v) A protozoan
vi) A virus
e) causing cholera
a) fixing nitrogen
b) setting of curd
c) baking of bread
d) causing malaria
f) causing aids
1. Cholera is a bacterial disease which is spread through contaminated food and water. Cholera causes severe diarrhea and dehydration.
2 . Rhizobium is a bacteria which is associated with the formation of root nodules in plants. These bacteria live in a symbiotic relationship with legumes. They obtain nitrogen from the atmosphere and pass it on to the plant, thus allowing it to grow with proper metabolism.
3 . Lactobacillus is a rod-shaped, gram-positive, non-spore forming bacteria which helps in setting curd. Lactobacilli are very good for gut health. They produce lactic acid, which prevents many harmful bacteria from colonizing and infecting the intestines.
4 . Yeast is used for the leavening (rising the dough) of bread. Yeast uses glucose and oxygen in dough to produce more yeast cells and thus many yeast cells increases the production of carbon dioxide. Thus the carbon dioxide makes the dough rise which gives the bread a light and spongy texture.
5 . Malaria is caused by the protozoa Plasmodium which acts as a parasite. This protozoa is spread to the human through the bites of infected mosquitoes. Female anopheles mosquito carries the protozoa and while having its blood meals, it transfers this protozoa into human blood which lives inside human body as a parasite and later causes malaria.
6 . Acquired immunodeficiency syndrome (AIDS) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging the immune system, HIV interferes with the body's ability to fight infection and disease.