a bacteriophage and transformation is the update of free or naked DNA. Binary fission is the way prokaryotes divide. Transformation is the transfer of DNA from a donor to a recipient cell __________. A. by crossing over B. as naked DNA in solution C. by a bacteriophage D. by cell-to-cell contact B. as naked DNA in solution Think of the "f" in transformation and link it to free or naked DNA to help differentiate it from transduction. Genetic change in bacteria can be brought about by __________. A. mutation B. transduction C. conjugation
D. All of the answers are correct. D. All of the answers are correct. The four primary ways that bacteria can change their genetic material, since they are not sexually reproducing organisms, are mutation, transformation, conjugation and transduction. The DNA damage caused by ultraviolet radiation is __________. A. repaired during translation B. repaired by DNA replication C. cut out D. repaired during transcription C. cut out If the cell tries to repair the pyrimidine dimer (most often two Ts) it will be repaired in the DNA itself. When it cannot be repaired the cell will cut out the pair and link the rest of the DNA back together. This could then lead to a frameshift mutation because two base pairs were removed. The mechanism by which the presence of glucose inhibits the lac operon is __________. A. translation
