A complementary medicine company is interested in determining if herbal extracts can improve the efficiency of antibiotics at low concentrations. Design an experiment to determine if Echinacea diluted 1:100 can increase the effectiveness of ampicillin against E. coli when tested at 10% of the minimum inhibitory concentration of ampicillin.

Avoparcin, a glycopeptide antibiotic, was widely used in animal feed in Denmark. Vancomycin is another glycopeptide. In 1995, the percent of vancomycin-resistance Enterococcus faecalis (VRE) isolated from pigs was 100. The use of avoparcin was banned in Denmark in 1995. In 2002, Danish scientists reported that 20% of their E. faecalis isolates was vancomycin resistant. Explain why the percent of VRE decreased and why VRE in pigs is important to humans.

How could operon fusions and gene fusions be used to determine the level of transcription and translation of a particular gene?

1. In a tube of Thioglycollate broth, _ would grow at the very top portion of the tube while ___ would grow throughout the tube.

B. Obligate anaerobes, obligate aerobes

C. Microaerophiles, facultative anaerobes

D. Obligate aerobes, facultative anaerobes

2. Which of the following does acheive sterilization?

A. freezing

B. boiling

C, ethylene oxide

D. none of the above

3. All of the following are modes of action of antiviral drugs except __

A. inhibition of peptidoglycan synthesis

b. inhibition of DNA or RNA synthesis

C. inhibition of fusion

d. inhibition of uncoating

4. The beta-lactams affect the crosslinking between NAM subunits. How are we able to use these drugs against bacteria and not do significant harm to our own cells?

a. Human cells use 80S ribosomes, while bacteria use 70S ribosomes.

b. Human cells do not possess peptidoglycan.

c. Human cells have different cell membranes than bacteria.

5. Tamiflu works against the influenza virus by blocking the action of neuraminidase, thereby blocking ____ of the virus.

A. attachment

b. biosynthesis

c. release

6. Mary is put on antibiotic treatment for an infection. After a week, she develops thrush, a yeast infection on the tongue. This represents which of the following?

A. synergism

b. superinfection

c. double whammy syndrome

7.  Which letter represents the phase of the growth curve where the maximum population density is the greatest? Choose the answer that has BOTH the letter and the description correct.

1 A: lag phase

3. C: stationary phase

4. B. stationary phase

Describe similarities and/or differences between the phases and outcomes of mitosis and meiosis.

a. Mitosis vs. meiosis

b.Chromosome number in all stages

Giving examples, discuss how dentition varies between orders of mammals. Include in your answer a description of how teeth have become specialised to cope with insectivorous, carnivorous and herbivorous diets (400 words no plagiarism)

the majority of down syndrome cases are a result of maternal gamete carrying an abnormal number of chromosomes

Question 1

What post-translational modification will cause the biggest increase in the size of a protein, immediately when added?

Select one:

a. Phosphorylation

b. Ubiquitination

c. Acetylation

d. Methylation

Question 2

What does HMT do?

Select one:

a. It acts as an epigenator

b. It modifies nitrogenous bases

c. It produces euchromatin

d. It modifies histones

Question 3

Where can an epigenetic maintainer act?

Select one:

a. On the sequence of nucleotides

b. On the sequence of nucleotides and on the nucleotides directly

c. On certain nucleotides and amino acids

d. On certain amino acids

e. On certain nucleotides

Question 4

Which of the following types of protein could be coded by a tumour-suppressor gene?

Select one:

a. A protein that stimulate progression through the cell cycle.

b. A protein that forms part of a growth factor signaling pathway.

c. A protein that codes for a DNA repair enzyme.

d. A protein that helps prevent apoptosis.

e. A protein that repairs lost telomeres

Question 5

Which is NOT a typical mechanism by which a proto-oncogene is converted to an oncogene?

Select one:

a. A point mutation in the proto-oncogene

b. A chromosomal translocation resulting in the up-regulation of the proto-oncogene

c. Duplication of a chromosome region containing a proto-oncogene

d. Complete deletion of the proto-oncogene

e. Amplification of the proto-oncogene

Question 6

Why do you think familial retinoblastoma and Li-Fraumeni are considered to be inherited as autosomal dominant traits when the responsible genes are recessive?

Select one:

a. They are expressed in a dominant fashion in males, but recessive in females.       

b. People with this mutation are always homozygous for this allele.

c. If you are born with one allele mutated in every cell, the chance that the other allele will be mutated in one of the retinal cells is extremely high.

d. This recessive gene needs only one copy to express this phenotype.

e. Retinoblastoma was mischaracterized originally when it was called an autosomal dominant trait.

Question 7

Question text

In a normal cell, pRB binds to __________, which inhibits cell division. In the presence of __________ pRB becomes __________, which leads to cell division.

Select one:

a. cyclin+Cdk; oncogenes; dephosphorylated

b. transcription factors; cyclin+Cdk; phosphorylated

c. tumor suppressor; p53; phosphorylated

d. p21; p53; dephosphorylated

e. tumor suppressor; p21; hyperactive

Question 8

The following information relates to the next three questions:

A few decades ago, Knudsen and colleagues proposed a theory that, for a normal cell to become a cancer cell, a minimum of two genetic changes had to occur in that cell. Knudsen was studying retinoblastoma, a childhood cancer of the eye.

Two children are born from the same parents. Child one inherits a predisposition to retinoblastoma (one of the mutations) and child two does not. However, both children develop the retinoblastoma. Which of the following would you expect?

Select one:

a. a history of exposure to mutagens in child one but not in child two

b. increased levels of apoptosis in both children

c. an earlier age of onset in child one

d. decreased levels of DNA repair in child one

e. a more severe cancer in child one

Question 9

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

Select one:

a. genes that are especially susceptible to mutation

b. the same genes that Knudsen identified as associated with retinoblastoma

c. genes coding for enzymes that act in the colon

d. the genes of the bacteria that are abundant in the colon

e. genes encoding transcription factors that regulate cyclin production

Question 10

Knudsen and colleagues also noted that persons with hereditary retinoblastoma that had been treated successfully lived on but then had a higher frequency of developing osteosarcomas (bone cancers) later in life. This provided further evidence of their theory because:

Select one:

a. osteosarcoma cells express the same genes as retinal cells.

b. one of the mutations involved in retinoblastoma is also one of the changes involved in osteosarcoma.

c. p53 gene mutations are common to both tumours.

d. retinoblastoma is a prerequisite for the formation of osteosarcoma later in life.

e. both kinds of cancer involve uncontrolled proliferation of cells.

1. the number of new virions released from each bacterium host cell represent the _______.

2. "phage" attacks and multiple in __________.

3. Freezing and drying for long term storage is known as ________. (hint! coffee is preserved that way as well).

4. the organelle _______ found in certain fungi, plugs the pores of hyphal cells to prevent materials from adjacent damaged cells to move to the healthy cell.

5. those hyphae responsible for anchoring the fungus into the substratum are known as ________.

6. the stage (in viral replication cycle) which assembly of newly synthesized viral components into complete virions is called ________.

We are moving towards "eugenics." What is "eugenics" and what should we consider a defect and so a trait to be eliminated?

What would be a portion size per serving for this menu for a preschooler (3 year-old toddler): rice, pinto beans, chopped tomatoes, yoghurt.

What do the R_f values indicate about the relative solubilites of the pigments in the water and solvent phases?

Explain the relative solublities of chl b and chl a in the water and solvent phases on the basis of molecular structure.

Explain the relative solublities of b-carotene, lutein, and violaxanthin in the water and solvent phases on the basis of molecular structure.