Consider the following statements about enzymes: 1. They are biological catalysts. 2. They are consumed in the reaction. 3. They lower the activation energy of reactions. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
Vitamin C is chemically L-ascorbic acid. It is water-soluble, an antioxidant, and required for collagen synthesis. Deficiency causes scurvy. It is found in citrus fruits, amla, and green vegetables.

Explanation:
Viruses are non-living outside a host; they cannot carry out metabolic processes or reproduce independently. They hijack the host cell's machinery to replicate. Thus, they are obligate intracellular parasites. The reason correctly explains the assertion.

Explanation:
The Casparian strip is a band of cell wall material that runs radially and transversely through the cell walls of the endodermal cells in plant roots, but is absent from the tangential walls. It is primarily composed of suberin (a waxy, waterproof substance) and lignin (a complex polymer). This strip acts as a physical and chemical barrier, blocking the passive, apoplastic flow of water and dissolved minerals between the cells. It forces these substances to cross the selectively permeable plasma membrane and enter the symplastic pathway, allowing the plant to control what enters the vascular cylinder.