DNA contains the pentose sugar 2'-deoxyribose, which lacks an oxygen atom on the 2' carbon compared to ribose in RNA. This structural difference makes DNA more chemically stable and suitable for long-term genetic storage. Nucleotides consist of a nitrogenous base, a pentose sugar, and a phosphate group. Ribose is present in RNA.
Explanation:
Beta-carotene is a precursor of vitamin A (provitamin A) and imparts an orange color to carrots, pumpkins, and sweet potatoes. Lycopene gives red color to tomatoes, chlorophyll is green, xanthophyll is yellow. Beta-carotene is an antioxidant and is important for vision and immune function.
Explanation:
Mitochondria and chloroplasts contain their own DNA and ribosomes (70S) and can replicate by binary fission, a feature supporting their endosymbiotic origin. Golgi apparatus, lysosomes, and rough ER cannot self-replicate; they are part of the endomembrane system and arise from pre-existing membranes. Mitochondria are thus semi-autonomous organelles.
Consider statements about animal husbandry: 1. Dairy farming focuses on milk production. 2. Poultry farming focuses on meat and egg production. 3. Fisheries focus on silk production. Which are correct?
Explanation:
Dairy farming is the agricultural practice of breeding and raising livestock (like cows and buffaloes) specifically for the long-term production of milk. Poultry farming involves the rearing of domesticated birds (like chickens, ducks, and turkeys) for the production of meat (broilers) and eggs (layers). Fisheries (pisciculture) involves the breeding and rearing of fish and other aquatic organisms for food; silk production is the domain of sericulture (rearing silkworms). Thus, statements 1 and 2 are correct.
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