the following are the initial steps involved in aseptic transfer to an agar plate. place them In their proper order.(a,b.c,d?)

1. Flame loop

2.insert loop into broth & touch to plate

3. mix tube

a)3,4,2,1

b)3,1,4,2,1

c)1,2,3,4,1

d)4,3,2,1

4) flame tube

1) A bacterial strain called XYZ living in the lake MBG223 near Bilkent University requires to synthesize tryptophan continuously. The reason is, the essential proteins (essential means, the proteins required for survival of the bacteria) contain high content of tryptophan. Therefore, this bacterial strain XYZ has a tryptophan operon. Unfortunately, the tryptophan level of nutrition available in lake MBG223 is very limited during summer and winter time and the other nutrition levels are high. During the summer time, as the lake MBG223 partially evaporates, the salinity of the water increases, the temperature of the lake arises and the pH of the environment turns from natural to acidic. Changes in salinity, pH and temperature is known to disrupt hydrogen bonding in nucleotide base-pairings and also the structure of the proteins. Here, assuming that the structure/function of the proteins are not effected please answer the following.

İnside the XYZ bacteria, what would you observe with regards to synthesis of tryptophan bearing proteins during summer vs. winter time? How would this effect bacterial growth rate during the summer time vs winter time?

2)In another neighboring lake called MBG222, they found a different bacterial strain called WOWWW to have mutant tRNAs on the anti-codon region of the tRNA. This tRNA carries Phenylalanine to wherever it encounters the sequence UGG (tryptophan) on the mRNA. What happens to the regulation of the trypthophan operon in bacteria that has 1) high tryptophan and low phenylalanine vs. bacteria that has low tryptophan and high phenylalanine?

1. Please describe an “age pyramid” for the baby boom generation? Why is the shape of this pyramid so important for future generations to contemplate? (3 points)

Scenario
Doug was a newly single 42-year-old man, whose reentry into the dating world led to a few casual sexual encounters with women he met while out in bars.

After 8 months apart, Doug and his wife reconciled. He decided it would be best not to mention the other women he had intercourse with because he was pretty sure his wife would get upset even though they were not together at the time.

Signs and symptoms
Several months later, during a dentist’s appointment, the hygienist noted what looked like a series of small bumps on the back and side of Doug’s tongue, which had not been noted in his chart before.

At his next visit, the bumps had expanded into lesions and Doug mentioned them as a concern. The dentist noticed that his tonsil on the side of the tongue lesions was swollen, as were the lymph nodes. He prescribed an antibiotic, which Doug took.

The lesions didn’t get better but they also got no worse. A few weeks later Doug developed a stubborn sore throat, so he went to see his family physician.

Testing
When Doug’s doctor saw the lesion at the back of his tongue, he sent Doug for an oral brush biopsy procedure.

When the biopsied tissue was stained with hematoxylin and eosin stain, the pathologist noted a well-differentiated squamous cell carcinoma.

A second sample was obtained by scalpel biopsy and tested for human papillomavirus (HPV) DNA, specifically HPV-16 and HPV-18. The results were returned as positive for viral DNA.

Question 1: Referring to the image below obtained by transmission electron microscopy (TEM), describe the following characteristics of HPV: Enveloped or nonenveloped? Capsid symmetry?

Question 2: HPV has a double-stranded DNA genome. What is the Baltimore group for HPV?

Question 3: Other than genome, what criteria are used in the Baltimore model to create distinct groups of viruses?

Diagnosis
Doug’s diagnosis was stage IV squamous cell carcinoma.



Question 4: How is the detection of HPV DNA in the cancer tissue pertinent to this diagnosis?

Question 5: How does HPV facilitate the replication of its genome and production of mRNA transcripts from the viral genes?

Treatment
Doug had surgery to remove the cancerous tissue, followed by six months of radiation therapy. After two years, there was no recurrence of the cancer.

Question 6: A vaccine, Gardisil, is available to prevent HPV infection. How does a vaccine that protects against a viral infection prevent cancer?

Additional Considerations
Question 7: In a human host cell, where does the process of viral DNA replication occur?

Question 8: Where does translation of HPV mRNA occur in an infected host cell?

Question 9: How are viral latency and lysogeny related?

A)How is the lac operon regulated if the bacteria is put into an environment where there is excess amount of lactose and glucose at the same time. (10 pts)

B)From the previous question, how would the outcome change if the glucose and lactose amounts are very low? (10 pts)

C)Where would the lac repressor be bound in E. Coli bacteria that is growing in low glucose and high lactose? (7pts)

What items do photosynthesis and cellular respiration have in common? For example:

Item: Produce ATP

Photosynthesis: light reactions

Cellular Respiration: Glycolysis, Krebs Cycle, Electron Transport

1. Upregulation of what surface receptor allows a mature thymocyte to leave the thymus? (explain in depth)

Compare and contrast how lipid soluble and amino-acid derived hormone signaling can control gene expression. At what level do they control gene expression? How do they control it? In your answer, be sure to explain: the flow of information from DNA to protein to describe how a gene is expressed and made into its protein product. Also the differences between receptors for amino acid-derived hormones and lipid soluble hormone

4. What four cells make up the pollen grain in Conifers?

5. Are coniferous sperm flagellated?

6. Where does fertilization occur and what structure becomes a seed in pine trees?

7. Explain double fertilization

8. Name the structures that precede the ones listed in the life cycle of a seed plant.

1. ____________ Female gametophyte

2. ____________ Male gametophyte

c. _____________ Adult sporophyte

9. What are the three parts of a seed in angiosperm

10. Compare conifers to flowering plants by completing the following table:

11. Compare the location of the ovule in the pine and the flowering plant.

12. What is the difference between pollination and fertilization?

1a) what is the relationship between substrate concentration and reaction rate?

b) Describe how the enzyme structure is effected:

1. i) below the optimal temperature

ii)above the optimal temperature?  

c)Why is enzyme activity reduced at pH values above or below the optimum? How does the enzyme structure change at non-optimum pH?

Based on the symptoms and virulence of each of these diseases, indicate for each disease whether there is a stronger selection for competition within hosts or stronger selection for movement across hosts. Defend your conclusion for each disease and list the major symptoms of each disease.

1.Tuberculosis

2.Covid-19

3.Ebola

List nine traits that developed during human evolution. Two species that have each trait (you can't use the same species twice so it must be two new species for each trait) and approximately in millions of years when these adaptations took place.