Question

1. Deep sea thermal vents are characterized by extremepressures, very high water temp (exceeding 100 celsius) and veryhigh concentrations of minerals. What type of prokaryotic organismsare most likely to be found there and why?

Archaea; tetraethers are morethermally stable.

Archaea; the partial membranessurrounding the DNA provide more protection.

Bacteria; the peptidoglycans in thecell walls keep them from overheating.

Bacteria; they use the energy from the minerals to power theirchloroplasts.

2. Farmers often practice crop rotation to help enrichagricultural fields. Why are beans and other legumes often used inthe rotations?

Legumes remove toxins from thesoil.

Less carbon dioxide.

Bacteria in legume root nodules arenitrifiers.

Legumes enrich the soil by formingheterocysts.

Beans fix nitrogen.

3. The fungus Penicillium produces a compound thatblocks peptidoglycan assembly. Why is a fungus trying to killbacteria?

The compound produced by the fungusis used for nitrogen fixation, the antibacterial properties areaccidental.

The fungal compound is produced inresponse to a bacterial invasion of the fungal hyphae.

Fungi and bacteria are bothdecomposers and compete for resources.

Fungi eat bacteria.

4. If Chlamydia is often asymptomatic, why is it necessary totreat it?

Pelvic inflammatory disease is apotential complication and can render women sterile.

Tertiary chlamydia causesneurological problems.

Chlamydia infection is a major riskfactor for cervical cancer.

Vertical transmission of chlamydia causes birth defects.

5. A mutant strain and the wild-type have different growthrequirements, they are given below.

Wild-type growth factors: A,B,C,D
Mutant growth factors: A,B,C,D,E

Select all the true statements concerning this situation.

It is possible to formulate a mediathat will allow the mutant to grow but not the wild-type.

A minimal medium will allow themutant to grow.

The mutant is auxotrophic.

Replica plating would be used toidentify the mutant.

An early stop codon may have occurred in the mutant.

6. Cell X has 45% adenine in it's genome and a thickpeptidoglycan cell wall. It is most likely a(n)

cyanobacteria

fungal endospore

low CG Bacteria

thermophilic archaean

actinobacteria

7. Are transformation and transduction the same process?

No; only transformation passes ongenes for pathogenicity.

Yes; they both involve theacquisition of viral genes.

Yes; both processes transferspecific gene products to a specific bacterium.

No; although both involve gene transfer the sources of thegenetic material differ.

8. In terrestrial environments, nitrogen fixation only occurs insoils. Why is this the case?

	Free oxygen acts and atranscription inhibitor of nif genes.
	The enzymatic activity of thenitrogenase complex is inhibited by oxygen.
	UV-radiation denatures thenitogenase enzyme complex.
	nif genes are sensitive tolight.