DOC PREVIEW
UIC BIOS 100 - BIOS 100, Cells and Organisms Exam III

This preview shows page 1-2-3 out of 8 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

-1-BIOS 100, Cells and Organisms Name:Exam III, 6 November, 2009Michael Muller, InstructorThis exam consists of 42 very simple questions lovingly dispersed over the following eightpages. Last exam I threatened to take away points for not bubbling in your last name first, and noone lost points! Woohoo! I was truly happy with this! If everyone can do this again, I will giveeveryone some bonus points. But EVERYONE has to do it, so don’t blow it for the class...1. What would be the level of gene expression in the lac operon if the operator were mutated sothat the repressor protein could no longer bind to it?A. The lac operon would be permanently shut offB. The lac operon would be permanently turned on with frequent transcriptionC. The level of transcription of the lac operon would depend upon the concentration ofglucoseD. None of the above 2. A second mutated strand of E. coli was created. In this mutant, the gene which makes therepressor protein was damaged and could no longer produce a functional repressorprotein. Johnny the lab tech accidentally mixed up the cultures of this mutant with themutant described in question #1. Based solely on the patterns of expression of the lacoperon, how could Johnny separate these two cultures?A. Johnny would separate them because the operon in one of the cultures is always goingto be turned off while the other culture will always be expressing the lac operonwith frequent transcriptionB. Johnny would separate them because the operon in one of the cultures is always beexpressing the lac operon with frequent transcription while the other culture hasexpression which depends on the level of glucoseC. Johnny would separate them because the operon in one of the cultures is always goingto be turned off while the other will have expression which depends on the levelof glucoseD. Johnny will not be able to separate them based on the patterns of expression of the lacoperon. Johnny needs to look for a new job...Use the following information of the L-arabinose operon to answer questions 3-4.The L-arabinose operon is an operon which produces enzymes to break down themonosaccharide sugar arabinose into D-xylulose-5-phosphate. If arabinose is present, it willbind to a protein called AraC to form a complex (called AraC-arabinose). The binding of thiscomplex to an operator is needed for RNA polymerase to bind to the promoter and transcribe theoperon. Additionally, a second compound of CAP + cyclic AMP must bind to the DNA to fullyinitiate transcription of the L-arabinose operon. There is infrequent transcription without thisCAP + cyclic AMP compound bound to the DNA. 3. The L-arabinose operon is ______________.A. Inducible B. Repressible C. Not enough information to determine4. If arabinose and glucose are present, would you expect the L-arabinose operon to be on withfrequent transcription?A. Yes B. No C. Not enough information to determine-2-5. IPTG (Isopropyl â-D-1-thiogalactopyranoside) is a chemical which can bind to the allostericsite of the repressor protein of the lac operon and cause the same conformation change aslactose. IPTG is not broken down by â-galactosidase (or any other enzyme relative to thisproblem). You have two E. coli cultures with fully functional lac operons. In one cultureyou add lactose and in the second you add an equivalent amount of IPTG. A highconcentration of glucose is present in both cultures which will remain high throughout theduration of your observations. What would you expect to be the level of gene expressionin both cultures?A. Both cultures have continuous expression of the lac operon for a very long time.B. Both cultures have initial expression of the lac operon, but expression in the lactose-added culture ends while expression of the IPTG-added culture is continuous.C. Both cultures have initial expression of the lac operon, but expression in the IPTG-added culture ends while expression of the lactose-added culture is continuousD. Both cultures have initial expression of the lac operon, but expression in both culturessoon endsE. There is no expression in either the IPTG-added or lactose-added cultures6. Immediately after mitosis, you introduced a chemical which destroyed the histone-acetylcomplexes (HATs) in an eukaryotic cell. What will be the effect on gene expression inthis cell?A. All gene expression will be affected and the cell will most likely dieB. Gene expression will be slowed down, but most genes should still be able to beexpressed in a limited capacityC. The expression of genes affecting mitosis will be affected; it will have minimalimpact on other genesD. There will be no noticeable affect on gene expressionE. Not enough information to properly determine the effect on gene expression 7. What would happen if there was a mutation in the TATA box of the gene which makes asubunit of hemoglobin which changed sequence of the TATA box from TATAAAA toGCGCGCCC?A. All gene expression in the cell would be affected and the cell would dieB. TFIID would be unable to bind to the basal promoter and the gene would not beexpressedC. TFIID would be unable to bind to the basal promoter, but transcription of the genewould still occur, albeit at a lower frequencyD. Expression of this gene would be unaffected.E. Not enough information to determine the effects of this mutation on gene expression8. Johnny the lab tech took a new job in another molecular biology lab. He got bored, so he wasplaying around with the genetic code of a yeast (which is an eukaryote, shame on you ifyou didn’t know that). He removed an enhancer region of the gene to make the othersubunit of hemoglobin and moved it a thousand base pairs away from its originallocation. What effect will this have on expression of this gene?A. All gene expression in the cell will be affected and the cell will dieB. The relocation of the enhancer will prevent this gene from being expressedC. The relocation of the enhancer will greatly slow down the rate of transcription of this geneD. The relocation will have no noticeable effect on the rate of transcription of this gene-3-E. Not enough information to determine the effects of this relocation on gene expression9. Johnny had to come up with a senior research proposal. He was doing research onspliceosomes in mice, but he really hates working with mice, so he wrote up a proposal todo similar research on the spliceosomes in E. coli bacteria. Why will Johnny’s


View Full Document

UIC BIOS 100 - BIOS 100, Cells and Organisms Exam III

Download BIOS 100, Cells and Organisms Exam III
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view BIOS 100, Cells and Organisms Exam III and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view BIOS 100, Cells and Organisms Exam III 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?