Selman Waksman, who discovered streptomycin, coined the term 'antibiotic' in 1942 to describe chemical substances produced by microorganisms that inhibit or kill other microorganisms. Fleming discovered penicillin but did not coin the term. Pasteur developed pasteurization and rabies vaccine, Ehrlich discovered salvarsan (magic bullet) for syphilis.
Consider the following statements about antibodies:
1. They are produced by T-lymphocytes.
2. They are also called immunoglobulins.
3. They specifically bind to antigens.
Which of the above is/are correct?
Explanation:
Antibodies are produced by B-lymphocytes (plasma cells), not T-cells. They are immunoglobulins that bind specific antigens. Thus, 2 and 3 are correct.
Explanation:
Fungi are heterotrophic organisms; they cannot perform photosynthesis because they lack chlorophyll and chloroplasts. They obtain nutrients through absorption after extracellular digestion (saprophytic or parasitic). The cell wall contains chitin, and most are multicellular with a filamentous body (mycelium), though yeasts are unicellular. Thus, autotrophy is not a fungal characteristic.
Explanation:
The Calvin cycle (C3 cycle) occurs in the stroma of chloroplasts, where COâ‚‚ is fixed into sugars using ATP and NADPH from light reactions. Thylakoid membrane is the site of light reactions.
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