Answer:
B
Explanation:
I took the test on A P E X. I hope I'm not to late for the answer!
The Griffith's experiment, the Avery-MacLeod-McCarty experiment, and the Hershey–Chase experiments were the set of experiments that established DNA as the key hereditary molecule. The Avery-MacLeod-McCarty experiment was an extension to the Griffith's experiment. The heat killed virulent S strain cells of the Griffith's experiment were lysed to form a supernatant containing a mix of RNA, DNA, proteins and lipids from the cell. The supernatent was equally divided into 3 parts after the removal of the lipids. The 3 parts were respectively treated with an RNAase to degrade the RNA, DNAase to degrade the DNA and proteinase to degrade the proteins. The treated supernatant was then added into the culture containing the non-virulent R cells. In case of the supernatant treated with the DNAse, no transformation of R cells into S cells occurred. The transformation of R cells to S cells occurred in the proteinase and the RNAse cases. This indicated that DNA was the hereditary molecule and not protein or RNA.
Answer:
Aspirin works by inhibiting the production of prostaglandins. Aspirin inhibits the formation of prostaglandins by combining with the COX enzymes. Prostaglandins function as messenger molecules to monitor different physiological procedures in distinct regions of the body. One of the prime activities of prostaglandins is to stimulate inflammation and pain.
Prostaglandins are also the essential controller of platelet aggregation. By changing the COX enzymes inside the platelets, aspirin makes platelets to lose the stickiness, which is required to instigate clotting of blood.
There are two forms of cyclooxygenase, that is, COX-1 and COX-2. COX-1 generates prostaglandins and COX-2 mediates pain and swelling in response to tissue injury. Aspirin prevents both COX-1 and COX-2 functioning, while COX-2 is the therapeutic target of the drug.
However, it is the association of aspirin with COX-1 in the gastrointestinal tract, which results in the unwanted side effects of the drug. COX-1 is required to sustain a thick lining of the stomach. As aspirin inhibits the COX-1 enzyme, thus, the continuous use of the drug can result in the thinning of mucus, which safeguards the stomach from gastric juices.
In such cases, stomach bleeding, ulcers, and in certain situations perforation of the stomach can take place. Therefore, aspirin exhibits both bad and good effects.
