When someone is exposed to poison ivy, the effects are not i…

When someone is exposed to poison ivy, the effects are not immediate. The characteristic rash, redness, and swelling appear up to days after exposure. (a) Why does poison ivy exposure elicit a delayed hypersensitivity response? (b) Contrast Type I and Type IV hypersensitivity reactions. (Your answer should describe differences between these types of reactions)

The human immune system defends against a wide variety of pa…

The human immune system defends against a wide variety of pathogens. Unicellular pathogens can be classified as intracellular or extracellular, and the immune system must target these two types of pathogens differently. (a) Contrast intracellular and extracellular infections and the pathogens that cause them. Describe key differences. (b) Contrast the innate immune system response to intracellular and extracellular infections and the pathogens that cause them. Describe key differences.

HIV is a formidable pathogen. Although an effective HIV vacc…

HIV is a formidable pathogen. Although an effective HIV vaccine still remains elusive, drug therapy regimens that use a combination of drugs have proven successful for treating HIV-positive individuals. (a) Why is HIV such a difficult pathogen to treat? (b) Why is a combination of drugs needed to successfully treat HIV? (c) Why does the drug therapy need to be continued for life? Be specific!

Identify the unconditioned stimulus(UCS), Conditioned stimul…

Identify the unconditioned stimulus(UCS), Conditioned stimulus(CS), Unconditioned response(UCR) & Conditioned response(CR) in the following scenarios. John B. Watson conducted an experiment with a boy named Albert in which he paired a white rat with a loud,startling noise. Albert now becomes startled at the sight of the white rat.