20 Φεβ 2013 (πριν από 4 χρόνια και 5 μήνες)

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Goal 7 EOG

The learner will conduct investigations,
use models, simulations, and appropriate
technologies and information systems to
build an understanding of

Comparing Microbes

Viruses: a particle that consists of nucleic acid
enclosed within a protein shell that requires a
living cell in order to reproduce. Viruses lack
nearly every characteristic of life (except they can
reproduce). Viruses either have DNA or RNA for
their genetic information. Viruses have a protein
shell called a capsid. Some viruses have an
envelope that aids in attaching to the cell that the
virus is going to attack.


Prokaryotes: unicellular organisms that do
not have a true nucleus and do not have
true membrane
bound organelles. Ex.

Eukaryotes: do have a true nucleus and
membranes around organelles. Ex.

Most microbes are prokaryotes


Bacteria are named by their shapes:

Coccus (looks like a coconut): means round

Bacillius: looks like a chain

Spirillum: looks like spaghetti noodles

Bacterial cells are enclosed by a cell wall: a rigid
structure that supports and protects the cell.
Bacterial cells do not have a nucleus.

Two kindgoms of bacteria: Archaebacteria and

Protists and Fungi

Protists are Eukaryotes: organisms that do have a
true nucleus and membrane
bound organelles.

Have both multicellular and unicellular organisms

Fungal cells have a cell wall

Fungal cells feed acting as decomposers, they
digest matter in the environment and then take
the matter they use as food into their cells.

Some fungi are parasites feeding on body fluids
and tissues of other organisms.

Microbe and Disease

Disease: any change that disrupts the normal
function of one or more body systems.

Noninfectious diseases: diseases that are
inherited and are not spread from one organism to

Pathogen: any microbe that causes disease

Infectious disease: disease that caused by a
pathogen and can be spread from one organism
to another. These diseases are called

Diseases caused by Viruses

Examples of diseases caused by viruses:

Influenza (flu)



Yellow fever


Severe Acute Respiratory Syndrome (SARS)


Cancer, like HPV or Human Papilloma Virus


Viruses cause disease by either damaging
or killing cells. It will attach itself to the cell
and inject it’s DNA or RNA into the cell.
The cell will then make copies of the viral
DNA/RNA everytime it goes through
mitosis. Eventually, the cell will burst and
the new viruses will be released into the
body of the organism being infected.

Diseases caused by bacteria




Food poisoning



Lyme disease

Stomach ulcers




Typhoid fever

Diseases caused by Protists





The protists that cause each of these diseases
are examples of parasites. Parasites: an
organism that derives nourishment or habitat from
the tissues or fluids of another organism.

How infectious Disease Spreads

Under ideal conditions, a bacterial cell can divide
as often as every 30 minutes.

A vector is an organism that helps spread
disease. Ex. Mosiquitos spread malara.

Epidemic: major outbreak of disease

Carrier: an organism that is infected with and can
transmit a disease
causing microbe to another
living organism, even though the carrier may not
show any symptom of the illness. Ex HIV is
spread by a carrier, who does not “look” sick.


Many contagious diseases such as the
common cold and the flu can be
transmitted directly from one perso to
another without a carrier.

Contagious disease: a disease that can be
spread from one person to another.

These can be transmitted through the air when a
person sneezes or coughs.

Sexually Transmitted Diseases

transmitted diseases: diseases
that are spread by sexual contact with an
infected person.

Examples: syphilis, gonorrhea, chlamdydia,
hepatitis, genital herpes, AIDS.

One of the most dangerous things about STDS is
that people can carry and spread most STDS
without even knowing that they are infected with
the disease.

Preventing and Treating Diseases

Helpful behaviors to prevent disease:

Avoid contact with a person who is ill

Washing your hands frequently

Eating nutritious foods

Maintaining a healthy body weight

Getting enough rest


There are two ways to get immunity to a disease:



Active immunity: obtained by exposure to the pathogen.
Your body becomes exposed and makes antibodies to help
destroy the pathogen. One way to get active immunity is by
getting a vaccine.

Passive immunity: involves transferring antibodies made in
one organism to another organism. Ex. A person who has
been vaccinated against rabies can give their rabies
antibodies to someone else who has been bitten by a dog
who has rabies.

Antimicrobial Products and

Antimicrobial products: a substance that is
designed to kill microbes before they can enter
your body. Ex. Many handsoaps and hand

Antibiotics: drugs that kill bacteria or prevent

Both antimicrobial products and antibiotics are
used to help prevent the spread of diseases.

Antibiotic Resistance

The decrease in the effectiveness of
penicillin is the result of a problem called
antibiotic resistance.

Antibiotic resistance: when bacteria
develops a tolerance to and survive
treatment with drugs that once killed them.
This happens from overuse of antibiotics
and because we do not always take all of
the medicine the doctor prescribes to us.

Biotechnology and Daily Life

Biotechnology: the use of living organisms, or parts of
organisms to produce products used by people. Some
products resulting from biotechnology include medications
and foods.

Biotechnology is used to produce vaccines. It is also used to
alter crops in agriculture to make them resistant to disease,
herbicides and frost.

Biotechnology provides jobs for the community.

The use of biotechnology presents ethical issues that the
scientific community must face. Concerns have been
expressed about the safety of genetically manipulated food