unit 4

If a DNA strand has the sequence 3' AGCATGCATGCA 5' what is the sequence of its complementary DNA strand?

5' TCGTACGTACGT 3'

If a newly-transcribed RNA strand has the sequence 3' AAGCCCUUGGA 5', what is the sequence of the DNA strand that was used as the template for transcription?

5' TTCGGGAACCT 3'

The genetic code is essentially the same for organisms. From this, one can logically assume which of the following?

A gene from an organism can theoretically be expressed by any other organism

What can be accomplished using genetic engineering?

A gene from any organism can be expressed in any other organism

Which of the following is characteristic of the lytic cycle?

A large number of phages are released at a time

Which enzyme was used to produce the staggered cut & sticky ends?

A restriction enzyme

How does termination of translation take place?

A stop codon is reached

What is the start codon?

AUG

Chronic Wasting disease, Mad Cow Disease, Creutzfeldt-Jakob Disease, and Scrapie are all diseases caused by prions. What are prions?

Abnormally-folded proteins

Yeast cells are frequently used as hosts for cloning because they....

Are eukaryotic cells

A major problem with inserting an unmodified eukaryotic gene into a plasmid and then getting that gene expressed in bacteria is that...

Bacteria cannot remove eukaryotic introns

Refer to the genetic code. What would the anticodon be for a tRNA that transports Glycine (Gly) to a ribosome?

CCC

What are exons?

Coding sequences; these are expressed after RNA splicing

The genetic code read in groups of three nucleotide bases is known as?

Codons

Who performed experiments that confirmed that codons are unspaced?

Crick and Brenner

In a prokaryotic cell, transcription takes place in the ______________, and translation takes place in the _____________.

Cytosol; cytosol

In an analysis of the nucleotide composition of DNA, which of the following will be found? A. A=C B. G+C = T+A C. A=G and C=T D. A+C = G+T

D. A+C = G+T because Chargaff's rule says A=T and G=C so G+C does not equal T+A

Genetic variation..... A. is created by the direct action of natural selection B. arises in response to changes in the environment C. tends to be reduced when diploid organisms produce gametes D. must be present in a population before natural selection can act upon the population

D. must be present in a population before natural selection can act upon the population

Suppose you are provided with an actively-dividing culture of E. Coli bacteria to which radioactive thymine (T) had been added. What would happen if a cell replicates once in the presence of this radioactive bacteria?

DNA in both daughter cells would be radioactive.

Which enzyme catalyzes the elongation of a DNA strand in the 5' > 3' direction?

DNA polymerase 3

A frameshift mutation could result from:

Either an insertion or a deletion of a base

What is the main structural difference between enveloped and nonenveloped viruses?

Enveloped viruses have a phospholipid membrane outside their capsid, whereas nonenveloped viruses do not have a phospholipid membrane

During the splicing of eukaryotic mRNA molecules, which of the following events occur?

Exons are joined together and introns are removed

The central dogma describes what?

Information flow as DNA to RNA to protein

Gene therapy has been suggested as a mechanism to help cure patients with Cystic Fibrosis. How would gene therapy treat this disease?

Introduction of new genes into the patient's genome

In the form of gene therapy used successfully for severe combined immunodeficiency syndrome (SCID)-X1, the genetic engineering of human cells is done by...

Isolating the patient's bone marrow cells, infecting them with genetic engineered viruses, and injecting them back into the patient's bone marrow

What is the effect of a silent mutation in a gene?

It has no effect on the amino acid sequence of the encoded protein

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?

It joins Okazaki fragments together.

The mRNA that codes for a particular eukaryotic protein is shown below: 5' UUU-CUC-UGA-AUG-CCG-GGG-AAU-GCA-UAA-GAC 3' What will be the amino acid sequence of this particular protein?

Met-Pro-Gly-Asn-Ala

The genetic code is described as being redundant. What does this mean?

More than one codon can specify the addition of the same amino acid

In eukaryotes, transcription occurs in the ___________, whereas translation takes place in the ______________.

