In HIV-infected patients, there is a gradual loss of CD4+ T cells over time. These cells, also called T helper cells, organize the immune system's attack on disease-causing invaders, like Salmonella.
Answer:
A. What causes some people to be color-blind?
Explanation:
This is something that could be tested with different variables including DNA, or past family medical history.
I would say C! Most developing countries have high birth and death rates, while developed countries are more steady.
Answer:
c is just wrong because that is not how evolution works evolution is a small change in the DNA that takes a long time through many many generations not just as you or an organism get older and smarter you are not evolving
