topic: adolescent use of protective measures to prevent dental caries in their permanent teeth

Briefly explain how the scientific method could be used to address one issue related to the topic above.

How do the four levels of protein structure affect the shape of enzymes and why is this important for enzyme function? Explain the "lock and key" model of enzyme function using the terms substrate, active site, and product.

1) What is the event that marks the transition from haploid to the diploid stage of the life cycle and what event marks the transition back to the haploid stage again. Describe the timing of these two cellular even in life cycles that are dominated by haploid cells, dominated by diploid cells or that have alternation of generations.

2) What are the closest relatives of land plants? How do you know this? What do these relatives tell us about the ancestors of green plants -- where did they live? How big were they?

3) Why was it the green algae that gave rise to land plants -- why don’t we have relatives of red or brown algae living on land?

“In the model organism E. coli, recombination mediated by the related XerC and XerD recombinases complexed with the FtsK translocase at specialized dif sites, resolves dimeric chromosomes into free monomers to allow efficient chromosome segregation at cell division. Computational genome analysis of Helicobacter pylori, a slow growing gastric pathogen, identified just one chromosomal xer gene (xerH) and its cognate dif site (difH). Here we show that recombination between directly repeated difH sites requires XerH, FtsK but not XerT, the TnPZ transposon associated recombinase. xerH inactivation was not lethal, but resulted in increased DNA per cell, suggesting defective chromosome segregation. The xerH mutant also failed to colonize mice, and was more susceptible to UV and ciprofloxacin, which induce DNA breakage, and thereby recombination and chromosome dimer formation. xerH inactivation and overexpression each led to a DNA segregation defect, suggesting a role for Xer recombination in regulation of replication. In addition to chromosome dimer resolution and based on the absence of genes for topoisomerase IV (parC, parE) in H. pylori, we speculate that XerH may contribute to chromosome decatenation, although possible involvement of H. pylori's DNA gyrase and topoisomerase III homologue are also considered. Further analyses of this system should contribute to general understanding of and possibly therapy development for H. pylori, which causes peptic ulcers and gastric cancer; for the closely related, diarrheagenic Campylobacter species; and for unrelated slow growing pathogens that lack topoisomerase IV, such as Mycobacterium tuberculosis.”

article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC332523

What is one intrinsic problem with circular DNA molecules during homologous recombination? How does this effect cell division?

Bacteria with circular chromosomes typically contain site-specific tyrosine Xer recombinases and dif sites. Why are these recombinases and dif sites important to the bacterial cell?

Briefly explain how the XerC and XerD recombinases function in E.coli.

How does the H.pylori Xer recombinase system differ from the E.coli system? How is it similar?

E.coli typically removes topological links between concatenated DNA by using topoisomerase IV. H. pylori seems to lack topoisomerase IV. If this is the case, how does H. pylori deal with circular DNA dimers and/or multimers?

One of your friends is preparing for a run in a marathon. She has heard about eating a pasta dinner to glycogen load the evening prior to the marathon. Explain in biochemical terms what glycogen loading is and how it works? Please include hormonal controls, key enzymes and a discussion of both liver and muscle in the process.

For ATP synthesis by oxidative phosphorylation, the P/O ratios of NADH and FADH2 are ~2.5 and ~1.5, respectively. Explain how mitochondrial electron transport, ATP synthase, and other membrane processes account for these numbers?

List and describe the derived traits of plants.

Quantification of DNA Using Agarose Gels

Directions: Please answer the following questions in complete sentences.

What problems might arise if the agarose wasn't dissolved/melted completely or if there were air bubbles in the gel?

Why did your DNA samples need to be mixed with a loading dye prior to loading the samples into the gel? Give 2 reasons.

What causes the DNA to travel through the gel?

Draw a sketch of what your gel would have looked like (after 5 minutes) if you reversed the positive and negative leads and placed the positive lead closest to the wells. Label the positive and negative leads, the wells, and the DNA.

Why do smaller DNA fragments travel further down the gel?

1.What is a Great evolutionary transformation?

2. Why is the evolution of whales puzzling?

3. What was Darwin's hypothesis about whale evolution?

Flowers are sometimes referred to as ‘pets of the plant world’. Explain this statement. How did alliance with humankind affect the evolution of plants cultivated for their flowers?

Use a flow chart or draw a picture to describe how fusion peptides works. Using HIV as an example, describe the proteins involved and where the process occurs. Be sure to identify what "trigger" HIV senses that initiates membrane fusion.

Advances in genetic technology like genetic and genomic testing and gene editing are transforming human biological sciences, but are creating new ethical dilemmas. Here, we address the implications of direct-to-consumer genetic testing.

**Note--link to NPR story below is now functional
FDA Approves Marketing of Consumer Genetic Tests (NPR, 4/7/17) (Links to an external site https://www.npr.org/sections/health-shots/2017/04/07/522897473/fda-approves-marketing-of-consumer-genetic-tests-for-some-conditions

I had My DNA Picture Taken, With Varying Results (New York Times, 12/30/13) (Links to an external site. http://www.nytimes.com/2013/12/31/science/i-had-my-dna-picture-taken-with-varying-results.html

Read the two articles (links below) and then address the following questions in your post.

Would you be interested in having such a genetic test done? Why or why not? If you have had a consumer DNA test done and would like to share your experiences, you are welcome to do so.

Would you want to know if you were destined to contract an incurable degenerative disease such as Huntington's disease or Alzheimer's later in life? Would the results of such a test cause you to alter your lifestyle?

What concerns (with regard to ethics, privacy, etc.) might arise with the widespread use of such tests?