MICROBIOLOGY: MS microbiology chapter 8 Flashcards

Transposition (insertion of a transposon into a DNA sequence) results in the formation of base substitution mutations in a cell's DNA

In the figure, if enzyme A is a repressible enzyme, compound C would

if you knew the sequence of nucleotides within a gene, which one of the following could you determine with the most accuracy?

A. the tertiary structure of the protein

B. the quaternary structure of the protein

C. the primary structure of the protein

D. the secondary structure of the protein

E. The answer cannot be determined based on the information provided.

In the figure, 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

Refer to the table The anticodon for valine is

An enzyme that catalyzes the cutting and resealing of DNA, and is translated from insertion sequences, is

• transposase
• RNA polymerase
• DNA helicase
• DNA polymerase
• DNA ligase

What is transformation?

1. The uptake of extracellular DNA
2. The horizontal gene transfer of bacterial DNA via a conjugation pilus
3. The horizontal gene transfer of bacterial DNA via a bacteriophage

Refer to the table. Identify the sequence of amino acids encoded by the following sequence of bases in a strand of DNA (pay attention to the polarity of the DNA here):
3' ATTACGCTTTGC 5'.

1. asparagine-cysteine-valine-serine
2. Translation would stop at the first codon
3. leucine-arginine-lysine-alanine
4. asparagine-arginine-lysine-alanine
5. The answer cannot be determined based on the information provided.

Conjugation differs from reproduction because conjugation

1. transfers DNA horizontally, to nearby cells without those cells undergoing replication.
2. transcribes DNA to RNA.
3. replicates DNA.
4. transfers DNA vertically, to new cells.
5. copies RNA to make DNA.

Refer to the table. When amino acid sequences from a cell cycle control protein from a patient with cancer and a healthy person are aligned, the sequence from the cancer patient indicates one amino acid has changed from phenylalanine (Phe) to leucine (Leu). A mutation in the cancer patient's DNA must have taken place. Identify the result of this DNA change in the mRNA codon that led to this change in the protein sequence.

1. UUU altered to UUA
2. UCU altered to UUA
3. CAA altered to UUU
4. UUU altered to UCU
5. UUU altered to UAU

An enzyme produced in response to the presence of a substrate is called a(n)

1. operator.
2. repressible enzyme.
3. restriction enzyme.
4. inducible enzyme.
5. promoter.

Both base substitution and frameshift mutations can result in the formation of premature stop codons.

True/False

Genetic change in bacteria can be brought about by

1. transduction.
2. conjugation.
3. mutation.
4. transformation.
5. All of the answers are correct.

Which of the following enzymes unwinds the two strands of DNA so that they can be copied during replication?

1. transposase
2. DNA polymerase
3. DNA gyrase
4. helicase

A gene is defined as

1. a sequence of nucleotides in DNA that codes for a functional product.
2. three nucleotides that code for an amino acid.
3. any random segment of DNA.
4. the RNA product of a transcribed section of DNA.
5. a sequence of nucleotides in RNA that codes for a functional product.

Recombination will always alter a cell's genotype.

True/False

The mechanism by which the presence of glucose inhibits the lac operon is

1. DNA polymerase.
2. induction.
3. repression.
4. catabolite repression.

In the figure, if enzyme A is an inducible enzyme,

1. compound A would react with enzyme B directly.
2. compound A would bind to the repressor for Gene a.
3. compound C would bind to the repressor for Gene a.
4. compound C would react with gene a directly.