Advertisement Upgrade to remove ads

A uracil nucleotide is a _____ nitrogenous base attached to the _____, with the 5' carbon of the sugar attached to a phosphate group.

one-ringed ... carbon of a sugar that has an OH group at the 2' carbon

During DNA replication, _____.

each parental strand serves as a template for the synthesis of a complementary strand

The information carried by a DNA molecule is in _____.

the order of the nucleotides in the molecule

How does RNA polymerase know where to start transcribing a gene into mRNA?

It starts at a certain nucleotide sequence called a promoter.

After an RNA molecule is transcribed from a eukaryotic gene, portions called _____ are removed and the remaining _____ are spliced together to produce an mRNA molecule with a continuous coding sequence.

introns ... exons

Which of the following is true of tRNAs?

Each tRNA binds a particular amino acid.

Which of the following build(s) new strands of DNA?
Parental DNA
The leading strand
The lagging strand
The origins of replication
DNA polymerases

DNA polymerases

Which statement about DNA replication is CORRECT?
DNA ligase helps assemble the leading strand.
The lagging strand is one of the strands of parental DNA.
The leading strand is one of the strands of parental DNA.
The lagging strand is built continuously.
The leading strand is built continuously, and the lagging strand is built in pieces.

The leading strand is built continuously, and the lagging strand is built in pieces.

During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA?


The molecule that seals the gaps between the pieces of DNA in the lagging strand is
the leading strand.
DNA ligase.
DNA polymerase.
the replication fork.

DNA ligase.

Which statement about DNA replication is FALSE?
The lagging strand is made of a series of pieces that must be joined together to make a continuous strand.
DNA polymerase builds a new strand by adding DNA nucleotides one at a time.
DNA ligase adds nucleotides to the lagging strand.
Because the two strands of parental DNA run in opposite directions, the new strands must be made in different ways.
The two strands of parental DNA are separated during DNA replication.

DNA ligase adds nucleotides to the lagging strand.

Which of the following events occurs during transcription?
The message in mRNA is translated into a protein.
mRNA binds to a ribosome in the cytoplasm.
A molecule of RNA is formed based on the sequence of nucleotides in DNA.
Those segments of the RNA strand that do not actually code for the protein are removed.
A cap is added to the RNA molecule.

A molecule of RNA is formed based on the sequence of nucleotides in DNA.

Which of the following is a correct statement about mRNA?
mRNA binds directly to amino acids during translation.
mRNA moves from the nucleus to the cytoplasm following RNA processing.
mRNA includes a cap that consists of extra adenine nucleotides.
Segments of mRNA that code for protein are removed before translation.
mRNA is transcribed from DNA in the cytoplasm.

mRNA moves from the nucleus to the cytoplasm following RNA processing.

The site of translation is

ribosomes in the cell cytoplasm.

Which one of the following does not play a role in translation?
Amino acids


Which of the following does not occur during RNA processing?
Segments of the RNA strand that do not actually code for the protein are removed.
Segments of RNA that do code for the protein are reconnected.
A modified guanine nucleotide is added to the beginning of the RNA strand as a cap.
mRNA attaches to the small subunit of a ribosome.
Adenine nucleotides are added to the end of the RNA strand, forming a tail.

mRNA attaches to the small subunit of a ribosome.

Which of these correctly illustrates the pairing of DNA and RNA nucleotides?






The direction of synthesis of an RNA transcript is _____.

5' —> 3'

What enzyme catalyzes the attachment of an amino acid to tRNA?

aminoacyl-tRNA synthetase

The tRNA anticodon, GAC, is complementary to the mRNA codon with the sequence _____.


The initiator tRNA attaches at the ribosome's _____ site.


How do mutations affect an organism?
all of the above

all of the above

DNA replication occurs at an unbelievably fast rate. Once replication is complete, we can expect to find a _____ number of mistakes.


A female that is planning to become pregnant is concerned about her exposure to environmental mutagens which may have caused DNA mutations. In order for these mutations to become heritable, they must affect the:

her egg cells

Which of the following would indicate a base pairing mutation in DNA?

a G paired with a T

molecular biology

The study of the molecular basis of genes and gene expression

bacteriophages aka phages

viruses that infect bacteria


A polymer consisting of many nucleotide monomers in a chain; nucleotides can be those of DNA or RNA.

the four nucleotides found in DNA

thymine cytosine, adenine and guanine

the four nucleotides found in RNA

Uracil, cytosine, adenine and guanine

semiconservative model

Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand.

DNA polymerases

enzymes that add complementary nucleotides to each of the original strands

DNA ligase

A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.


(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA


the synthesis of a polypeptide using the genetic information encoded in an mRNA molecule.

triplet code

A set of three-nucleotide-long words that specify the amino acids for polypeptide chains


three-nucleotide sequence of mRNA that codes for a single amino acid

genetic code

the set of rules that dictates the correspondence between RNA codons in an mRNA molecule and amino acids in protein

RNA polymerase

a large molecular complex that links together the growing chain of RNA nucleotides during transcription, using a DNA strand as a template.


A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing RNA.


A special sequence of nucleotides in DNA that marks the end of a gene. It signals RNA polymerase to release the newly made RNA molecule, which then departs from the gene


the type of RNA that encodes genectic info from DNA and conveys it to ribosomes, where the info is translated into amino acid sequences


a non-coding, intervening sequence within a eukaryotic gene


A coding region of a eukaryotic gene. Exons, which are expressed, are separated from each other by introns.

RNA splicing

process by which the introns are removed from RNA transcripts and the remaining exons are joined together

transfer RNA (tRNA)

type of RNA molecule that transfers amino acids to ribosomes during protein synthesis


group of three bases on a tRNA molecule that are complementary to an mRNA codon

ribosomal RNA (rRNA)

RNA component of ribosomes


production of mutations

lytic cycle

a viral reproductive cycle in which copies of a virus are made within a host cell, which then bursts open, releasing new viruses

lysogenic cycle

cycle in which a viral genome replicates as a provirus without destroying the host cell

reverse transcriptase

an enzyme that catalyzes the formation of DNA from an RNA template


an RNA virus that reproduces by means of a DNA molecule


infectious proteins


the take up of foreign DNA from surrounding environment


the transfer of bacterial genes by a phage

F factor

A fertility factor in bacteria; a DNA segment that confers the ability to form pili for conjugation and associated functions required for the transfer of DNA from donor to recipient. It may exist as a plasmid or be integrated into the bacterial chromosome.


circular DNA molecule found in bacteria

R plasmids

carry genes for antibiotic resistance

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording