Consider statements about genetics: 1. Genes are made of DNA. 2. Chromosomes are located in the nucleus. 3. RNA is the genetic material in all cells. Which are correct? MCQ with Answer and Explanation

Explanation:
Biochemical Oxygen Demand (BOD) measures the amount of dissolved oxygen required by aerobic bacteria to decompose organic matter in water; high BOD indicates severe organic pollution. Eutrophication is the excessive enrichment of water bodies with nutrients (like nitrates and phosphates), leading to algal blooms and oxygen depletion. Biological magnification is the progressive increase in the concentration of non-biodegradable toxins (like DDT) at each successive trophic level, not a decrease. Thus, statements 1 and 2 are correct.

Explanation:
The pancreas is a mixed gland: exocrine acini secrete digestive enzymes (trypsin, lipase, amylase) into the duodenum, while endocrine islets secrete insulin and glucagon into the blood. The liver produces bile, not digestive enzymes. Spleen filters blood, gall bladder stores bile.

Explanation:
Chlorella and Spirulina (a cyanobacterium) are used as single-cell proteins and health supplements due to their high protein content (up to 60%) and essential nutrients. Gelidium is used for agar, Sargassum is a brown alga, Polysiphonia a red alga. Chlorella is a unicellular green alga.