Mid Term Exam #2 Study Guide Bio 11

Microorganisms

Widely distributed organisms in the environment that perform many beneficial functions; can also cause infectious diseases.

Pathogens

Microbes, such as bacteria and viruses, that cause diseases in humans.

Bacteria

Single-celled prokaryotic organisms with a unique cell wall structure, capable of reproducing by binary fission.

Viruses

Acellular obligate parasites that require a living host cell to replicate; consist of a capsid and nucleic acid core.

Prions

Infectious protein particles that cause degenerative diseases of the nervous system by misfolding normal proteins.

Lymphatic System

Network of vessels and organs responsible for absorbing excess tissue fluid, transporting fats, producing lymphocytes, and defending against pathogens.

Acquired Immunity

Immunity that develops after exposure to specific antigens, relying on the action of specific lymphocytes.

B Cells

Lymphocytes that produce antibodies and can develop into plasma cells and memory B cells.

Antibodies

Y-shaped molecules also known as immunoglobulins, responsible for recognizing and binding to antigens.

T Cells

Lymphocytes that directly attack infected or cancerous cells and assist both innate and acquired