Chap 16 Micro

transposons can cause mutations by

"jumping" into a gene and disrupting its function.

Which of the following synthesizes the new DNA strand? DNA helicase DNA ligase DNA polymerase UvrA-UvrB trimer

DNA polymerase

The most effective method by which antibiotic resistance can be decreased in bacteria is

Decrease in use

Excision repair takes place only in the presence of light. False True

False

In the lysogenic stage of phage replication, the host cell is lysed. True False

False

Once a phage becomes lysogenic, it will remain lysogenic and never be lytic again. True False

False

T/F In a frameshift mutation all of the amino acids before the shift are changed.

False

Choose the term below that best describes a bacterium that has had its genotype changed by transduction.

Recombinant cell

_____________ mutations arise occasionally in all cells and in the absence of any added agent.

Spontaneous

A mutation that causes a change in a single nucleotide in DNA

changes the corresponding nucleotide in mRNA, resulting in a different codon.

Transformation with a linear DNA fragment may result in

either homologous recombination or unsuccessful transformation.

The mismatch repair system will repair

either the donor or the recipient strand

In a tautomeric shift

hydrogen atoms move to form a base with altered hydrogen properties.

A short sequence of DNA that contains only the gene for the enzyme transposase, and is bounded at both ends by inverted repeats is known as a(n)

insertion sequence

The ends of a simple transposable element contain

inverted repeats

When DNA is damaged by UV light and is not repaired

neither DNA replication nor transcription can occur and the organism will probably die.

When DNA from an ampicillin resistant organism is brought into an ampicillin sensitive organism by transformation and the product is grown on agar containing ampicillin

only the transformed cells will grow.

A prophage is phage DNA being actively expressed. phage protein left outside the bacterium. toxic to the host bacterial cell. phage DNA integrated into host cell genome.

phage DNA integrated into host cell genome.

In the lytic cycle of phage replication,

phage nucleic acid is replicated and phage genes are expressed, making new phage protein and lysing the host cell.

Generalized transduction occurs during

the lytic cycle of virulent and some temperate phages.

If a frameshift mutation causes a stop codon to be inserted into the DNA sequence

the resulting protein will be too short and nonfunctional.

UV light damages DNA molecules by causing the formation of

thymine dimers between adjacent thymines in the DNA chain.

UV light damages DNA by causing covalent bonds to form between two thymine nucleotides on opposing DNA strands. thymine nucleotides next to each other on the same DNA strand. two cytosines next to each other on the same DNA strand. a thymine and an adenine on the same DNA strand.

thymine nucleotides next to each other on the same DNA strand.

In dark repair, the final phosphodiester bond is formed by DNA ligase. True false

true

Choose the conditions listed below that can cause a phage in the lysogenic cycle to revert to the lytic cycle. darkness lack of nutrients an electrical charge a competing phage ultraviolet light

UV light