Question

Maximum time- 30 minutes
Maximum marks- 35
1. What are food preservatives? Name some
common food preservatives.
2 marks
2. Draw a systematic diagram of nitrogen cycle and
explain it.
4 marks
3. Explain the process of Pasteurization in brief.
3 marks
4. Explain in detail how vaccination works?
5. what are good microorganisms?explain some of the uses of good microorganisms. 2 marks​

Answer 1

Answer:

1. Salts and edible oils are the common chemicals generally used to check the growth of microorganisms. Therefore they are called preservatives. We add salt or acid preservatives to pickles to prevent the attack of microbes. Sodium benzoate and sodium metabisulphite are common preservatives.

2.The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems. ... Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification.

3.Pasteurization or pasteurisation is a process in which packaged and non-packaged foods (such as milk and fruit juice) are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life. ... Spoilage enzymes are also inactivated during pasteurization.

4.When you get a vaccine, your immune system responds to the vaccine the same way it would to the real germ. It: Recognizes the germ in the vaccine as being foreign. Responds by making antibodies to the germ in the vaccine, just as it would for the real germ.

5.Microorganisms are responsible for the following: Facilitating digestion of food we eat, and food that nourishes all animal and plant life. Keeping us healthy: Good microbes protect us from pathogens by colonising our bodies - so that there is less room for bad microbes to invade our bodies.