4. Answer the following questions in brief.
a) What are microorganisms?
b) What are the different ways in which communicable diseases spread?
c) How are viruses different from other microorganisms?
d) What is fermentation? Which microorganism has an active role in fermentation?
e) What is the utility of Lactobacillus bacteria?
f) What is the nitrogen cycle and why is it important?
g) What is pasteurization?
h) How does salt preserve food items?
i) What is anthrax?
1) Write the names of a few diseases caused by microorganisms in plants.
Answers
Answer:
a) microorganism, or microbe, is a microscopic organism, which may exist in its single-celled form or a colony of cells. The possible existence of unseen microbial life was suspected from ancient times, such as in Jain scriptures from 6th century BC India.
b) communicable disease is one that is spread from one person to another through a variety of ways that include: contact with blood and bodily fluids; breathing in an airborne virus; or by being bitten by an insect.
c)Unlike bacteria, viruses can't survive without a host. They can only reproduce by attaching themselves to cells. In most cases, they reprogram the cells to make new viruses until the cells burst and die.
d) Fermentation is the process by which glucose is converted into either alcohol or lactic acid in the absence of oxygen. It is also known as anaerobic respiration. Fermentation occurs in some bacteria, yeasts and in the muscles during heavy exercise. Yeast (fungi) converts sucrose into ethyl alcohol.