Pteridophytes are also known as: MCQ with Answer and Explanation

Explanation:
Sericulture is the process of rearing silkworms (primarily Bombyx mori) for the production of silk. The silkworm feeds on mulberry leaves (Morus alba) and spins a continuous filament of silk protein (fibroin) to form a cocoon around itself during its pupal stage. The cocoons are then boiled to kill the pupa and unwind the silk filament for textile production.

Explanation:
Typhoid fever is caused by Salmonella typhi, transmitted via contaminated food/water, causing high fever, abdominal pain, and rose spots. Widal test is used for diagnosis. Cholera is Vibrio cholerae, TB Mycobacterium, dysentery Shigella or Entamoeba.

Explanation:
Vitamin B₁₂ (cobalamin) contains a cobalt ion at the center of its corrin ring. It is the only vitamin that contains a metal. Iron is in heme, zinc in enzymes, magnesium in chlorophyll.