Unit C:

DISEASE DEFENSE &

HUMAN HEALTH

~ SCIENCE 24 ~

Topics We’ll Cover

○ What is disease? What kinds are there?

○ How does our body protect us from disease?

○ Who is most at-risk for disease?

○ Should forced vaccinations be a thing?

○ What happens when antibiotics are abused/used improperly?

○ How are genetic diseases passed from parent to child?

Topic 1:

Disease

“I’m sick” could mean…

Disease

A disease is any condition that causes a disruption

in normal body functioning.

Diseases are caused by a variety of different

factors, including viruses, bacteria, fungi, the

environment, and genetics.

There are

countless

diseases… by

why can you

“catch” some

and not

others???

Types of DiseaseThere are two general types of diseases:

1) COMMUNICABLE

○ Diseases that are spread from

organism to organism (either by

direct or indirect contact)

○ Examples: malaria, measles, the

flu

2) NON-COMMUNICABLE

○ Medical conditions that are not

infectious (cannot be passed

from one organism to another)

○ Examples: heart disease,

cancer, asthma

Can you think of other examples?

Communicable

1. ____________________

2. ____________________

3. ____________________

Non-Communicable

1. ____________________

2. ____________________

3. ____________________

Note: communicable diseases are also called

________________________ diseases

Pathogens

○ Disease-causing agents

○ 3 types: Fungi, Viruses, Bacteria

1. Fungio Includes molds, yeasts, and mushrooms. o Some are parasites, and can live only on their “host”

organismso Examples: athlete’s foot, ringworm

2. Viruses

Viruseso Did you know that viruses are not really living

things??? o Viruses enter body cells, hijack their organelles, and turn

the cell into a virus making-factory. The cell will eventually burst, releasing thousands of viruses to infect new cells.

o The virus on its own, however, can’t do anything without a host.

Cell before infection… …and after.

3. Bacteria

Bacteria are EVERYWHERE…

Not all bacteria are bad. Some are actually

required for healthy functioning

Escherichia coli bacteria

in our digestive tract

help aid in digestion.

But E. coli bacteria are

also responsible for food

poisoning… so why are

we all not sick?

Only if E. coli are introduced in an unnatural manner can they become harmful

Good Bacteria?

Bad Bacteria

(click to play)

http://www.phac-aspc.gc.ca/phn-

asp/2017/outbreak-ecoli-eng.php

Current Food Recalls in

Canada http://www.inspection.gc.ca/about-the-

cfia/newsroom/food-recall-

warnings/eng/1299076382077/129907649384

6

Flour Recall: April 2017

● All Robin Hood flour

products recalled due to

E.coli contamination

● One individual seriously ill

with E.coli poisoning after

consuming the flour

● Dozens of other cases being

investigated

Bad Bacteria

3 Shapes of Bacterial Cells

Meet the Plaque Coating Your Teeth!

(click to play)

Conditions for Bacterial Growth

○ Bacteria need 5 things in order to reproduce & grow

Can We See Bacteria in Yogurt?

○ Some types of bacteria can ferment

milk, producing lactic acid in the

process. Yogurt is a product of

fermentation. It is acidic and stays fresh

longer than milk, and is also digested

more easily.

○ In this exercise you will prepare a

microscope slide of yogurt and

determine what shape of bacteria

yogurt contains