IMMUNOLOGY ONLY

13. Mycobacterium tuberculosis is an intracellular bacterial pathogen. An individual’s exposure to this pathogen can be tested by injecting it into the skin. What type of reaction would you expect in an individual who had been exposed to M. tuberculosis? What is the principle behind this test?

Background:

You are a CDC (Center for Disease Control) researcher studying malaria. Your goal is to understand the evolution of malaria in order to be able to possibly predict where a future outbreak may be. To do this you will be using information from the evolution of the pathogen, the host, and changes in the environment. Topics to think about include:

• What is the evolutionary origin of human malaria? (hint: think about host-pathogen cospeciation or host shift)
  • What could you learn about the adaptability of the malaria pathogen based on its reconstructed evolutionary history?
• How does the information on the origin of human malaria affect your prediction for possible outbreaks? (hint: think what are the reservoirs for malaria pathogens)
• What would happen if changes in climate affect the distribution of the malaria mosquito vector?
  • Think if and how patterns of malaria geographic distribution would change by considering also the effect that the presence/absence of the sickle cell anemia allele would play
  • How likely is it that human populations living in a geographic area without malaria will have a high frequency of the sickle cell anemia allele?

The information that you have is:

• Knowledge of the malaria cycle, which includes one host, primate (human, chimpanzee, or gorilla), and one vector, mosquito. Malaria is prevalent in areas where the mosquitoes thrive (hot and humid).
• Access to three different pathogens: Plasmodium falciparum (host: human), P. reichenowi (host: chimpanzee), Plasmodium sp. (host: gorilla).
• The knowledge that individuals that have one (heterozygotes) or two (homozygote recessive) alleles for sickle cell are partially protected from malaria (although they still suffer some negative effects from the sickle cell disease)

Think about what type of information you would need to approach the problem above and how you would interpret different patterns. Answer the questions with a series of “if-then” scenarios in which you explore a different types of information you may get from the data and how you would interpret it.

Malaria life cycle

Question:

How would you distinguish between cospeciation and host shift (draw phylogenetic trees with the malaria pathogens and their hosts to illustrate the two scenarios)? Briefly describe and explain your phylogenies.

The WHO recommends that mothers breastfeed for a minimum of 2 years. The American Academy of Pediatrics recommends breastfeeding for only 1 year. Why do you think these recommendations are different? Apes breastfeed on average 4-6 years, how does this compare to the average breastfeeding duration in humans in our society (3 months). Do you think there may be nutritional/developmental consequences for humans?

Nutrition During Adulthood

Our goal is to live longer lives through proper nutrition, but also to maintain a quality of life for as long as possible. What does it mean to compress morbidity? How do nutritional needs change as you enter your 60s and beyond? How can you adjust your nutrition and exercise now to conserve the function of your organ systems (reserve capacity) through old age?

Fill in the blank:

When performing a negative stain, the ____________ charged proteins inside the bacterial cell will be repelled by the _____________ charged dye, thus allowing for visualization under the microscope.

When performing a simple bacterial stain, the _______________ charged proteins inside the bacterial cell will be attracted to the ____________ charged dye, thus staining the interior of the cell to allow for visualization under the microscope.

Below is a chart I'm trying to fill out for Invertebrates. I wanted to know if my answers are correct, and if you can help me fill in the sections that I didn't understand (the blank parts). Thank you!

For which of the three types of endocytosis is transcytosis a subtype? What makes this the best category of endocytosis when considering the cell types which typically use transcytosis?

1. Describe the nature of the carbon cycle, the transfer of carbon within a biological community, and how humans have impacted this very important nutrient cycle.

2. Evaluate the role that humans have played in global environmental change, with reference to five specific examples of defined impacts.

1. Interspecific interactions have evolved over many generations and been favoured by natural selection which is why these interactions persist today. Discuss this statement with reference to at least five (5) types of interspecific interactions using relevant species examples.

2. Community structure is a dynamic that is influenced by many factors. Describe and discuss the interplay of five (5) factors with reference to Pacific Island biological communities

Biology of Stem Cells:

You injected 1000 Ovarian cancer stem cells into a SCID mouse and a tumor forms. How do you determine tumorigenic potential of the cancer stem cells

A DNA strand reads 5'AATCGTAGTC3'. The adjacent strand should read:

3'AATCGTAGTC5'

3'TTAGCATCAG5'

5'TTAGCATCAG3'

None of the above

All of the above

Regarding protective geochemical barriers:

1) Definition

2) Goal and principle of biogeochemical barrier

3) Goal and principle of chemically reacting barrier

4) Please list groups of the anaerobic bacteria involved in creation of biogeochemical barriers and describe their roles.

5) Mention potential advantages and disadvantages of the geochemical barriers compared with other bioremediation technologies as far as you know.

Biology of Stem Cells:Thanks!

1a: A miRNA regulates its target mRNA by degradation. Let’s assume miRNA-199 targets Blimp1. Which progenitor population in the developing embryo will be affected?

1b:How does this affect your ability to isolate this progenitor pool?

How would you prepare the following solutions? Unless stated otherwise, assume that the solvent is purified water and that you will dissolve the solute in a lesser amount of solvent and then “bring the solution to volume”

CuSO₄ FW 159.61

NaCl FW 58.44

CaCl FW 111.0

Na₂SO₄^. 10H₂O FW 322.04

1. 100 ml of AgNO₃ at 2 g/ml

2. 250 ml of NaCl at 2 mg/ml

3. 0.75 L of CuSO₄ at 50mg/ml

4. 250 ml KCl at 20 mg/ml

5. 50 ml of 0.1% (w/v) AgNO₃

6. 500 ml of 1%( w/v) NaCl

7. 10 ml of 6% (w/v) CuSO₄

8. 200 ml of 2% (w/v) KCl

9. 25ml of 20% (v/v) Methanol

10. 2L of 70% (v/v) Ethanol

11. 10 ml of 0.2% (v/v) DMSO

12. 50 ml of 3% (v/v) Propanol

13. 250 ml 12 mM CuSO4

14. 500 ml 0.25M NaCl

15. 500 ml 25mM CaCl

16. 100 ml 300 mM Na₂SO₄

17.100 ml of 5:3:2 ethylene: chloroform: isoamyl alcohol

18. Convert 50 ppm to g/L

19. Convert 50 ppm to mg/L

20. Convert 5 ppb to ul/l

21. Convert 3 ppm to l/ml

22. Convert 350 ppm to ml/L

23. 300 ppb Cadmium (solid)

Explain why the (Na⁺-K⁺)-ATPase carries out transport in one direction only.