Chapter 7 Set 1

Question 1

What is a pathogen?

Answer 1

A disease-causing organism.

Question 2

What are the different types of pathogens?

Answer 2

Bacteria
Viruses
Fungi, Protozoa

Question 3

What is an infectious disease and an example?

Answer 3

A disease caused by pathogens.
E.g. A skin infection after injury is infectious but doesn’t pass on to other people. Tetanus is infectious and can be acquired from a penetrating skin injury as the bacteria lives in soil, but is not communicable. If you have tetanus, you can’t directly pass it on to anyone else.

Question 4

What are contagious diseases?

Answer 4

Infectious diseases that can be passed from one person to another.

Question 5

Describe the relative sizes of pathogens to a blood cell and each other.

Answer 5

Viruses are smaller than bacteria. Both are smaller than blood cells.

Question 6

Describe a Bacteria:
- Are all harmful?
- Where are they found?
- Are they multi/uni cellular?
- How can they be seen?
- Prevented with?
- Treated with?

What are two examples?

Answer 6

Most are harmless.
Found everywhere including skin
They are unicellular
They can be seen using a light microscope
They can be prevented with vaccines
They can be treated with antibiotics

Two examples of bacterial pathogens include Salmonella, and Syphilis

Question 7

Describe Viruses:
- How can they be seen?
- What are they made of?
- How do they reproduce?
- Are all harmful?
- Can they be treated with antibiotics?

What are two examples?

Answer 7

They can be seen only with an electron microscope
They are made of genetic material e.g. DNA/RNA surrounded by a protein coat
They enter cells and use their DNA/RNA to infiltrate cell processes to reproduce
Not all are harmful
Cannot be treated with antibiotics rather use antivirals.

Two examples include: Covid-19 and Influenza virus

Question 8

What are two examples of fungi and animal parasites?

Answer 8

Fungi:
- Ringworm
- Tinea

Parasites:
- Malaria
- Ticks

Question 9

What are the 5 main methods of transfer of pathogens?

Answer 9

• Contact:
  Direct: by touching an affected person and the pathogen transfers directly eg. ringworm
  Indirect: By touching something an infected person has touched.
• Transfer of Body Fluids
  e.g. Blood, Semen, Mucus, Faeces, Urine
• Droplet/Airborne Infection
  Pathogens spread by coughing/sneezing as droplets of mucus containing the pathogens fly through the air and are inhaled or ingested.
• Ingestion
• Transmission by Vector
  “vector” is another organism that carries the disease from one person to another
  e.g. Mosquitoes