Download Brain Stretch 5

Brain Stretch 5
Crazy Scientist’s Experiment
In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in
culture dishes. He noticed that a mold called Penicillium was also growing in some
of the dishes. A clear area existed around the mold because all the bacteria that had
grown in this area had died. In the culture dishes without mold, no clear areas were
present.
Fleming hypothesized that the mold must be producing a chemical that killed the
bacteria. He decided to isolate this substance and test it to see if it would kill
bacteria. Fleming transferred the mold to a nutrient broth solution. This solution
contained all the materials the mold needed to grow. After the mold grew, he
removed it from the nutrient broth. Fleming then added the nutrient broth in which
the mold had grow to a culture of bacteria. He observed that the bacteria died.
1. Identify the problem.
2. What was Fleming’s hypothesis?
3. How was the hypothesis tested?
4. Should the hypothesis be supported or rejected based on the experiment?
5. This experiment lead to the development of what major medical advancement?
Infectious and Noninfectious Diseases
An infectious disease is an illness that is caused by pathogens that enter the body
through direct contact. Pathogens are disease-causing organisms. Infectious diseases
can spread by direct physical contact or through indirect contact.
Noninfectious diseases are illnesses that are not caused by pathogens. For example,
heart disease is not caused by coming into contact with a person who has heart
disease. Instead, heart disease can result from hereditary factors, improper diet,
smoking, and other risk factors.
Indicate in the second column of the table if the disease is an infectious disease.
Disease
Infectious (yes or no)
Allergy
Cystic Fibrosis
Strep Throat
Cancer
Common Cold
Diabetes
STDs
Pneumonia
http://www.dnatube.com/video/4330/White-Blood-Cell-Chases-Bacteria
Math Connection
Bacteria live in groups called colonies. Colonies are
usually circular. The diameter (distance across) of a
particular bacterial colony is 8 mm. The
circumference of a circle is equal to  (3.14) times
the diameter (C= d). What is the circumference of
the colony?
Science Scramble
Finish the sentence by unscrambling the italicized word.
1. Harmful bacteria in food can be killed with heat
during a process called nizutaspitorea.
2. eicVancns can prevent some bacterial infections.
3. Whiplike tails call elalgalf help bacteria move.
4. Rod-shaped bacteria are called cabllii.
5. Sphere-shaped bacteria are called ioccc.
6. siFnios is the simplest form of asexual
reproduction.
7. nPclnielil is a well-known antibiotic that works
by preventing bacteria from making cell walls.
8. An organism that uses oxygen for respiration is
an aeeobr.
What have you learned so far from
your classmates’ presentations?
Write a paragraph summarizing your
new-found knowledge about
bacteria.