<h3>Global travel and spread of certain species</h3>
Explanation:
Many pathogenic species of bacteria, virus, and other microbes are more prevalent in developing or tropical countries rather than in developed countries.
When an individual’s immune system is weak they become more susceptible to get infected and become carriers of that particular species.
The species grows, develops, and multiplies in the host’s body and when the traveler travels to his/her home country or any other place he/she can transmit the disease to others and again the species grows in numbers. Higher the rate of spread of infection higher is the increase in species.
I believe the answer is C
Solution:
The difference between them are:
The humoral system of immunity is also called the antibody-mediated system because of its use of specific immune-system structures called antibodies. The first stage in the humoral pathway of immunity is the ingestion (phagocytosis) of foreign matter by special blood cells called macrophages. The macrophages digest the infectious agent and then display some of its components on their surfaces. Cells called helper-T cells recognize this presentation, activate their immune response, and multiply rapidly. While,
The cell-mediated immune response involves cytotoxic T-cells, or killer-T cells. Body cells that have been infected by foreign matter often present components of that material on their surfaces. Killer-T cells recognize these displays and respond by ingesting or otherwise destroying the infected cell. Killer-T cells are also important in the body's defenses against parasites, fungi, protozoans, and other larger cells that might have found their way into the body. The killer-T cells recognize these large invaders by their foreign proteins and then destroy them.
This is the required answer.
