Consider statements about biotechnology: 1. Plasmids are used as vectors. 2. Restriction enzymes are found in viruses. 3. PCR requires DNA polymerase. Which are correct? MCQ with Answer and Explanation

Explanation:
Xylem is a complex permanent tissue composed of tracheids, vessels, xylem parenchyma, and xylem fibers. It conducts water and dissolved minerals from roots to aerial parts unidirectionally. Phloem transports organic nutrients bidirectionally. Cortex is ground tissue for storage, epidermis provides protection. Xylem vessels are dead at maturity, with lignified walls.

Explanation:
During intense exercise, when oxygen supply is insufficient, muscle cells switch to anaerobic glycolysis, producing ATP and lactic acid from glucose. Lactic acid accumulation lowers pH, causing muscle fatigue, soreness, and cramps. It is later converted back to glucose in the liver (Cori cycle). Ethanol is produced by yeast fermentation.

Explanation:
The IUCN Red List (Red Data Book) documents the conservation status of plants, animals, and fungi, categorizing species from Extinct to Least Concern. It highlights species at risk of global extinction. It is a critical tool for conservation policy and action. Endangered species like the Bengal tiger and snow leopard are listed. The Red Data Book was first published by IUCN in 1964.