Consider all the different types of cells mentioned in this activity that participate in the immune response. which cells are responsible for the response to the second pathogen exposure illustrated in model 4? justify your reasoning.

lymphocytes

Explanation:

In immune system, there are three main group of cells that is the response of our defenses.

Neutrophils are one group responsible to be the first response, they travel all around our body trough the stream blood and can detect the first signals of infection.

Monocytes and macrophages, are another group of cells that can "eat" the bacteria or viruses and destroy them when they are inside our body.

The third group, the lymphocytes, are conformed by three group of cells, T - cells (that help to destroy infected or cancerous cells), B- cells (responsible to produce antibodies, so they are the ones that conformed our second barrier of defense) and the NK cells ( natural killers, the ones to control several types of cancer and microbial infections).

Hope this info is useful.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

b. heterotroph

explanation: