Question

1. Explain why a cut or scraped kneed increases the chance that pathogens will trigger an immune response.
2. Since a fever is a protective mechanism, should we avoid taking aspirin?
3. Humans (and all other organisms) are in an evolutionary battle with a wide variety of pathogens. How does natural selection favor pathogens that evade the immune system?
4. How do vaccines work to protect you from disease?
5. What advantage does sexual reproduction provide for a species?

Answer 1

Inflammation is the normal response of immune system to injuries and harmful things that enter your body. Immune cells quickly react to the damaged area to fix the problem.
Swelling is a normal reaction of the body to an injury. Sometimes the body goes overboard and the swelling response is excessive.
When injury takes place, the physical barrier, skin and blood vessels and epidermal tissues are opened, which will increase the chances of infection.

Aspirin, is also known as acetylsalicylic acid (ASA). It is a medication used to treat pain, fever, or inflammation.
fever is a potentially harmful consequence of infection, so one should suppress it to minimize its complications. Otherwise due to the rise in the temperature, there will be denaturation of enzymes, which will result in the physiological functions of the body. So, Aspirin has to be used to control the fever.
true pathogen is an infectious agent that causes disease in virtually any susceptible host. Or the microbes that could evade the immune system can survive successfully and reproduce as per the natural selection. If they can't evade they can't survive, so as per the survival of fittest of natural selection, those microbes which are fittest could only survive and remaining will die.
Vaccines mimic original pathogenic microbe and thus, they boost the immune response before the actual entry of pathogenic microbes, since vaccines are the attenuated or killed pathogenic strains that administered into the human body to boost the immune system.
Sexual reproduction maximizes the successful variations, with which survival chances of the Organisms under unfavorable conditions will be improvised.