The major greenhouse gas emitted from agricultural rice paddies is: MCQ with Answer and Explanation

Explanation:
Iodine is essential for synthesis of thyroxine (T₄) and triiodothyronine (T₃). Deficiency leads to enlargement of the thyroid gland, known as goiter, as the gland tries to compensate. Anemia is due to iron deficiency, rickets to vitamin D deficiency, scurvy to vitamin C deficiency. Iodized salt is a public health measure to prevent goiter.

Explanation:
Myoglobin is a red protein in muscle cells that stores oxygen and facilitates its diffusion during muscle contraction. It has a higher affinity for O₂ than hemoglobin, allowing oxygen transfer from blood to muscle. Hemoglobin is in RBCs, hemocyanin is in some invertebrates, cytochromes are electron carriers.

Explanation:
Glucagon, from the pancreatic alpha cells, raises blood glucose by stimulating glycogenolysis and gluconeogenesis in the liver. Cortisol and growth hormone also raise blood glucose but glucagon is the primary direct antagonist of insulin. Thyroxine increases metabolic rate. The balance between insulin (hypoglycemic) and glucagon (hyperglycemic) maintains glucose homeostasis.