Which of the following is a communicable disease? MCQ with Answer and Explanation

Explanation:
Active transport requires energy (ATP) to move molecules against their concentration gradient. The Sodium-Potassium pump (Na+/K+ ATPase) is a classic example, moving 3 Na+ ions out of the cell and 2 K+ ions into the cell per ATP hydrolyzed. Osmosis, diffusion, and facilitated diffusion are passive processes.

Explanation:
Prokaryotes lack membrane-bound organelles like mitochondria, Golgi apparatus, and endoplasmic reticulum. They have 70S ribosomes, a single circular chromosome in a nucleoid, and typically a cell wall (except Mycoplasma). Eukaryotes possess membrane-bound organelles. This fundamental difference defines the two major cell types in the living world.

Explanation:
Late blight of potato is caused by the oomycete Phytophthora infestans (historically considered a fungus). It caused the Irish Potato Famine. Tobacco mosaic is viral, citrus canker is bacterial (Xanthomonas), crown gall is bacterial (Agrobacterium tumefaciens). Fungal plant diseases also include rust, smut, and powdery mildew. Oomycetes are now classified under Chromista but traditionally studied in mycology.