Chapter 14 &15 Questions for Exam 3

Name the process used by microorganisms where they keep on changing their surface antigens to make antibodies ineffective?

Antigenic variation

Where are lysosomes found in the body?

In body secretions like tears, saliva, breastmilk, mucus

What is a disease vector?

Living organism that carries/transmits an infectious pathogen from one host to another (virus, parasite, bacterium)

Define biological transmission

Pathogen reproduces in the vector; transmitted via bites or feces (mosquitoes transmit malaria)

What is a superantigen?

Cause an intense immune response due to release of cytokines from host cells (T cells) (vomiting, shock, death)

How do we know which microbe is more dangerous?

The test measure the relative virulence/ potency under experienced conditions

Define LD50

Lethal dose for 50% of a sample population/measures potency of a toxin

Define ID50

Infectious dose for 50% of a sample population/measures virulence of a microbe

Define species resistance

Organism’s innate, natural ability to avoid or repel a pathogen or disease that commonly affects other species

A disease acquired by many people in given area in a short time (state/city)

Epidemic

A disease constantly present in a population (malaria in Africa)

Endemic

A disease that occurs only occasionally (ebola)

Sporadic

Disease worldwide epidemic (covid-19)

Pandemic

Define Endotoxin

Lipopolysaccharides (LPS) molecules located in the outer cell membrane of gram-negative bacteria like E. coli/ Pseudomonas

Define Human Microbiome

The microbial communities found on the human body (remain throughout life)

Define Normal Microbiota

Childhood exposure to microorganisms helps the immune system develop. They TRAIN the immune system.

The relationship between normal microbiota and host

Symbiosis

Define Commensalism

One organism benefits and the other is unaffected. (dead cells)

Define Mutalism

Both organisms benefit. (very bad)

Define Parasitism

One organism benefits at the exposure of the other. (bad)

In the Infectious Disease what are the signs?

Changes in a body that can be measured or observed as a result of disease. (fever/BP)

Number of new cases of disease that occur within a particular time period

Incidence

Define Herd Immunity

Immunity in most of a population

Transmission from mother to fetus or newborn at birth. EX “hepatitis, herpes, gonorrehea

Congenital Transmission