Bio 203 Clicker Questions and Extra Credit Quizzes

Use the following information to answer the question. The enzyme polynucleotide phosphorylase randomly assembles nucleotides into a polynucleotide polymer. You add polynucleotide phosphorylase to a solution of adenosine triphosphate and guanosine triphosphate. How many artificial mRNA 3 nucleotide codons would be possible?

8

In recent times, it has been shown that adult cells can be induced to become pluripotent stem cells (iPS). In order to make this conversion, what has been done to the adult cells?

A retrovirus is used to introduce four specific regulatory genes.

How does RNA Polymerase initiate transcription in E. coli or Salmonella enterica?

Binds to the promoter

Identify this molecule: 3'-ATCGGCAGGACCTTAAAT- 5' 5'-TAGCCGTCCTGGAATTTA- 3'

DNA; because there's two strands and presence of thymine

Which of the following is one of the technical reasons why gene therapy is problematic?

Transferred genes may not have appropriately controlled activity.

A researcher needs to clone a particular DNA sequence in order to express the sequence and to modify the polypeptide product. She would be able to satisfy these requirements by using which of the following vectors?

a yeast plasmid

The role of a metabolite that controls a repressible operon is to

bind to the repressor protein and activate it.

The lactose operon is likely to be transcribed when

the cyclic AMP and lactose levels are both high within the cell.

What is considered to be the first evidence of differentiation in the cells of an embryo?

the occurrence of mRNAs for the production of tissue-specific proteins

Which of the following is the first event to take place in translation in eukaryotes?

the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA

BRCA1 and BRCA2 are considered to be tumor-suppressor genes because

their normal products participate in repair of DNA damage.

RNAi methodology uses double-stranded pieces of RNA to trigger breakdown of a specific mRNA or inhibition of its translation. For which of the following might this technique be useful?

to decrease the production from a harmful mutated gene

A particular triplet of bases in the template strand of DNA is 5'AGT 3'. The corresponding codon for the mRNA transcribed is

3' UCA 5'

Transcribe this DNA molecule- Assume the bottom strand is the template: 3'-ATCGGCAGGACCTTA- 5' 5'-TAGCCGTCCTGGAAT- 3'

3'-AUCGGCAGGACCUUA- 5'

RNA polymerase moves in which direction along the DNA?

3'to 5' along the template strand

A peptide has the sequence NH2-phe- pro-lys- gly-phe- pro-COOH. Which of the following sequences in the coding strand of the DNA could code for this peptide?

5' TTT-CCC- AAA-GGG- TTT-CCC

Which of the following does not occur in prokaryotic gene expression, but does in eukaryotic gene expression?

A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end

Which of the following mechanisms is (are) used to coordinate the expression of multiple, related genes in eukaryotic cells?

A specific combination of control elements in each gene's enhancer coordinates the simultaneous activation of the genes.

Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If she moves the promoter for the lac operon to the region between the beta galactosidase (lacZ) gene and the permease (lacY) gene, which of the following would be likely?

Beta galactosidase will not be produced.

How does RNA Polymerase II initiate transcription in your liver cells?

Binds the promoter and transcription factors

Two potential devices that eukaryotic cells use to regulate transcription are

DNA methylation and histone modification.

The average length of a transcription unit along a eukaryotic DNA molecule is about 27,000 nucleotide pairs, whereas an averaged-sized protein is about 400 amino acids long. What is the best explanation for this fact?

Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that are not translated.

Identify this molecule: MTAASMGPVRAFVVLLALC

Protein; because it is an amino acid sequence (which is another way to write protein with single letters)

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called

RNA interference.

Identify this molecule: 3'-CAUGGUUCUUAUC- 5'

RNA; because there's one strand and uracil is present.

A researcher is preparing to insert a human gene of interest into a bacterial plasmid in order to clone the human gene. She has genetically engineered the plasmid to carry a gene amp R , which confers resistance to the antibiotic ampicillin. She will include ampicillin in the plating medium when she grows the recombinant bacteria. Why has she engineered the plasmid to include an antibiotic resistance gene? Choose the best answer.

Recombinant bacteria that have taken up the plasmid can be recognized because they are able to survive in the presence of ampicillin.

Assume the bottom strand is the template. Which way is the RNA Polymerase moving? 3'-ATCGGCAGGACCTTA- 5' 5'-TAGCCGTCCTGGAAT- 3'

Right to left

When the genome of a particular species is said to include 20,000 protein-coding regions, what does this imply?

There are also genes for RNAs other than mRNA.

Why are yeast cells frequently used as hosts for cloning?

They are eukaryotic cells.

Which of the following is true of embryonic stem cells but not of adult stem cells?

They can give rise to all cell types in the organism.

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the

bonding of the anticodon to the codon and the attachment of amino acids to tRNAs

In colorectal cancer, several genes must be mutated in order to contribute to a cell developing into a cancer cell, supporting Knudsen's hypothesis. Which of the following kinds of genes would you expect to be mutated?

genes involved in control of the cell cycle

Genetically engineered plants

include transgenic rice plants that can grow in water of high salinity.

Which of the following is a protein produced by a regulatory gene?

repressor

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.

A group of six students has taken samples of their own cheek cells, purified the DNA, and used a restriction enzyme known to cut at zero, one, or two sites in a particular gene of interest. Why might they be conducting such an experiment?

to find which of the students has which alleles

4. Use this representation to answer the following question. DNA template strand 5' ____________________________ 3' DNA complementary strand 3'; ____________________________ 5' In transcription event of the previous DNA, where would the promoter be located?

to the right of the template strand