Question

how penicillin was discovered
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 the 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 grown 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?

applying the scientific method
part a:
the statements provided outline how a problem was solved using the scientific method. however the statements are not in order.
put the statements in the correct order, by placing the correct number beside each statement.
i. which statement gives the problem/purpose?
ii. which statement gives the hypothesis?
iii. which statement gives the apparatus?
iv. which statement gives the procedure?
v. which statement gives the observation?
vi. which statement gives the conclusion?

a) i made soup and ate it slowly ___
b) i collected pot, spoon, water and soup mix ___
c) the stomach pains went away ___
d) i thought i might be hungry ___
e) one day at 11:30 am i had stomach pains ___
f) the stomach pains were caused by hunger ___

part b:
the statements below outline how a problem was solved using the scientific method. however the statements are not in order. identify the stages of the scientific method, then please put them in order.

a) the clock started when i plugged it back in _______________
b) i obtained a new plug and a screwdriver _______________
c) i noticed that the electric clock had stopped and that a radio plugged into the same outlet was working _______________
d) i guessed that the plug of the clock was damaged _______________
e) there must have been something wrong with the plug _______________
f) i took off the old plug and put in a new one _______________

Explanation:

Part A

i. Problem/Purpose

The problem/purpose is identifying the issue. Statement e ("One day at 11:30 AM I had stomach pains") presents the problem (stomach pains), so it's for problem/purpose.

ii. Hypothesis

A hypothesis is a guess. Statement d ("I thought I might be hungry") is a guess about the cause, so it's the hypothesis.

iii. Apparatus

Apparatus are the materials. Statement b ("I collected pot, spoon, water and soup mix") lists materials, so it's apparatus.

iv. Procedure

Procedure is the action taken. Statement a ("I made soup and ate it slowly") describes the action, so it's procedure.

v. Observation

Observation is what's seen. Statement c ("The stomach pains went away") is what was observed, so it's observation.

vi. Conclusion

Conclusion is the result. Statement f ("The stomach pains were caused by hunger") is the conclusion about the cause, so it's conclusion.

Ordering:

• i. e
• ii. d
• iii. b
• iv. a
• v. c
• vi. f

Part B

Step 1: Identify Stages and Order

1. Observation: Notice the problem. Statement c ("I noticed that the electric clock had stopped and that a radio plugged into the same outlet was working") is the observation.
2. Hypothesis: Guess the cause. Statement d ("I guessed that the plug of the clock was damaged") is the hypothesis.
3. Apparatus: Gather materials. Statement b ("I obtained a new plug and a screwdriver") is apparatus.
4. Procedure: Take action. Statement f ("I took off the old plug and put in a new one") is procedure.
5. Observation (Result): See the outcome. Statement a ("The clock started when I plugged it back in") is the result observation.
6. Conclusion: State the result. Statement e ("There must have been something wrong with the plug") is the conclusion.

Order: c (1), d (2), b (3), f (4), a (5), e (6)

How Penicillin Was Discovered

6. Identify the problem

The problem was that bacteria (Staphylococcus) were dying around the Penicillium mold in culture dishes, while they grew normally without the mold.

7. What was Fleming’s hypothesis?

Fleming hypothesized that the mold (Penicillium) must be producing a chemical that killed the bacteria.

8. How was the hypothesis tested?

He isolated the substance from the mold, transferred the mold to a nutrient broth solution, let the mold grow, removed it from the broth, and then added the nutrient broth (with the mold - produced substance) to a culture of bacteria to see if the bacteria died.

9. Should the hypothesis be supported or rejected based on the experiment?

Supported, because when he added the nutrient broth (with the mold - produced substance) to the bacteria culture, the bacteria died, matching the prediction of his hypothesis.

10. This experiment lead to the development of what major medical advancement?

This experiment led to the development of penicillin, the first antibiotic, which revolutionized the treatment of bacterial infections.

Answer:

Part A

i. Problem/Purpose

The problem/purpose is identifying the issue. Statement e ("One day at 11:30 AM I had stomach pains") presents the problem (stomach pains), so it's for problem/purpose.

ii. Hypothesis

A hypothesis is a guess. Statement d ("I thought I might be hungry") is a guess about the cause, so it's the hypothesis.

iii. Apparatus

Apparatus are the materials. Statement b ("I collected pot, spoon, water and soup mix") lists materials, so it's apparatus.

iv. Procedure

Procedure is the action taken. Statement a ("I made soup and ate it slowly") describes the action, so it's procedure.

v. Observation

Observation is what's seen. Statement c ("The stomach pains went away") is what was observed, so it's observation.

vi. Conclusion

Conclusion is the result. Statement f ("The stomach pains were caused by hunger") is the conclusion about the cause, so it's conclusion.

Ordering:

• i. e
• ii. d
• iii. b
• iv. a
• v. c
• vi. f

Part B

Step 1: Identify Stages and Order

1. Observation: Notice the problem. Statement c ("I noticed that the electric clock had stopped and that a radio plugged into the same outlet was working") is the observation.
2. Hypothesis: Guess the cause. Statement d ("I guessed that the plug of the clock was damaged") is the hypothesis.
3. Apparatus: Gather materials. Statement b ("I obtained a new plug and a screwdriver") is apparatus.
4. Procedure: Take action. Statement f ("I took off the old plug and put in a new one") is procedure.
5. Observation (Result): See the outcome. Statement a ("The clock started when I plugged it back in") is the result observation.
6. Conclusion: State the result. Statement e ("There must have been something wrong with the plug") is the conclusion.

Order: c (1), d (2), b (3), f (4), a (5), e (6)

How Penicillin Was Discovered

6. Identify the problem

The problem was that bacteria (Staphylococcus) were dying around the Penicillium mold in culture dishes, while they grew normally without the mold.

7. What was Fleming’s hypothesis?

Fleming hypothesized that the mold (Penicillium) must be producing a chemical that killed the bacteria.

8. How was the hypothesis tested?

He isolated the substance from the mold, transferred the mold to a nutrient broth solution, let the mold grow, removed it from the broth, and then added the nutrient broth (with the mold - produced substance) to a culture of bacteria to see if the bacteria died.

9. Should the hypothesis be supported or rejected based on the experiment?

Supported, because when he added the nutrient broth (with the mold - produced substance) to the bacteria culture, the bacteria died, matching the prediction of his hypothesis.

10. This experiment lead to the development of what major medical advancement?

This experiment led to the development of penicillin, the first antibiotic, which revolutionized the treatment of bacterial infections.