Nucleus; Cytosol

How many RNA polymerases are found in prokaryotes? (idk if we need to know this)

One

Before a new DNA strand can be elongated during DNA replication, what enzyme must first produce a short stretch of RNA nucleotide that serve as a starting point?

Primase

In the process of transcription_________

RNA is synthesized (made)

Which of the eukaryotic RNA polymerases requires promoters that are internal to the gene itself?

RNA polymerase III

Which of the following viruses uses reverse transcriptase to make their RNA genome into DNA? A. Adenovirus B. Herpesvirus C. Poxvirus D. Retrovirus E. Rhinovirus

Retrovirus

Which viruses have single-stranded RNA that acts as a template for DNA synthesis

Retroviruses

Which enzyme can be used to produce DNA using an RNA template?

Reverse transcriptase

A gene that contains introns can be made shorter (but remain functional) for genetic engineering purposes by using ______________.

Reverse transcriptase to reconstruct the gene from its mRNA

Which of the following occurs in prokaryotes but not in eukaryotes?

Simultaneous transcription and translation

What is the process of pre-mRNA undergoes to create a functional mRNA?

Splicing

During what stage of transcription is the RNA transcript released from the DNA template?

Termination

You have just come down with a viral infection that is impacting your upper respiratory tract. What is the most likely reason that your pet dog has not become infected with the same virus?

The host range does not include dogs

What is the major difference between the leading and lagging strands of DNA that are produced during DNA replication?

The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction.

The host range of a virus is determined by _______________.

The proteins on its surface and that of the host

You use gel electrophoresis to separate two DNA fragments (a very small fragment and a very large fragment). Which fragment will migrate the fastest through the gel?

The smaller fragments

In transcription, the DNA strand that is not copied is called what?

The template strand

What sequence signals the location on a gene where the transcription should stop?

The terminator sequence

If the GAC codon shown: 5' UUU-CUC-UGA-AUG-CCG-GGG-AAU-GCA-UAA-GAC 3' mutates into GAA, what will happen to the encoded protein?

There will be no change in the protein

If the AUG codon shown: 5' UUU-CUC-UGA-AUG-CCG-GGG-AAU-GCA-UAA-GAC 3' mutates into CUG, what will happen to the encoded protein?

There will not be any of this protein made at all

In prokaryotes, how do translation and transcription occur?

They are coupled (same time)

What supports the argument that viruses are nonliving?

They cannot reproduce by themselves

Which of the following supports the argument that viruses are nonliving?

They cannot reproduce by themselves

What is the role of the promoter, in the bacteria unit?

To form a recognitioin and binding site for the RNA polymerase

What is the name of the process that makes an RNA copy of DNA

Transcription

In the central dogma what is the RNA to protein step called?

Translation

What is the function of transfer RNA in the synthesis of polypeptides from information contained in mRNA?

Translator

What are the three stop codons?

UUU, UAG, UGA

A major problem with inserting an unmodified eukaryotic gene into a plasmid and then getting that gene expressed in bacteria is that

bacteria cannot remove eukaryotic introns

What serves as a template for PCR amplification of the gene of interest

complementary DNA (cDNA)

Which of the following can be effective in preventing the onset of viral infection in humans?

getting vaccinated

What seals the sticky ends of restriction fragments to make recombinant DNA?

ligase

At the most basic level, what is the primary source of all genetic variation?

mutation

The shortening of chromosomes occurs in which types of cells?

only eukaryotic cells

What is the term that describes an alternative approach, in which the phenotype is determined by first studying the genotype?

reverse genetics

Anticodons are part of the molecular structure of ___________

tRNA

Stretches of non-coding DNA found at the ends of linear chromosomes are called_____________

telomeres

Which RNA functions as the translator between an mRNA codon and an amino acid?

transfer RNA

What four subunits is the core polymerase composed of? (idk if we need to know this)

two identical α subunits, a β' subunit and a β subunit

Which of the following evidence most strongly supports the common origin of all life on earth? All organisms....

use essentially the same genetic code