Microorganisms

Question 1

Define a microorganism?

Answer 1

• Microscopic organism –> have to use a microscope.
• Mostly unicellular.
• Includes: bacteria, fungi, protozoa, algae and viruses.

Question 2

What is protozoa?

Answer 2

Malaria caused by plasmodium spp.

• transmitted by mosquito.
• complex lifespan.
• infects red blood cells.

Question 3

What is another protozoa?

Answer 3

Entamoeba histolytica –> causes diarrhoea or amoebic dysentery.

• transmitted from eating/drinking something contaminated with infected faeces.

Question 4

What are fungi’s?

Answer 4

Organisms that grow by decomposing and absorbing material.

• non motile –> don’t move.

Question 5

How is fungus classified?

Answer 5

Based on their structure.

Question 6

What do fungi use to reproduce?

Answer 6

Spores (single cells)

Question 7

Do fungi always cause harm?

Answer 7

Not always, not always pathogenic.

Question 8

What are the classification for bacteria shapes?

Answer 8

1) . Bacilli (rod shaped).
2) . Cocci (sphere).
3) . Spiral.

Question 9

What are the classifications for the bacteria clusters?

Answer 9

1) . Diplo (2 joined).
2) . Strepto (chains).
3) . Staphylo (grapelike cluster).

Question 10

How are bacteria classified via their colour?

Answer 10

1) . Gram positive (purple/blue).

2) . Gram negative (pink/red).

Question 11

What is an example of bacteria when the classifications are put together?

Answer 11

1). Staphylococcus =

• grapelike cluster.
• sphere.

2). Streptococcus =

• chains.
• sphere.

Question 12

How do bacteria divide?

Answer 12

Binary fission –> doubling their number.

Question 13

Is binary fission a sexual or asexual process?

Answer 13

Asexual.

Question 14

What is binary fission?

Answer 14

Where bacteria can divide, double their size and replicate their chromosome.

Question 15

What is bacteria spore formation?

Answer 15

• When vegetative form of bacteria experience unfavourable conditions.
• Spores are resistant; to extreme temperatures and many chemicals.

Question 16

Why do bacteria form spores?

Answer 16

Because bacterial spores can withstand many conditions, keeping the bacteria alive.

Question 17

What are commensal organisms?

Answer 17

Bacteria benefit from the host =

• host isn’t harmed.
• organism could be a pathogen if it enters another area of the body.

Question 18

What is normal flora?

Answer 18

Populations of organisms that live in various parts of the body, but do not cause disease.

Question 19

What is mutualism?

Answer 19

When both host and microorganism benefit.

Question 20

What is an example of mutualism?

Answer 20

Lactobacillus =

• maintains the pH of the vagina.
• inhibits growth of potentially harmful fungi which causes thrush.

Question 21

What are the characteristics of viruses?

Answer 21

• Smaller than bacteria.
• Contains small amount of nucleic acid.
• May be enveloped (lipid/protein structure) or non-enveloped.
• Different shapes.
• Uses its host to replicate and cannot replicate outside of host cells.

Question 22

What is the protective protein coat of a virus called?

Answer 22

Capsid.