communicable diseases,disease prevention and the immune system

Question 1

common features of bacteria?

Answer 1

A fast rate of reproduction
Treated with antibiotics
e.g bacterial meningitis

Question 2

Common features of fungi

Answer 2

Larger then bacteria
Generally live on the surfaces of organisms by growing a skin called the mycelium
Reproduce by releasing spores

Question 3

Common features of protists

Answer 3

Single celled
major protist born pathogens are Pintophoraa
and plasmodium

Question 4

common features of viruses’

Answer 4

Cannot reproduce themselves so not organism
Exceptionally small
Mutate quickly
Invade a host cell

Question 5

name transmission routes

Answer 5

Faecal oral
Direct
Airborne
Indirect
Vectoral

Question 6

Describe tuberculosis

Answer 6

A bacterial disease caused by mycobacterium
that damages lung tissue and suppresses immune system

Question 7

Describe bacterial meningitis

Answer 7

caused by bacteria streptococcus pneumonia
leads to blood poisoning or red rashes

Question 8

Describe Ring Rot

Answer 8

caused by gram positive bacteria
Damages leaves and rots tubers and fruit

Question 9

Describe HIV/AIDS

Answer 9

human immunodeficiency virus- by attacking the immune system and leads to severe illness

Question 10

Describe Influenza

Answer 10

A viral infection of the nose throat and lungs
Caused by orthomyxonious genus

Question 11

what evidence is there that antibodies have a quaternary protein structure

Answer 11

they have 4 poly peptides

Question 12

Explain why antibodies only join to specific antigens

Answer 12

antibodies have a variable region that has a specific amino acid sequence OR primary structure

the shape OR tertiary structure of the binding site is complementary to specific antigens

forms a complex between the antigen and antibody OR forms an antigen-antibody complex

Question 13

Describe how phagocytosis occurs

Answer 13

engulfs/endocytosis

forms a vesicle/phagosome AND fuses with a lysosome

enzymes/lysozymes digest/hydrolyse the pathogen

Question 14

what is an antigen?

Answer 14

a glycoprotien on the membrane
that stimultates an immune response

Question 15

During the immune response, phagocytes present a pathogen’s antigens on their cell surface.

Describe how presentation of antigens leads to the release of antibodies against these antigens.

Answer 15

helper T cell OR TH cell binds to the antigen on the phagocyte

helper T cell OR TH cell stimulates a specific B cell

B cell clones OR B cell divides by mitosis

forms plasma cells that release antibodies

Question 16

Explain how the release of antibodies stimulates the process of phagocytosis.

Answer 16

antibodies bind to antigens

OR

antibodies are markers/opsonins

OR

antibodies form antigen-antibody complexes

antibodies cause clumping/agglutination

OR

antibodies attract phagocytes

Question 17

what are the direct forms of transmission?

Answer 17

direct contact
innoculation e.g sharing needles
ingestion e.g eating infected foods

Question 18

what are the indirect forms of transmission?

Answer 18

vectors
airborne transmission
formites e.g dirty clothes

Question 19

what is autoimmune disease?

Answer 19

body produces self-recognising T cells which produce a signal of body cells as infected cells or pathogens

Question 20

describe the antibody structure

Answer 20

has two binding sites
variable regions are complementary to antigens
has four polypeptide chains called immunoglobnins

Question 21

what role does the T lymphocyte play in the immune system?

Answer 21

recognises antigens displayed on phagocytes and stimulate specific t killer cells and B cells to divide by mitosis for the specific immune response

Question 22

what are physical defences of plants?

Answer 22

waxy cuticle -forms a physical barrier
cell wall- also performs as a physical barrier
production of callose- When plants are attacked by pathogens they produce a polysaccharide called callose. This is deposited between the cell wall and the cell-surface membrane to make it harder for pathogens to enter cells.

Question 23

what are chemical defences of plants?

Answer 23

Insect repellents - These reduce the number of insects feeding on plants to prevent them from transmitting pathogens.
Insecticides - These kill insects to prevent them from transmitting pathogens.
Antibacterial substances - Chemicals such as antibiotics are produced to kill bacteria or inhibit their growth.
Toxins - Some plants produce chemicals that break down into cyanide (a toxic chemical) when the plant cells are attacked.

Question 24

what are opsonin’s?

Answer 24

they are markers for antigen presenting cells to make it easier for phagocytes to recognise a pathogen

Question 25

what are cytokines

Answer 25

released after phagocytosis which signals other phagocytes to move to the site of infection

Question 26

in the cellular response,clonal expansion means many types of T-cells describe the different types of T cells

Answer 26

T helper cells These cells have receptors on their cell-surface that bind to complementary antigens on antigen-presenting cells. They produce interleukins (a type of cytokine) which stimulate B cells or phagocytes. T helper cells can also form memory cells or T killer cells. T killer cells These cells kill abnormal and foreign cells by producing a protein known as perforin. This protein makes holes in the cell-surface membrane, causing it to become freely permeable and causing cell death. T regulator cells These cells suppress the immune system after pathogens have been destroyed. This helps to prevent the immune system from mistakenly attacking the body cells. T memory cells These cells provide long-term immunity against specific pathogens. They provide a rapid response if the body is re-infected by the same pathogen.

Question 27

what is a parasite?

Answer 27

lives , in / on , host ; gains nutrition / feeds , from (host) ; at the expense of / harms (host) ;

Question 28

explain why the body's primary defence cannot prevent infection from a parasite?

Answer 28

vector feeds on blood and breaks through the skin

Question 29

what is an antigen?

Answer 29

a glycoprotien that stimuates an immune response

Question 30

Some strains of bacteria that cause meningitis are resistant to multiple antibiotics. Discuss the consequences of this resistance for health authorities.

Answer 30

Increased further spread increased cost as it requires more complex treatment fewer antibiotics are resistant against menigitisis