Download Unit Question: What is life and how does it maintain balance? Notes

Unit Question: What is life and
how does it maintain balance?
Notes #8: The Immune System and
Homeostasis
Aim: What does your immune
system do?
Name:________________
Pathogens
• When an organism is unable to maintain
homeostasis, the organism has a disease
• Pathogens are viruses and bacteria that
cause disease
• The body’s immune system repels
pathogens and reestablishes
homeostasis
An Immune Attack
What the immune system does when a pathogen
enters the body:
1. Pathogens release antigens (foreign substances)
2. Antibodies are released by the immune system
to fight the pathogen.
3. Antibodies have receptors on their cell
membranes that recognize and bind to the
antigens.
Vaccines
• Weakened pathogens that are injected
into the body
• The body produces antibodies which
remain in the system in case of another
infection by the same pathogen
Salmonella bacteria can cause humans to have
stomach cramps, vomiting, diarrhea, and fever. The
effect these bacteria have on humans indicates
that Salmonella bacteria are
(1) Predators
(2) pathogenic organisms
(3) parasitic fungi
(4) decomposers
The virus that causes AIDS is damaging to the body because it
(1) targets cells that fight invading microbes
(2) attacks specific red blood cells
(3) causes an abnormally high insulin level
(4) prevents the normal transmission of nerve impulses
Many viruses infect only a certain type of cell
because they bind to certain
(1) other viruses on the surface of the cell
(2) mitochondria in the cell
(3) hormones in the cell
(4) receptor sites on the surface of the cell
Vaccinations help prepare the body to fight invasions of a
specific pathogen by
(1) inhibiting antigen production
(2) stimulating antibody production
(3) inhibiting white blood cell production
(4) stimulating red blood cell production
A vaccine used against an infectious disease may contain
(1) specialized blood cells
(2) toxic enzymes
(3) a variety of antibiotics
(4) weakened pathogens
The use of a vaccine to stimulate the immune
system to act against a specific pathogen
is valuable in maintaining homeostasis
because
(1) once the body produces chemicals to
combat one type of virus, it can more easily
make antibiotics
(2) the body can digest the weakened
microbes and use them as food
(3) the body will be able to fight invasions by
the same type of microbe in the future
(4) the more the immune system is
challenged, the better it performs
The virus that causes AIDS is damaging to the body because it
(1) targets cells that fight invading microbes
(2) attacks specific red blood cells
(3) causes an abnormally high insulin level
(4) prevents the normal transmission of nerve impulses
State one specific way white blood cells help to
protect the human body from
pathogens.
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