Question

Discuss three ways in which bacteria are useful to us and three ways in which they are harmul.

Answer 1

Importance of bacteria:
- Normal flora: useful bacteria in the body limit the localisation of harmful bacteria by competition thus protecting against diseases.
- Bacteria are useful in the making of biofuels as they act as the digesters.
-Bacteria are natural decomposers in the enviroment and thus ensure recycling of energy and cleaning of the environment.
-Bacteria like rhizobium are useful to plants and animals as they convert atmospheric nitrogen to nitrates which then becomes the means by which proteins are gained by plants and ultimately by animals.

Harmful effect of bacteria:

-Bacteria causes diseases such as brucelloisis.
-Bacteria cause rotting of food.
-Bacteria such as plant bacteria can destroy food crops leading to loses and hunger.

Answer 2

  Bacteria uses:
1. In making of curd ( by Lacto bacillus bacteria)
2. Making of bread and alcohol in large production ( yeast is used)
3. Used in medicinal field as antibiotic example Pencillin
4. Fixation of nitrogen and decomposition of organic waste. .
Bacteria are harmful in the following ways:
1. Diseases like Cholera and typhoid are caused.
2. Streptococci cause a lot of sore throats .
3. Spoiling of food.