Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Cell recognition and the Immune system > Flashcards

Cell recognition and the Immune system Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Name some of the bodies defence mechanisms against pathogens

A

Physical and chemical defences, Inflammation (swelling and heating) and recognising foreign cells known as ‘specific immune response’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Give examples of physical defences

A

Skin and Mucus Membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give examples of chemical defences

A

Tears, saliva and sweat containing lysozyme, destroys bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the name given to the bodies own cells

A

self

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the name given to foreign cells

A

non-self

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can the body recognise foreign cells

A

Due to specific molecules located on the surface of cells (usually proteins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What contains the surface molecules to be recognised as foreign

A

Pathogenic cells, abnormal body cells, toxins, cells from individuals from the same species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are these surface molecules known as

A

Antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give an example of abnormal body cells

A

Cancerous or pathogen infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What form are toxins in

A

Chemical rather than cellular. (Released by bacteria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Give an example of when cells from other individuals may enter the body

A

Organ transplants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do antigens allow for

A

cell-to-cell recognition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where do eukaryotes contain their antigens

A

Cell membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where do prokaryotes contain their antigens

A

Cell walls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What can also act as antigens on cell surface membranes

A

Glycolipids and Glycoproteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the two forms of antigen

A

Self antigens or Non-self antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is antigen variability

A

Antigens present on the surface changing frequently due to genetic mutations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Do some pathogens exhibit genetic variability

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does genetic variability pose as a problem for the immune system

A

Lymphocytes and memory cells produce one specific immune response. Therefore, the surface receptors are complementary in shape to just one antigen. When the antigen changes the lymphocyte and memory cells can no longer bind. So, no secondary immune response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Give examples of common pathogens that exhibit antigen variability

A

The cold virus and influenza virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the two main types of phagocyte

A

Neutrophils and Macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the role of phagocytes

A

To recognise and engulf pathogens (phagocytosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are phagocytes and where are they produced

A

White blood cells. Produced in bone marrow

24
Q

What is the 1st step of phagocytosis

A

Chemicals released by pathogens, as well as chemicals released by body cells e.g. histamines, attract phagocytes. (Chemotaxis)

25
Q

What is the 2nd step of phagocytosis

A

Phagocytes move toward the site of infection, where pathogens can be identified due to antigens. Phagocytes have receptor proteins on surface to recognise pathogens as non-self.

26
Q

What is the 3rd step of phagocytosis

A

The phagocyte attaches to the pathogen by binding to its antigens. Once attached the cell surface membrane of the phagocyte extends our and around the pathogen engulfing it. (Endocytosis)

27
Q

What is the phagocytic vacuole formed when the phagocyte engulfs the pathogen called

A

Phagosome

28
Q

What is the 4th step of phagocytosis

A

The phagocytic vacuole fuses with a lysosome to form a phagolysosome. The lysosome releases digestive enzymes called lysozymes e.g. by hydrolysis of bacterial cell walls.

29
Q

What is a lymphocyte

A

Another type of white blood cell

30
Q

Which is smaller lymphocytes or phagocytes

A

Lymphocytes

31
Q

What is the lymphocytes nucleus like

A

A large nucleus that fills most of the cell

32
Q

When are lymphocytes produced

A

In the bone marrow before birth (weeks 25-32)

33
Q

What are the two types of lymphocytes

A

T-Lymphocytes (T-Cells) and B-Lymphocytes (B-Cells)

34
Q

Where do immature T - Lymphocytes mature

A

They leave the bone marrow and mature in the thymus

35
Q

What do mature T - Lymphocytes have

A

T cell receptors

36
Q

What is the structure of T cell receptors similar to

A

They are similar to antibodies and are specific to one antigen

37
Q

When are T -Lymphocytes activated

A

When they bind to their specific antigen that is being presented by one of the hosts cells

38
Q

How do activated T-lymphocytes divide

A

Mitosis

39
Q

What two main types of T cell do T-Lymphocytes differentiate into

A

Helper T cells and Cytotoxic T cells (also known as killer T cells)

40
Q

What do helper T cells do

A

Assist other white blood cells in the immune response by releasing cytokines which stimulate:
The maturation of B lymphocytes
The production of memory B cells
The activation of cytotoxic T cells
An increased rate of phagocytosis

41
Q

What do T killer cells do

A

Patrol the body, attach to the foreign antigens on the cell surface membranes of infected cells and secrete toxic substances that kill the infected body cells, along with the pathogen inside.

42
Q

What do Perforins do and what are they secreted by

A

Secreted by T killer cells and punch a hole in the cell surface membrane of infected cells, allowing toxins to enter

43
Q

Where do B - Lymphocytes remain while they mature

A

In bone marrow

44
Q

Where do B - Lymphocytes go once they have matured

A

They spread through the body, concentrating in lymph nodes and the spleen

45
Q

What do B -Lymphocytes do

A

Mature the genes coding for antibodies and are changed to code for different antibodies

46
Q

What can B Lymphocyte cells do once mature

A

Each type of B lymphocyte cell can make one type of antibody molecule. At this stage, the antibody molecules do not leave the B-Lymphocyte cell but remain in the cell surface membrane.

47
Q

What does part of each antibody molecule form

A

A glycoprotein receptor

48
Q

What will happen between antigens and B - Lymphocytes if an antigen enters the body

A

B - Lymphocyte cells with the correct cell surface receptors will recognise and bind to it (clonal selection)

49
Q

How do B -Lymphocytes divide

A

Clonal expansion

50
Q

What two main types of cell do B -Lymphocytes differentiate into

A

Plasma cells and Memory cells

51
Q

what happens when an antigen enters the body for the first time

A

The small number of B-Lymphocytes with receptors complementary to that antigen are stimulated to divide by clonal expansion

52
Q

What do some of the B-Lymphocytes become after being screed in the primary response and what do they do

A

Plasma cells that secrete lots of antibodies into the blood, lymph or linings of the lungs and the gut

53
Q

How long do the plasma cells last in the primary response

A

Their numbers drop off after several weeks, but the antibodies they have secreted stay in the blood for longer

54
Q

What do other B -Lymphocytes become if they dont become plasma cells in the primary response

A

Memory cells

55
Q

is the primary response quick

A

No, it is a relatively slow response

Biology (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions