The scientist who discovered the oxygen cycle in nature was:
A. All of the above contributed
B. Joseph Priestley
C. Antoine Lavoisier
D. Jan Ingenhousz
Answer: Option A
Solution (By JKSSB Mock Tests)
Joseph Priestley discovered oxygen, Lavoisier named it and explained combustion and respiration, Ingenhousz showed plants produce oxygen in light. Together, their work elucidated the oxygen cycle. So all contributed.
Explanation:
Selman Waksman coined the term 'antibiotic' in 1942 to describe chemical compounds produced by microorganisms that inhibit or kill other microbes. Fleming discovered penicillin, Ehrlich developed the concept of chemotherapy, Domagk discovered sulfa drugs.
Explanation:
Hemoglobin in red blood cells binds oxygen in the lungs and releases it in tissues. Each hemoglobin molecule can bind four O₂ molecules. It also carries some CO₂.
Explanation:
Alexander Fleming, a Scottish bacteriologist, discovered penicillin in 1928. He returned from a vacation to find that a Petri dish containing Staphylococcus bacteria had been accidentally contaminated by a mold. He noticed a clear zone around the mold where the bacteria had been killed. The mold was identified as Penicillium notatum, and the antibacterial substance was named penicillin.
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