In certain organisms, exposure to a toxin leads to resistance as a result of mutation of the toxin receptor. At the same time, reproductive ability is lost. Explain how a change in the expression of a gene for a toxin receptor could also affect expression of a gene needed for reproduction.

OneClass: In certain organisms, exposure to a toxin leads to resistance as a result of mutation of th...

1- A new beetle species has arrived in Ohio and ate the wheat, destroying much of the harvest. Research in lab has found that a toxin from the bacterial species Bacillius subtilius can kill the beetle when ingested. You are able to make recombinant DNA containing a plant expression vector and the toxin gene from Bacillius subtiliu. This toxin gene is transcribed and translated in plant cells in the lab. Before introducing this recombinant DNA into corn plants, what main concern do you need to first address?

A) Do we have the technology to express the toxin in this plant cell?

B) Will this gene escape the corn plant and the DNA inserts itself into other plant species?

C) Will the toxin harm humans/livestock when they eat the corn?

D) Will introfuction of the recombinant DNA select for naturally resistent weeds?

E) other

2- You are working on influenza virus infection and want to know if the isg15 gene in mice protects against a particular iinfluenza viru strain? You ask if the isg15 decreases influenza viral replication. You want to silence the expression of the isg15 gene in cells, and you only need the gene silence for a short time (24-48hours). What is the fastest method you would use to silence the isg15 gene?

A) Polymerase chain reaction (PCR) for the isg15 gene

B) Make a ecombinant DNA molecule conyaining the isg15 gene that can be expressed in mouse cells

C) Use homologous recombination to knock out the isg15 gene and then grow up those cells

D) Use a short interfering (si)RNA to the isg15 gene

E) Use a microarray to look at the isg15 levels

3- A mutation in the TATA box would:

A) allow more transcription factors to bind to the DNA

B) prevent RNA polymerase from bindng to the DNA

C) prevent alternative spilcing

D) Mutate the silencer sequence of the DNA

E) Allow RNA polymerase to start transcription

4- If a genes template strand's DNA sequence is 3'-TGA-5', the codon sequence is ___ and the anticodon sequence is ___.

A) 5'-ACU-3' and 3'-UGA-5'

B) 5'-ACT-3' and 3'-TGA-5'

C)5'-UGA-3' and 3'-ACU-5'

D)5'-ACU-3' and 3'-ACU-5'

E)5'-UGA-3' and 3'-UGA-5'

Please help and explain why! Thanks!!

A certain mutation in the receptor for epidermal growth factor (EGF) causes the mutated receptor protein to send a positive signal along the associated intracellular signaling pathway even when the EGF ligand is not bound to it. This signal leads to abnormal cell proliferation in the absence of growth factor. On the basis of this information, would you class the gene for the EGF receptor as a tumor suppressor gene or a potential oncogene? Explain your answer.

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Part A

The ultimate problem with cholera that can lead to death is __________.

only water loss

fluid loss with electrolyte concentrations remaining normal

severe dehydration and electrolyte imbalance

only electrolyte loss

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Part B

The loss of chloride ions is occurring as a result of an continuously open __________, found in certain intestinal epithelial cells.

chloride channel protein

sodium pump

ATP dependent sodium/potassium pump

potassium pump

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Part C

The main purpose of the chloride channel proteins on the apical surface of the intestinal epithelial cells is to create an osmotic gradient that ultimately causes __________ to move through the intestinal epithelium and into the intestinal lumen to assist in the formation of mucus. These are the same chloride channel proteins, adversely affected in cystic fibrosis.

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Part D

The main physiologic mechanism used to control the opening of the chloride channel protein is through the use of __________.

G proteinâlinked receptors

potassium pump

enzyme-linked receptors

sodium pump

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Part E

The main factor that causes cholera is the overstimulation of __________ by the __________.

guanylate cyclase; the bacterium Vibrio cholerae

adenylate cyclase; the bacterium Vibrio cholerae

guanylate cyclase; cholera toxin

adenylate cyclase; cholera toxin

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Part F

The normal physiologic mechanism used by G proteinâlinked receptors is for a ligand to bind to the G proteinâlinked receptor; this in turn activates __________ located in the intracellular side of the plasma membrane, which eventually leads to the physiologic effector action.

diacylglycerol

inositol triphosphate

G protein

cyclic AMP

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Part G

Cholera toxin bypasses the normal sequential cascade of events involving G protein activation. The __________subunit of cholera toxin enters into the cell and directly activates __________. This leads to a non-physiologic (non-homeostatic) action of inappropriately maintaining the chloride channel proteins open. This causes excessive __________, sodium, and water to leave the intestinal epithelial cells.

A; G protein; chloride

B; G protein; chloride

B; inositol triphosphate; calcium

A; diacylglycerol; chloride

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Part H

A defect in the chloride channel protein, causing it to not open, will _________ the chloride, sodium, and water loss in cholera. However, it will also cause the individual to have __________ mucus.

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Part I

A drug that prevents the cholera toxin from attaching to the __________ in the intestinal epithelial cell could be a useful treatment.

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