Consider the following statements about carbohydrates: 1. Glucose is a monosaccharide. 2. Sucrose is a disaccharide. 3. Cellulose is a storage polysaccharide in plants. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
Blood clotting (coagulation) is a cascade of enzymatic reactions. When tissue is damaged, it releases thromboplastin (tissue factor). In the presence of calcium ions (Ca2+), thromboplastin activates the conversion of the inactive plasma protein prothrombin (synthesized in the liver with the help of Vitamin K) into the active enzyme thrombin. Thrombin then catalyzes the conversion of soluble fibrinogen into insoluble fibrin threads, forming the clot mesh.

Explanation:
Iodine is essential for the synthesis of thyroid hormones T₃ and T₄. Deficiency causes hypothyroidism and goiter (enlarged thyroid gland). Iodized salt is a preventive measure.

Explanation:
Chlorophyll a is the primary photosynthetic pigment that acts as the reaction center in photosystem I (P700) and II (P680), converting light energy to chemical energy. Accessory pigments like chlorophyll b, carotenes, and xanthophylls absorb light and transfer energy to chlorophyll a. Phytochrome is involved in photoperiodism. Without chlorophyll a, photosynthesis cannot occur.