Micro-organisms

Question 1

What are micro-organisms ?

Answer 1

Micro-organisms ( microbes ) are very small organisms that cannot be seen with the naked eye. To see them a light microscope or if they are REALLY small , an electron microscope is needed !

Question 2

What are the types of micro-organisms we are studying ?

Answer 2

• viruses
• bacteria
• fungi
• protists

Question 3

What does pathogenic mean ?

Answer 3

Disease casing

Question 4

What does non-pathogenic mean?

Answer 4

Harmless to plants and animals

Question 5

Fun tip : many bacteria and fungi are extremely useful , life would not exists today as we know it without them

Answer 5

Fun tip : many bacteria and fungi are extremely useful , life would not exists today as we know it without them

Question 6

What are pathogens ?

Answer 6

Micro-organisms that cause disease are known as pathogens - they can commonly be called germs.

Question 7

How are germs spread ?

Answer 7

Germs cannot move on their own . They rely on being dispersed by air of fluid or being transported by a vector to get from on the host to the next

Question 8

Vector ?

Answer 8

An organism which transmits a disease but is not affected by the disease itself e.g. Mosquitoes and fleas

Question 9

Where do germs enter the body ?

Answer 9

Respiratory tract

Germs enter though month and nose when air containing germ-laden dust and moisture droplets are breathed in
Eg) diphtheria, meningococcal, meningitis, tuberculosis, influenza, measles

Gastrointestinal tract

Food containing harmful germs , not many as stomach acid kills them .

• water containing faecal matter ( typhoid and cholera)
• contaminated food ( mumps and salmonella )

Urogenital openings

STI’s and other opportunistic diseases eg - fungus causing thrush ( gonorrhea, syphilis , HIV, and E.Coli ( causing urinary tract infections )

Broken skin or mucous membrane

Skin is thick and has an acid reaction milling germs , some germs can get through unbroken skin such as wart virus

Through skin via :

• needles ( HIV , hepatitis B)
• insect bites ( malaria)
• wounds( tetanus )
• bites ( rabies)

Direct contact with delicate membranes such as :

• conjunctiva ( pink eye)
• bladder (cystitis)

Through soggy skin :

-fungal infections ( athletes foot)

Question 10

Microbes account for at least ___ percent of the total biomass of the planet

Answer 10

80

Question 11

What are the characteristics of prokaryotes?

Answer 11

• NO true nucleus
• no membrane found organelles
• DNA not enclosed by nuclear membrane , occurs freely in cytoplasm

Question 12

What are the characteristics of Eukaryotes ?

Answer 12

• true nucleus
• membrane bound organelles in cytoplasm
• DNA enclosed by a nuclear membrane ( inside nucleus )