1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
True [87]
3 years ago
6

In the early twentieth century, what was Alexander Fleming’s hypothesis concerning the relationship between a yellow-green mold

and certain strains of bacteria?
a. He thought the bacteria had released a chemical that caused the mold to grow. b.He thought the bacteria fed on the mold, causing it to shrink and disappear.
c. He thought the mold had released a chemical that prevented the bacteria’s growth.
Chemistry
1 answer:
SpyIntel [72]3 years ago
4 0

Answer:

The correct answer is the option c)He thought the mold had released a chemical that prevented the bacteria’s growth.

Explanation:

In the 1920s, Alexander Fleming was working in his laboratory at St. Mary's Hospital in London when, almost by accident, he discovered a naturally growing substance that could attack certain bacteria. In one of his experiments, Fleming observed that colonies of a bacterium had been depleted or removed by a mold that grew on the same Petri dish. He observed that the bacteria furthest from the fungus had grown to produce large-sized colonies, while the colonies closest to the fungus were tiny. He determined that mold made a substance that could dissolve bacteria. The fungus was penicilium chrysogenum and thus Fleming called this substance penicillin, by the name of the mold that produces it. Thus, after several years of experiments in 1930, Howard Florey and Ernest Chain developed at Oxford University the procedures to produce pure penicillin from the fungus that Fleming isolated. Thus penicillin could be concentrated by Florey and Chain, and in 1945 they shared with Fleming the Nobel Prize in Medicine.

Then, <u><em>the correct answer is the option c)He thought the mold had released a chemical that prevented the bacteria’s growth.</em></u>

You might be interested in
Which scientist is created with developing the first scientific atomic theory
Alona [7]
John Dalton was the first scientist
8 0
3 years ago
Find the volume of hydrogen gas formed when 1.5g of aluminum reacts with aq NaOH at 27 degrees Celcius.
Rudiy27

Answer:

how can I solve this ?4Al+3O2 produce 2Al2O3 find a) oxygen atoms needed to react with 5.4 g of aluminium b) grams of oxygen needed to react with 0.6 mol of aluminium?

(A) n=m/M,

n(Al)=5.4/27=0.2 moles

n(O2)=n(Al)*3/4=0.2*3/4=0.15 moles

Number of oxygen atoms= n(O2)*Avogadro's number

=0.15*6.02*10^23=9.03*10^22 oxgyen atoms

(B)

n=m/M

n(Al)=0.6/27=0.02222 moles

n(O2)=n(Al)*3/4=0.016666 moles

m=n*M

m(O2)=0.0166666*32=0.53333 grams

8 0
2 years ago
Which is NOT a phase of mitosis?
ss7ja [257]
Interphase is not a phase of mitosis.
3 0
3 years ago
Read 2 more answers
The main reason that cs2 has a higher boiling point than co2 is that cs2
OlgaM077 [116]

Explanation:

Inspite of having similar intermolecular forces, CS2 has a higher boiling point than CO2, since it has a greater molar mass. The potential energy of molecules reduces until a certain level as they get closer to each other. Although the polarity of both CO2 and CS2 are cancelled because of their linear structure.

4 0
3 years ago
What is the percent yield for a reaction if we predicted the formation
bogdanovich [222]

Answer:

18.1%

Explanation:

5 0
3 years ago
Other questions:
  • Protons are positively charged particles and neutrons have no charge. On the other hand, electrons are negatively charged specie
    11·1 answer
  • What is the most complex scientific formula?
    11·1 answer
  • 1. For dry air at 1.0000 atm pressure, the densities at –50°C, 0°C, and 69°C are 1.5826 g dm–3 , 1.2929 g dm–3, and 1.0322 g dm–
    10·1 answer
  • Please help thanks very much extra points given
    5·2 answers
  • Epsom salts is a hydrated ionic compound with the following formula: MgSO4⋅x H2O. A 4.93-g sample of Epsom salts is heated to dr
    8·1 answer
  • 32g of sulfur will react with48g of oxygen to produce 80g of sulfur trioxide. If 16g of sulfur and 100g of oxygen are placed int
    5·1 answer
  • 30 POINTS
    9·2 answers
  • What does the "R-" represent?
    9·2 answers
  • 1) What is the formula for calculating weight
    15·1 answer
  • Methane is the chief constituent of petroleum fuel <br> A:yes <br> B:no
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!