Diseases and Immunity

Question 1

Define the term “pathogen”

Answer 1

A disease-causing organism

Question 2

What is a transmissible disease?

Answer 2

A disease in which the pathogen can be passed on from one host to another

Question 3

Give the 2 ways in which a pathogen can be transmitted

Answer 3

-Direct contact - Through blood and body fluids
-Indirect contact - From contaminated surfaces, air, etc

Question 4

Describe 4 body defences

Answer 4

-Stomach acid/kills pathogens in the stomach
-Nose, Traps pathogens using mucus
-White blood cells/perform phagocytosis
-skin - creates blood clots

Question 5

What is active immunity?

Answer 5

Defence against pathogens by using antibodies in the body

Question 6

What are antibodies

Answer 6

Proteins that bind antigens together leading to destruction of antibodies

Question 7

How is active immunity gained?

Answer 7

After an infection or by vaccination

Question 8

Describe the process of vaccination

Answer 8

Weakened pathogens are put into the body
The antigens stimulate an immune response by producing antibodies
Memory cells are produced to give long-term immunity

Question 9

How do vaccinations control the spread of diseases

Answer 9

When the weakened pathogens enter the body, their antigens are recognised by the lymphocytes that make antibodies that have a complementary shape to the pathogen’s antigens. The lymphocytes multiply and produce antibodies, while also making memory cells to give long-term immunity. so if the same pathogen infects the host again, the immune system would already have ready-made antibodies to destroy it

Question 10

Why is breastfeeding important to a new-born baby?

Answer 10

The baby is provided with antibodies, by passive immunity, which help it to fight pathogens.