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Correct answer is (b) Thallus

(c) Mitochondria

Bacteria that live in harsh enviroment use chemicals (Ammonia, hydrogen sulphide) to produce their food instead of utilizing energy from the sun. This process is called chemosynthesis.

Disease causing organisms are called pathogens.

Example : The bacterium Mycobacterium tuberculosis causes tuberculosis in human beings.

Alexander Fleming discovered the antibiotic “Penicillin” in 1929.

The process of conversation of sugar into alcohol is known as fermentation. Louis Pasteur discovered fermentation in 1857.

Edward Jenner discovered the vaccine for smallpox in 1978.

Vaccination is the process of giving a vaccine orally or by injection which gives protection against a particular disease. Vaccination protect the children from number of diseases. Several diseases, including cholera, tuberculosis, smallpox and hepatitis can be prevented by vaccination.

Since the immune system of children is not strong and they are more likely to catch any disease very easily, so all the children should be vaccinated at the proper ages to provide them immunity from certain diseases.

B. Edward jenner 

Edward Jenner discovered the vaccine for smallpox in 1978.

The spreading of diseases by mosquitoes can be prevented by following ways: 

1. We should not let water collect anywhere in the neighborhood. 

2. We should keep our surrounding clean and dry. 

3. Mosquito repellant creams should be applied on the exposed parts of the body.

A vaccine is a special kind of preparation which provides immunity against a particular disease. Vaccine consists dead and weakened microbes which are harmless and do not cause any disease. 

Vaccine works as follows:

• When the vaccine containing dead or weakened microbes is introduced into the body of a healthy person, the body fights and kills the microbes by producing some substance called antibodies. 

• Some of the antibodies remain in the body for a long time and protect it from any future attack of disease germs. Thus, a vaccine develops the immunity from a disease.

There are various ways of preventing the occurrence and spreading of communicable diseases. 

These are as follows:

• Maintain personal hygiene and good sanitary habits. 

• Drink boiled drinking water. 

• Spray insecticides and control breeding of mosquitoes by not allowing water to collect in the surroundings. 

• Keep the infected person separated from others & advice him/ her to keep a handkerchief on the nose and mouth while sneezing. 

• Timely vaccination against diseases should also be taken. 

• Food must be kept covered.

It respires anarobically and has an enzyme called zymase to bring about fermentation .

Chlorophylls, fucoxanthin (brown), xanthophylls (yellow), phycoerythrin (red) phycocyanin (blue).

i. d 

ii. a 

iii. b 

iv. c

Correct answer is (b) virus.

(d) Both Assertion and Reason are false

(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion

Bacteria are described according to the shape of their cells. 

They are:

1. Bacilli – Rod shaped bacteria. 

2. Spirilla – Spiral shaped bacteria. 

3. Cocci – Spherical or ball shaped bacteria. 

4. Vibrio – Comma shaped bacteria.

Correct answer is (d) Tadpole

(a) peritrichous

Correct answer is (c) Trichoderma

1. False - Trichoderma is a biocontrol agents.

2. True.

3. False - Phycoerythin is a red pigment.

4. True 

5. True.

Correct answer is (b) Nostoc