microbiology chapter 7 potential test questions Flashcards

Which of the following is most likely the number of base pairs in a bacterial chromosome?

1. 4,000,000
2. 4,000
3. 400
4. 40

which of the following is a true statement concerning prokaryotic chromosomes?

1. they typically have two ro three origins of replication
2. they contain single stranded DNA
3. they are located in the cytosol
4. they are associated in linear parts

3. A plasmid is ___________________________.

1. a molecule of RNA found in bacterial cells
2. distinguished from a chromosome by being circular
3. a structure in bacterial cells formed from plasma membrane
4. extrachromosomal DNA

Which of the followiing forms ionic bonds with eukaryotic DNA and stabilizes it?

1. chromatin
2. bacteriocin
3. histone
4. nucleoid

Nucleotides used in the replication of DNA _____________.

1. carry energy
2. are found in four forms, each with a deoxyribose sugar, a phosphate, and a base
3. are present in cells as triphosphate nucleotides
4. all of the above

Which of the following molecules functions as a proofreader for a newly replicated strand of DNA?

1. DNA polymerase III
2. primase
3. helicase
4. ligase

9 the Ames test __________________.

1. uses autotrophs and liver extract to reveal mutagens
2. is time intensive and costly
3. involves the isolation of a mutant by eliminating wild-type phenotypes with specific media

10 Which of the following methods of DNA repair involve enzymes and recognize and correct nucleotide errors in unmethylated strands of DNA?

1. light repair of T dimers
2. dark repair of P dimers
3. transcription
4. SOS response

11 Which of the following is not a mechanism of natural genetic transfer and recombination?

1. transduction
2. transformation
3. transcription
4. conjugation

12 Cells that have the ability to take up DNA from their environment are said to be _______________.

1. Hfr cells
2. transposing
3. genomic
4. competent

13 Which of the following statements is true

1. conjugation requires a sex pilus extending from the surface of a cell
2. conjugation involves a C factor
3. conjugation is an artificial genetic engineering technique
4. conjugation involves DNA that has been released in to the environment

14 Which of the following are called jumping genes?

1. Hfr cells
2. transducing phages
3. palindromic sequences
4. transposons

16 Transcription produces ________________

1. DNA molecules
2. RNA molecules
3. polypeptides
4. palindromes

17 A nucleotide is composed of _____________________.

1. a five carbon sugar
2. phosphate
3. a nitrogenous base
4. all of the above

20 Which of the following is not part of an operon?

1. operator
2. promoter
3. origin
4. gene

21 Repressible operons are important in regulating prokaryotic

_______________

1. DNA replication
2. RNA transcription
3. rRNA processing
4. sugar catabolism

22 Which of the following is part of each molecule of mRNA?

1. palindome
2. codon
3. anticodon
4. base pair

23 Ligase plays a major role in ________________

1. lagging strand replication
2. mRNA processing in eukaryotes
3. polypeptide synthesis by ribosomes
4. RNA transcripton

24 Before mutations can affect a population permanently, they must be _________________.

1. lasting
2. inheritable
3. beneficial
4. all of the above

A triple of mRNA nucleotides that specifies a particular amino acid is called a _____________.

Insertions and deletions in the genetic code are also called ___________ mutations.

An operon consists of ______, ______, and ________ and is associated with a regulatory game.

A gene for antibiotic resistance can move horizontally among bacterial cells by ________, _________, and ________.