Cells and the Immune System - The Immune System

Question 1

What Trigger an Immune Response?

Answer 1

Antigens.

Question 2

Where are Antigens found?

Answer 2

Antigens are found on the surface of cells.

Question 3

What are Antigens used to Identify by the Immune System?

Answer 3

Pathogens, abnormal body cells, toxins and cells from other individuals of the same species.

Question 4

How many (Main) Stages are apart of the Immune Response?

Answer 4

Four main stages.

Question 5

What is the First Main Stage of the Immune Response?

Answer 5

Phagocytes engulf pathogens.

Question 6

What are Phagocytes?

Answer 6

A phagocyte, for example a macrophage, is a variant of white blood cell that carries out phagocytosis.

Question 7

What are Lysosomes?

Answer 7

Lysosomes are organelles that contain lysozymes, a type of enzyme.

Question 8

What is the Second Main Stage of the Immune Response?

Answer 8

Phagocytes activate T-cells (T-lymphocytes), which are another type of white blood cell.

Question 9

What are T-cells (T-lymphocytes)?

Answer 9

A type of white blood cell that has receptor proteins on its surface that bind to complementary antigens on a specific pathogen.

Question 10

What are Two Examples of T-cells?

Answer 10

Helper T-cells, and Cytotoxic T-cells.

Question 11

How do Helper T-cells respond to Pathogens?

Answer 11

Helper T-cells release chemical signals that activate and stimulate phagocytes and cytotoxic T-cells.

Question 12

How do Cytotoxic T-cells Respond to Foreign Cells?

Answer 12

They kill abnormal and foreign cells by inducing apoptosis.

Question 13

What are B-cells (B-lymphocytes)?

Answer 13

B-cells (which are activated by helper T-cells) secrete antibodies and divide into plasma cells.

Question 14

What are found on the Surface of B-cells?

Answer 14

Antibodies.

Question 15

What do Antibodies do?

Answer 15

Antibodies are proteins that bind to antigens to form an antigen-antibody complex.

Question 16

What happens when the Antibody on the Surface of a B-cell meets a Complementary Antigen?

Answer 16

It binds to it, and this combined with substances released from helper T-cells activates the B-cell. This is called clonal selection, and the activated B-cell divides into plasma cells.

Question 17

What are Plasma Cells?

Answer 17

Plasma cells are identical to B-cells. They secrete many antibodies for a specific antigen.

Question 18

What are the Antibodies Produced by Plasma Cells known as?

Answer 18

Monoclonal antibodies.

Question 19

What is Agglutination?

Answer 19

Antibodies have two binding sites, so it can bind to two pathogens at the same time. This results in pathogens clumping together.

Question 20

Why is Agglutination Important?

Answer 20

Since many pathogens end up clumped together, it’ll be easier for macrophages to phagocytose many pathogens at once, resulting in the destruction of this specific pathogen.

Question 21

What are Antibodies?

Answer 21

Antibodies consist of amino acid chains. The specificity of it depends on variable regions, which form the antigen binding sites.

Question 22

What is the Variable Region on an Antibody?

Answer 22

Each antibody has a variable region, with a unique tertiary structure that is complementary to one specific antigen.

Question 23

What is the Same for all Antibodies?

Answer 23

The constant region is the same for all antibodies.

Question 24

What are the Two Types of Immune Response?

Answer 24

Cellular and humoral.

Question 25

What forms the Cellular Immune Response?

Answer 25

The T-cells, and other immune system cells they interact with (for example, phagocytes), form the cellular response.

Question 26

What forms the Humoral Immune Response?

Answer 26

B-cells, clonal selection, and the production of antibodies forms the humoral response.