Which of the following is true about blood group O?
A. Has both A and B antigens
B. Has no antibodies
C. Has only A antigens
D. Has anti-A and anti-B antibodies
Answer: Option D
Solution (By JKSSB Mock Tests)
Blood group O lacks A and B antigens on red cells but contains both anti-A and anti-B antibodies in plasma. This makes it the universal donor for packed red cells but dangerous plasma donor. Group AB has no antibodies. So, the presence of both antibodies is correct.
Explanation:
Electron microscopes use beams of electrons to achieve much higher resolution than light microscopes, enabling visualization of organelles and macromolecular complexes. Types include TEM (internal) and SEM (surface). Light microscopes use visible light, spectrophotometry measures absorbance, chromatography separates.
Explanation:
The Chipko movement, initiated in the 1970s in Uttarakhand (India), involved villagers (mainly women) hugging trees to prevent them from being cut down by contractors. It was a non-violent protest for forest conservation and sustainable use. Sunderlal Bahuguna was a prominent leader. It raised awareness about deforestation and environmental protection.
Explanation:
Xanthophylls, oxygenated carotenoids, are responsible for the yellow color of egg yolk, autumn leaves, and corn. Beta-carotene is orange, lycopene red.
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