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

a. 4,000,000

b. 4000

c. 400

d. 40

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

a. They typically have two or three origins of replication

b. They contain single-stranded DNA

c. They are located in the cytosol

d. They are associated in linear pairs

A plasmid is __________ .

a. a molecule of RNA found in bacterial cells

b. distinguished from a chromosome by being circular

c. a structure in bacterial cells formed from plasma membrane

d. extrachromosomal DNA

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

a. Chromatin

b. Bacteriocin

c. Histone

d. Nucleoid

Nucleotides used in the replication of DNA __________ .

a. Carry energy

b. Are found in four forms, each with a deoxyribose sugar, a phosphate, and a base

c. Are present in cells as triphosphate nucleotides

d. All of the above are correct.

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

a. DNA polymerase III

b. Primase

c. Helicase

d. Ligase

The addition of a ----CH₃ to a cytosine nucleotide after DNA replication is called: .

a. Methylation

b. Restriction

c. Transcription

d. Transversion

In translation, the site through which tRNA molecules leave a ribosome is called the:

a. A site

b. X site

c. P site

d. E site

The Ames test ___________.

a. uses auxotrophs and liver extract to reveal mutagens

b. s time intensive and costly

c. involves the isolation of a mutant by eliminating wild-type phenotypes with specific media

d. proves that suspected chemicals are carcinogenic

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

a. Light repair of T dimers

b. Dark repair of P dimers

c. Mismatch repair

d. SOS response

Which of the following is not a mechanism of genetic transfer between cells?

a. Transduction

b. Transformation

c. Transcription

d. Conjugation

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

a. Hfr cells

b. transposing

c. genomic

d. competent

Which of the following statements is true?

a. Conjugation requires a sex pilus extending from the surface of a cell.

b. Conjugation involves a C factor.

c. Conjugation is an artificial genetic engineering technique.

d. Conjugation involves DNA that has been released into the environment.

Which of the following are called “jumping genes”?

a. Hfr cells

b. Transducing phages

c. Palindromic sequences

d. Transposons

Although two cells are totally unrelated, one cell receives DNA from the other cell and incorporates this new DNA into its chromosome. This process is ___________.

a. crossing over of DNA from the two cells

b. vertical gene transfer

c. horizontal gene transfer

d. transposition

Transcription produces:

a. DNA molecules

b. RNA molecules

c. Polypeptides

d. Palindromes

A nucleotide is made of:

a. A five-carbon sugar

b. Phosphate

c. A nitrogenous base

d. All of the above

A sequence of nucleotides formed during replication of the lagging DNA strand is a(n):

a. Palindrome

b. Okazaki fragment

c. Coding strand

d. Operon

Which of the following is not part of an operon?

a. Operator

b. Promoter

c. Origin

d. Gene

Repressible operons are important in regulating prokaryotic:

a. DNA replication

b. RNA transcription

c. rRNA processing

d. Sugar catabolism

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

a. Palindrome

b. Codon

c. Anticodon

d. Base pair

Ligase plays a major role in:

a. Replication of lagging strands

b. mRNA processing in eukaryotes

c. Polypeptide synthesis by ribosomes

d. RNA transcription

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

a. lasting

b. inheritable

c. beneficial

d. all of the above

The trp operon is repressible. This means it is usually __________ and is directly controlled by a(n) ___________ .

a. active / inducer

b. active / repressor

c. inactive / inducer

d. inactive /repressor

The three steps in RNA transcription are __________ , ___________ , and __________ .

A triplet of mRNA nucleotides that specifies a particular amino acid is called a ____________  .

Three effects of point mutations are ___________ , ___________ , and ____________ .

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

An operon consists of __________ , ___________ , and __________ , and is associated with a regulatory gene.

In general, __________ operons are inactive until the substrate of their genes’ polypeptides is present.