Black gram
Explanation
Crops are classified based on their primary nutritional components and economic utility. While most crops contain a mix of nutrients, they are categorized by their dominant constituent: cereals for carbohydrates, pulses (legumes) for proteins, and oilseeds for fats and oils.
Option Analysis
- Wheat is incorrect: Wheat is a cereal crop. It is primarily cultivated as a source of carbohydrates (starch). Although it contains gluten (a protein), its primary nutritional contribution is energy through carbohydrates.
- Black gram is correct: Black gram (Vigna mungo), commonly known as Urad, is a pulse or legume. Pulses are cultivated specifically for their high protein content, making them the main source of protein in vegetarian diets.
- Linseed is incorrect: Linseed (Flax) is primarily an oilseed crop cultivated for extracting oil and fibers. Its major nutritional component is fat (oil).
- Sorghum is incorrect: Sorghum (Jowar) is a millet or coarse cereal. Like wheat, it is primarily a source of carbohydrates and dietary fiber.
Key Takeaway: Leguminous crops (pulses) such as black gram are the primary sources of plant-based protein, whereas cereals (wheat, sorghum) provide carbohydrates, and oilseeds (linseed) provide fats.