Immunity

Question 1

What is a disease

Answer 1

A disease is a condition that prevents the body or part of the body functioning properly

Question 2

What are the two main types of white blood cell ?

Answer 2

• phagocytes

* lymphocytes

Question 3

What are phagocytes ?

Answer 3

They are type of white blood cell that engulf and Digest pathogens

Question 4

What are pathogens ?

Answer 4

Micro-organisms that cause disease

Question 5

What process occurs when a phagocytes kills a pathogen

Answer 5

Phagocytosis

Question 6

Order of phagocytosis

Answer 6

• Phagocyte recognises the pathogen
• phagocyte engulfs the pathogen in a process known as phagocytosis where it extends its cytoplasm to engulf it (pseudopodia)
• the lysozymes containing enzymes move towards the pathogen
• enzymes break down pathogen
• useful materials are absorbed, and waste products are removed from the phagocyte

Question 7

What are lymphocytes?

Answer 7

Lymphocytes are a type of white blood cell, that produce special Y shaped proteins called antibodies. These are attached to special structures on the pathogen called antigens

Question 8

Where do you find antigens ?

Answer 8

On the pathogen

Question 9

Where do you find antibodies ?

Answer 9

In a lymphocyte

Question 10

What do lymphocytes allow organisms to do ?

Answer 10

Build up immunity towards certain diseases

Question 11

Order of How lymphocytes destroy pathogens

Answer 11

• lymphocytes detect pathogen
• lymphocytes release many different types of antibody
• correct antibody connects to the pathogens antigen
• limit the site releases large number of correct antibody
—– lymphocytes can now do two things——
• pathogen is either clump together resulting into death or the antibodies trigger phagocytosis
• then lymphocytes produce cells that produce antibodies very quickly, these are called memory cells

Question 12

How long to memory cells last?

Answer 12

A lifetime

Question 13

How do you vaccines work ?

Answer 13

• The body is given a vaccine which is a dose of the pathogen normally by injection, this dose is normally a dead pathogen or part of the pathogens cell surface.
• This stops the pathogen from causing a disease
• lymphocyte generate antibodies against the pathogen and make memory cells
• this way vaccines can give us immunity

Question 14

What are the defence mechanisms for disease in the body ?

Answer 14

• lysozyme in tears
• skin
• muchus lining trachea
• urine

Question 15

Order of blood clotting

Answer 15

• injured tissues and platelets released the clotting factor - prothrombin activator and calcium ions
• prothrombin activator converts the blood protein to thrombin
• thrombin splits fibrinogen to form fibrin
• fibrin fibres form and mash over the wound, trapping red blood cells and platelets
• bleeding stops, clot hardens and become smaller
• New cells grow to repair the wound site
• enzyme plasmin is released to dissolve clot