Part 1: Pathogens and Disease

Question 1

Define ‘communicable disease’.

Answer 1

A disease that can be passed from one person to another person; caused by pathogens.

Question 2

Define ‘non-communicable disease’.

Answer 2

A disease that cannot pass from person to person; not caused by pathogens.

Question 3

Define ‘microorganism’.

Answer 3

Single-celled organisms that can only be viewed using a microscope.

Question 4

Define ‘pathogen’.

Answer 4

A microorganism that causes a disease.

Question 5

Define ‘health’. (2)

Answer 5

1. A state of physical and mental well-being.
2. An absence of disease.

Question 6

How can diet affect your health?

Answer 6

By eating too much or too little food, you can become:
• overweight
• undernourished
• at risk for the development of diseases and conditions, such as arthritis, diabetes and heart disease.

Question 7

How can stress affect your health?

Answer 7

Undealt with stress can lead to:
• high blood pressure
• heart disease
• stroke
• obesity
•type 2 diabetes

Question 8

How can life situations affect your health?

Answer 8

Increase in the risk of certain health problems in adulthood, such as:
• cancer
• heart disease
• increasing risk of mental health difficulties
• anxiety
• depression
• PTSD

Question 9

State four different types of microorganisms.

Answer 9

1. Bacteria
2. Virus
3. Fungi
4. Protoctista

Question 10

State examples of health issues caused by bacteria. (4)

Answer 10

1. Tuberculosis
2. Cholera
3. Impetigo
4. Food poisoning

Question 11

State examples of health issues caused by viruses. (6)

Answer 11

1. Measles
2. Chickenpox
3. Food poisoning
4. AIDS
5. Common cold
6. COVID-19

Question 12

State an example of health issues caused by fungi.

Answer 12

Athlete’s foot

Question 13

State an example of health issues caused by protoctista.

Answer 13

Malaria

Question 14

State the key features of a bacteria cell. (4)

Answer 14

1. No nucleus
2. May also have plasmid DNA
3. Reproduce by binary fission
4. Much smaller than animal and plant cells.

Question 15

How do bacteria cause disease? (4)

Answer 15

Once inside the cell, they…
1. Multiply rapidly
2. Damage cells
3. Release waste products or other substances that are toxic to host cells (toxins)
4. In plants, they live in vascular tissue, causing blackening and the death of these tissues.

Question 16

State the key features of a fungal cell.

Question 17

How do fungi cause disease? (3)

Answer 17

1. Fungi feed on cells,
2. Which causes damage to the tissues that they infect.
3. Some fungi may also release toxins.

Question 18

State key features of a virus. (4)

Answer 18

1. Even smaller than bacteria
2. DNA is encased in a protein coat
3. They need a host cell to reproduce.
4. Not considered alive as they don’t perform most of the MRS GREEN living processes.

Question 19

How can viruses cause disease? (3)

Answer 19

1. Viruses infect and take over host cells.
2. They cause the cell to make more copies of the virus.
3. The cells then release these virus particles, and in the process are either damaged or killed.

Question 20

State the key features of protoctista. (4)

Answer 20

1. A diverse group of organisms
2. They are eukaryotic (have a nucleus)
3. Many are unicellular organisms but include algae, seaweed, and phytoplankton.
4. Some photosynthesise while others capture food or are decomposers.

Question 21

How do protoctista cause disease? (2)

Answer 21

1. Enter host cells
2. Feed on them as they reproduce.

Question 22

Give two examples of diseases caused by protoctista.

Answer 22

1. Malaria parasite ‘Plasmodium’
2. Potato blight’s ‘phytophthora infestans’