13: Microorganisms

Question 1

Microorganisms definition

Answer 1

Microorganisms are very tiny living things that usually can only be seen using a microscope

Question 2

What is a colony

Answer 2

A colony is many of the organisms together

Question 3

Microorganisms include what?

Answer 3

Viruses, bacteria, microscopic fungi

Question 4

What do some scientists classify as not organisms at all

Answer 4

Some scientists argue that viruses are non-livibg and therefore are not living organisms at all

Question 5

What are viruses totally dependant on? And what does this make him? What can they not do?

Answer 5

Viruses are totally dependent on a host cell (a cell they live in). They are parasites. They cannot grow or reproduce outside another cell.

Question 6

What human diseases are caused by viruses?

Answer 6

Colds, influenza, chicken pox, mumps, measles, german measles, hepatitis, AIDS, ebola

Question 7

What happens when the virus uses the cells DNA ?

Answer 7

Cells are damaged when the virus uses the cell’s DNA and other cell contents for its own purposes.

Question 8

What are viruses immune to?

Answer 8

Viruses are not affected by antibiotics

Question 9

Vaccination definition

Answer 9

Vaccination is when a harmless version of a disease is introduced into a person in order to stimulate the production of antibodies and white blood cells against the disease

Question 10

What happens when a vaccinated person comes in contact with the actual disease?

Answer 10

After a person is vaccinated, if they come I contact with the actual disease, their body will be able to fight it

Question 11

Name the uses of useful viruses

Answer 11

Some viruses kill bacteria that are harmful to humans.

Viruses are used in genetic engineering.

Question 12

Pathogens definition

Answer 12

Pathogens are microorganisms that cause disease

Question 13

Name some diseases caused by bacteria

Answer 13

Cholera, tetanus, tuberculosis, dental caries (tooth decay), strep throat, food poisoning

Question 14

Name some good bacteria and uses

Answer 14

Bacteria, known as decomposers, break down dead organic matter.
They help recycle carbon and nitrogen I the carbon cycle and the nitrogen cycle.
They are used in the making of some antibiotics.
They are used in the genetic engineering of some very useful products.
They plan a vital role in human health through their activities in the gut.

Question 15

Hoe much bacteria is in our gut

Answer 15

There are trillions of useful bacteria in out gut (intestine).

Question 16

What are mutualistic bacteria?

Answer 16

Bacteria in the gut are described as mutualistic bacteria because they benefit from us and we benefit from them

Question 17

Mutualism definition

Answer 17

Mutualism is when two organisms live in close association and both of them benefit from the arrangement.

Question 18

List the benefits of mutualistic bacteria in the gut

Answer 18

They can help to digest some foods.
They produce vitamin B (for energy) and vitamin K (for clotting of blood).
They prevent harmful bacteria from surviving in the gut (the sheer numbers of good bacteria prevent the harmful bacteria ones from increasing in population).
They boost our immune system by keeping harmful populations of bacteria under control.

Question 19

Probiotics definition

Answer 19

Probiotics are living organisms that improve human health

Question 20

Example of a probiotic for the human gut

Answer 20

Lactobacillus acidophilus

Question 21

What do fungi and bacteria have in common?

Answer 21

They are decomposers that break down desd matter to substances such as carbon and nitrogen compounds. These compounds are then recycled back into living organisms through photosynthesis and nitrates from the soil

Question 22

Name some fungi that cause minor health problems for humans. What can they be treated with

Answer 22

Athletes foot and ringworm can be treated with antifungal medicines.

Question 23

Why are fungi very important for human health

Answer 23

Fungi provide powerful medicines e.g. medicines to control cholesterol (statins)

Question 24

What is penicillin and other antibiotics based on

Answer 24

They are based on natural chemical produced by fungi

Question 25

What can overuse of antibiotics lead to?

Answer 25

overuse of antibiotics can lead to resistant forms of bacteria

Question 26

What is food spoilage caused by?

Answer 26

Food spoilage is caused by bacteria and fungi

Question 27

Explain 6 different food preservation methods

Answer 27

1. Refrigeration: the temperature is too low for microorganisms to grow.
2. Freezing: there is no water available to the microorganisms so they cannot work.
3. Pickling: the acidity of the vinegar destroys microorganisms.
4. Salting and syrup: the salt of sugar draws water out of the microorganisms and they die.
5. Drying: there us no water so microorganisms cannot survive.
6. Pasteurisation: the food (e.g. milk/orange juice) is heated to a high temperature in order to kill microorganisms.