The deficiency of vitamin A causes: MCQ with Answer and Explanation

Explanation:
Bacteria are unicellular prokaryotic organisms, characterized by the absence of a true, membrane-bound nucleus and other membrane-bound organelles. Fungi are eukaryotic organisms, possessing a true nucleus and membrane-bound organelles, and can be unicellular (yeasts) or multicellular (molds, mushrooms). Viruses are acellular, non-cellular entities; they consist of genetic material (DNA or RNA) enclosed in a protein coat (capsid) and lack any cellular structure or independent metabolic machinery. Thus, statements 1 and 2 are correct.

Explanation:
The Krebs cycle, also known as the citric acid cycle or TCA cycle, is the central metabolic pathway for the oxidation of acetyl-CoA to produce energy (ATP, NADH, FADH2). It was discovered by the British-German biochemist Sir Hans Adolf Krebs in 1937. He was awarded the Nobel Prize in Physiology or Medicine in 1953 for this discovery. Melvin Calvin elucidated the carbon pathway in photosynthesis.

Explanation:
Erythroblastosis fetalis (hemolytic disease of the newborn) is primarily caused by Rh incompatibility. It occurs when an Rh-negative mother carries an Rh-positive fetus. During the first pregnancy, fetal Rh+ red blood cells may enter the mother's circulation, prompting her to produce anti-Rh antibodies. In subsequent pregnancies with an Rh+ fetus, these antibodies cross the placenta and destroy the fetal red blood cells, causing severe anemia and jaundice.