Pathogens and immune system in Humans

Question 1

What are pathogens?

Answer 1

Organisms that cause disease

Question 2

What are the four types of pathogen?

Answer 2

Fungi
Protoctists
Bacteria
Viruses

Question 3

Describe the common features shown by prokaryotic organisms such as bacteria

Answer 3

prokaryotic cells are cell without a nucleus but with DNA in a loop of DNA - plasmid circular chromosome

Question 4

Understand how the immune system responds to disease using white blood cells

Answer 4

2 types of white blood cell work together to destroy pathogens
Lymphocytes - produce antibodies that stick to pathogens and disable them
Phagocytes - engulf and digest pathogens using enzymes. Can also destroy pathogens disabled by lymphocytes

Question 5

What are bacteria?

Answer 5

microscopic single-celled organisms
- cell wall, cell membrane, cytoplasm
no nucleus but contain a circular chromosome of DNA
e.g. pneumococcus - pneumonia

Question 6

What are viruses?

Answer 6

All pathogens - all cause disease
Non-living
No cytoplasm or cell membrane
Genetic material - DNA/RNA
Protein coat
e.g. HIV virus, common cold