Consider statements about microorganisms: 1. Penicillin is extracted from a fungus. 2. Streptomycin is extracted from a bacterium. 3. Viruses can be cultured in synthetic media. Which are correct? MCQ with Answer and Explanation

Explanation:
Rickets is characterized by weak, deformed bones due to impaired calcium deposition from lack of vitamin D. In adults, it's osteomalacia.

Explanation:
The root is divided into zones. The root hair zone contains epidermal extensions (root hairs) that vastly increase surface area, making it the primary region for water and mineral absorption. The zone of cell division (meristematic zone) is at the very tip, where active mitosis occurs; the zone of elongation is where cells expand in length, pushing the root tip forward. The root cap is a thimble-like structure protecting the delicate apical meristem as it pushes through soil. Thus, statements 1 and 3 are correct.

Explanation:
The tundra biome, found in Arctic and Antarctic regions, has permanently frozen subsoil (permafrost), extremely low temperatures, short growing seasons, and vegetation limited to mosses, lichens, grasses, and dwarf shrubs. Taiga is the boreal coniferous forest, savanna is tropical grassland, temperate deciduous forest has distinct seasons. Tundra is the coldest biome.