RRB NTPC Mains or Stage 2 Model Paper 7 with solutions

(a) Blue-green algae or Cyanobacteria are microscopic cells that grow naturally in Australian fresh and salt waters. They area type of bacteria, but in some ways act like plants by using sunlight to manufacture carbohydrates from carbon dioxide and water, a process known as photosynthesis. In doing so, they release oxygen. They grow in dams, rivers, creeks,reservoirs, lakes and even hot springs.