Pathogens

Question 1

Define what a pathogen is.

Answer 1

A pathogen is a foreign substance that is a disease-causing organism.

Question 2

What are the different types of pathogens?

Answer 2

1. Bacteria
2. Viruses
3. Fungi
4. Parasites

Question 3

Describe what a bacteria is

Answer 3

Bacteria are prokaryotes, unicellular organisms with a simple internal structure. They lack nuclues and DNA feely floats in the cytoplasm in the form of circular plasmids.

Question 4

What are the different structures of a prokaryote?

Answer 4

1. Slime layer
2. Cell membrane
3. Cell wall
4. Flagella
5. DNA
6. Cytoplasm
7. Capsule

Question 5

What is the slime layer?

Answer 5

Around the outside of some bacteria.

Question 6

What is the cell membrane?

Answer 6

Separates the cell from neighbouring cells and the external environment.

Question 7

What is the cell wall?

Answer 7

The cell wall composition varies. It is often made of peptidoglycan, a combined carbohydrate-protein.

Question 8

What is the flagella?

Answer 8

The flagella are used for movement. It is not found on all bacteria.

Question 9

How is DNA maintained in a prokayote?

Answer 9

There is no nuclear membrane so the DNA forms a tangle inside the cell. Some DNA is in the form of plasmids that can be exchanged during replication.

Question 10

What is the cytoplasm?

Answer 10

The cytoplasm appears granular due to the presence of ribosomes. BActeria do not have membrane bound organelles.

Question 11

What is the capsule?

Answer 11

The capsule is formed of complex carbohydrates by some bacteria for protection.

Question 12

How do bacteria reproduce?

Answer 12

Bacteria reproduce through a process called binary fission. It involves the parent prokaryotic cell’s DNA to replicate and grow to twice its size and then split into two identical daughter cells.

Question 13

How do bacteria make you sick?

Answer 13

Bacteria can produce toxins or induce an allergic response. These toxins are powerful chemicals that damage cells and make you ill.

Question 14

What are some examples of bacteria?

Answer 14

1. Anthrax
2. Leprosy
3. Chalmydia

Question 15

How are bacteria transmitted?

Answer 15

• Infected droplets
• Airborne Transmission

Question 16

Describe what a virus is.

Answer 16

A virus is an infectious agent consisting of a protein sheath surrounding a core of nucleic acid. Viruses are totally dependent on living cells for reproduction.

Question 17

What is the difference between some viruses’ structures?

Answer 17

Viruses all contain a core of nucleic acid but not both. Nucleic acid can be surrounded by a protein coat or a lipid outer membrane. Some viruses consist of an additional envelope of lipid and protein molecules called a lipoprotein envelope.

Question 18

How do viruses reproduce?

Answer 18

Viruses cannot reproduce by themselves. They attach to the outside of a host cell and the nucleic acid enters the cell. New viral genes are produced by the host cell and so hundreds of new virus particles are formed.

Question 19

How do viruses make you sick?

Answer 19

Viruses take over the body’s cells. They will kill and disrupt the cell’s functions.

Question 20

What are some examples of viruses?

Answer 20

1. HIV/AIDs
2. Chicken Pox
3. COVID-19

Question 21

How are viruses’ transmitted?

Answer 21

• Airborne transmission
• Physical contact
• Transmission of body fluids
• Infection by droplets.

Question 22

Define Bacteriophage

Answer 22

A virus that infects bacteria.

Question 23

Define infectious disease

Answer 23

A disease passed from one person to another by infection with micro organisms.

Question 24

How else are infectious diseases known as?

Answer 24

• Transmissible disease
• Communicable disease

Question 25

Define plasmid

Answer 25

Are smaller circular strands of DNA distinct from the main bacterial genome.

Question 26

Identify three characteristics of viruses that help to classify them as non-cellular pathogens.

Answer 26

1. Not comprised of cells.
2. Reproduce outside of the host cell.
3. Does not carry out metabolic processes.