Biology Unit VI: Microorganisms and Diesease

Theroux

alternation of generations

a life cycle that has two phases, a haploid (N) phase and a diploid (2N) phase.

capsid

a protein coat surrounding a virus.

antibiotic

a drug used to block the growth and reproduction of bacterial pathogens.

mycelium

a densely branched network of the hyphae of a fungus.

saprophytic

a way of obtaining nutrients by absorbing dissolved organic matter from dead organisms, used by decomposers.

virus

a particle made of genetic information surrounded by a protein shell, and sometimes lipids, that can replicate only by infecting living cells.

lysogenic infection

a type of infection in which a virus embeds its DNA into the DNA of the host cell, and is replicated along with the host cell's DNA.

chitin

a complex carbohydrate that makes up the cell walls of fungi, and is also found in the external skeletons of arthropods.

prokaryote

a unicellular organism that lacks a nucleus.

pathogen

a microorganism or virus that causes an infectious disease.

mycorrhiza

a symbiotic association of plant roots and fungi.

binary fission

a type of reproduction in which a prokaryote divides in half, producing two identical cells.

endospore

a structure produced by prokaryotes in unfavorable conditions; a thick internal wall that encloses the DNA and a portion of the cytoplasm.

cilia

short hairlike projections from a cell that produce movement.

vaccine

a treatment used to produce immunity to an infectious disease.

hypha

a chain of cells forming long slender filaments that makes up the body of a fungus.

bacteriophage

a kind of virus that infects bacteria.

prophage

a piece of viral DNA that has been embedded in the DNA of a host cell.

lichen

a symbiotic relationship between a fungus and a photosynthetic algae or cyanobacteria.

flagellum

a long whiplike structure used by some cells for movement.

retrovirus

a virus that contains RNA as its genetic information rather than DNA.

interleukin

a type of signaling protein that allows immune cells to communicate.

macrophage

a large phagocyte that engulfs pathogens and helps activate the adaptive immune system by identifying antigens.

immunity

the ability of the body to resist disease.

thymus

an organ where T-cells mature.

lymph node

a structure that filters lymph, stores white blood cells, and traps pathogens.

helper t-cell

a cell that coordinates the immune response by amplifying and broadcasting messages to activate other immune cells.

bone marrow

soft tissue inside bones where blood cells, including immune cells, are produced.

adaptive immunity

a slower, specific immune response that targets particular pathogens and creates memory for future protection.

antibodies

proteins that bind to specific antigens to help neutralize or mark pathogens for destruction.

cytotoxic t-cell

a white blood cell that kills infected body cells.

antigen

a molecule on a pathogen that the immune system recognizes as foreign.

plasma cell

a B-cell that produces large amounts of antibodies.

skin

a physical barrier that prevents pathogens from entering the body.

autoimmune disease

a condition in which the immune system attacks the body's own cells.

memory cell

a long-lived cell that remembers a pathogen for faster response in the future.

leukocyte

a white blood cell that helps defend the body against infection.

inflammatory response

a reaction to injury or infection that causes redness, swelling, heat, and pain as the body works to fight pathogens.

histamine

a chemical released by infected or damaged cells that increases blood and lymph flow and causes inflammation.

allergy

an overreaction of the immune system to a harmless substance, like pollen or food.

lymph

a clear fluid that carries immune cells throughout the body.

innate immunity

the body's first line of defense; a fast, non-specific response that you are born with, including skin and inflammation.

mucus membranes

linings in areas like the nose, mouth, and lungs that trap pathogens in sticky mucus.

b-cells

white blood cells that can become plasma cells or memory cells in response to infection.

neutrophil

a fast-acting phagocyte that is one of the first cells to respond to infection.

phagocyte

a type of leukocyte that engulfs and digests pathogens.