Microorganisms 3 Bacteria

Question 1

What do people add to warm milk to make yoghurt?

Answer 1

A spoonful of yoghurt

The spoonful of yoghurt contains millions of bacteria.

Question 2

What happens to the bacteria in the yoghurt when added to warm milk?

Answer 2

They grow and multiply in the milk.

Question 3

What do the bacteria produce in the milk?

Answer 3

An enzyme that turns the milk thick and a little sour.

Question 4

What are bacteria?

Answer 4

Bacteria are the simplest of organisms and are believed to be the first living beings to have appeared on earth.

Question 5

What is the cellular structure of bacteria?

Answer 5

Bacteria are unicellular, but they sometimes cling together to form colonies.

Question 6

How many different shapes can bacteria have?

Answer 6

Bacteria can have four different shapes and are named according to their shape.

Question 7

What are rod-shaped bacteria called?

Answer 7

Rod-shaped bacteria are called bacilli (singular: bacillus).

Question 8

What disease does Bacillus anthracis cause?

Answer 8

Bacillus anthracis causes the disease anthrax.

Question 9

What are spherical bacteria called?

Answer 9

Spherical bacteria are called cocci (singular: coccus).

Question 10

Which bacteria cause pneumonia?

Answer 10

Pneumonia is caused by Streptococcus pneumoniae.

Question 11

What are spiral bacteria called?

Answer 11

Spiral bacteria are called spirilla (singular: spirillum).

Question 12

What are comma-shaped bacteria called?

Answer 12

Comma-shaped bacteria are called vibrios (singular: vibrio).

Question 13

What do most bacteria have in common regarding their cell structure?

Answer 13

Most bacteria have a rigid cell wall and do not have a nucleus.

Question 14

Where is the nuclear material located in bacteria?

Answer 14

The nuclear material lies naked in the cytoplasm of bacteria.

Question 15

What structures do many bacteria have for movement?

Answer 15

Many bacteria have flagella or cilia to help them move.

Question 16

What are fimbriae?

Answer 16

Fimbriae (singular: fimbria) are thin outgrowths found in some bacteria.

Question 17

Can some bacteria make their own food?

Answer 17

Yes, a few bacteria can make their own food by a process similar to photosynthesis.

Question 18

What are the two main types of bacteria based on their nutritional habits?

Answer 18

Most bacteria are saprophytic or parasitic.

Question 19

Do all parasitic bacteria cause diseases?

Answer 19

No, not all parasitic bacteria cause diseases; some live harmlessly in our intestines.

Question 20

What are aerobic bacteria?

Answer 20

Aerobic bacteria need oxygen to break down food and release energy.

Question 21

What are anaerobic bacteria?

Answer 21

Anaerobic bacteria can live without oxygen.

Question 22

How fast can bacteria grow and multiply under favorable conditions?

Answer 22

Bacteria can grow and multiply very fast; for example, Escherichia coli takes about 20 minutes to reproduce.

Question 23

What are favorable conditions for bacterial growth?

Answer 23

Favorable conditions mean plenty of food, a temperature range of 30-37°C, and a moist environment.

Question 24

How do bacteria reproduce?

Answer 24

Bacteria reproduce by binary fission, a mode of asexual reproduction.

Question 25

What are some products made using bacteria?

Answer 25

Some bacteria are used to make alcohol, vinegar, yoghurt, and cheese from milk.

Question 26

What is fermentation?

Answer 26

Fermentation is the action of bacteria (and yeast) on carbohydrates used in various processes.

Question 27

What are some other products that involve bacteria?

Answer 27

Some bacteria are used in the production of tea, coffee, and tobacco.

Question 28

What are antibiotics?

Answer 28

Antibiotics are medicines used in the treatment of infectious diseases.

Question 29

How are some antibiotics produced?

Answer 29

Some antibiotics are produced with the help of bacteria.

Question 30

In which industries are bacteria used?

Answer 30

Bacteria are used in the tanning of leather and in the jute industry.

Question 31

How do bacteria help in the jute industry?

Answer 31

Bacteria act on the raw jute plant, which is immersed in water, to help in making fiber from the plant.

Question 32

What role do bacteria play in our intestines?

Answer 32

Bacteria living in our intestines help in the absorption of food and protect us from some diseases.

Question 33

How do herbivorous animals utilize bacteria?

Answer 33

Herbivorous animals depend on the bacteria living in their stomachs to break down the cellulose in the food they eat.

Question 34

What is the role of bacteria as decomposers?

Answer 34

Bacteria are among nature's decomposers, helping to keep the environment clean by breaking down animal excreta and the remains of plants and animals.

Question 35

How do bacteria contribute to nutrient recycling?

Answer 35

They help to recycle nutrients back into the soil.

Question 36

What products can be made using bacteria?

Answer 36

We use bacteria to make biogas and compost from waste.

Question 37

What is the role of bacteria in nitrogen conversion?

Answer 37

Bacteria convert atmospheric nitrogen into nitrates, which are needed by plants.

Question 38

What diseases can bacteria cause in humans?

Answer 38

Many plant and animal diseases are caused by bacteria, including typhoid, cholera, pneumonia, tetanus, tuberculosis, leprosy, and whooping cough.

Question 39

What are some bacterial diseases in plants?

Answer 39

Wilt and citrus canker are bacterial diseases in plants.

Question 40

How can bacteria spoil food?

Answer 40

If bacteria are used to process food, they are also responsible for spoiling food, causing milk to turn sour and butter to turn rancid.

Question 41

What dangerous food poisoning can bacteria cause?

Answer 41

Clostridium botulinum, which grows in badly preserved canned food, can cause a very dangerous kind of food poisoning called botulism.