Infection and Response

Question 1

What are the 4 disease-causing pathogens ?

Answer 1

Viruses, Protists, Bacteria, Fungi

Question 2

What is a pathogen ?

Answer 2

Microorganisms that cause infectious diseases

Question 3

How can pathogens be spread ?

Answer 3

• Direct Contact
• Air
• Water
• Vectors

Question 4

What is a Vector ?

Answer 4

an organism that carries a pathogen and can pass it on but is not infected

Question 5

How can the spread of pathogens be prevented ?

Answer 5

• good hygiene
• destroying or controlling vectors
• isolating infected individuals
• vaccinations

Question 6

What are Viruses ?

Answer 6

Viruses are very small particles capable of infecting every type of living organism.

Question 7

Types of Viral Pathogens

Answer 7

• Measles
• HIV
• Tobacco Mosaic Virus (TMV)

Question 8

How do bacteria pathogens cause disease ?

Answer 8

They divide rapidly by splitting in two. They may produce toxins that affect your body and make you feel ill.

Question 9

How do virus pathogens cause disease ?

Answer 9

Viruses take over the cells of your body. They live and reproduce inside the cells, damaging and destroying them

Question 10

Salmonella

Answer 10

• spread in food bacteria and caused by unhygienic kitchen environment.
• all chickens are vaccinated against it

Question 11

Gonorrhoea

Answer 11

• used to be treated by penicillin
• treated by antibiotics
• wear a condom
• get tested and vaccinated to prevent spread

Question 12

Measles

Answer 12

• it is a virus

- spread in droplets when someone coughs or sneezes

Question 13

HIV

Answer 13

• can be treated by antiretroviral drugs which stop virus multiplying which stop it from going onto to develop AIDS
• drugs not a cure but has to be taken for the rest of your life

Question 14

Malaria

Answer 14

• bouts of fever
• protist
• stop vector from breeding by draining or insecticide areas of still water
• use a mosquito when sleeping to stop mosquito from entering.

Question 15

Antibodies

Answer 15

• produced by lymphocytes
• lymphocytes produce antibodies against anything foreign
• scientists call foreign objects like this antigens

Question 16

Monoclonal Antibodies

Answer 16

• Inject mouse with antigen then lymphocytes will produce antibodies against the antigen
• Collect lymphocytes from mouse
• They don’t divide by mitosis so they fuse with tumour cell which are very good are dividing by mitosis
• This produced a hybridoma cell
• Select a single hybridoma cell with the antibody we want
• Allow division to form clones which are identical

Question 17

Monoclonal Antibodies are….

Answer 17

specific to one binding site or one antigen

Question 18

Pregnancy Test

Answer 18

• it detects a specific hormone
• cheap and easy to use
• highly accurate

Question 19

Lab Testing

Answer 19

• measure levels of hormones in blood

- detect pathogens in blood

Question 20

Locating MAB

Answer 20

locate or identifying specific molecules

Question 21

Treating Diseases

Answer 21

• specific to cancer cells
• attach radioactive substance or toxic drug to the antibody
• which attaches to cancer cell and stop it from growing and dividing

Question 22

Testing Medicines

Answer 22

toxicity , efficacy and dosage

Question 23

Foxglove

Answer 23

digitalis

Question 24

Willow Tree

Answer 24

aspirin

Question 25

Preclinical Testing

Answer 25

- carried out on cells, tissues and live animals

Question 26

Clinical Testing

Answer 26

- very low doses given to healthy volunteers | - to test for dosage

Question 27

Placebo

Answer 27

a tablet or injection with no active drug in it

Question 28

Double - blind trial

Answer 28

- test group receive active drug - Placebo group receive a dummy drug but not active - neither doctors nor patients know which people have the placebo and active drug to stop bias

Question 29

Nitrate Deficiency

Answer 29

Plants use nitrates as a supply of nitrogen, which is needed to make proteins for healthy growth. Without nitrates, the amount of chlorophyll in leaves reduces. This means leaves turn a pale green or yellow colour. This reduces the plant's ability to photosynthesise and grow properly.

Question 30

Magnesium Deficiency

Answer 30

Plants use magnesium ions to make chlorophyll in their leaves. Like in nitrate deficiency, the plant is limited in terms of its photosynthetic ability and the plant growth is compromised.

Question 31

Symptoms of Infection in Plants

Answer 31

- Stunted growth from mealybugs - Spots on leaves caused by the rose black spot fungus - Decay caused by the rice blast fungus - Malformed stems or leaves caused by the ash dieback fungus - Discoloration caused by the tobacco mosaic virus - The present of pests (aphids)

Question 32

Physical Defences

Answer 32

- thick bark - cellulose cell wall - leaves covered with a waxy cuticle

Question 33

Chemical Defences

Answer 33

- mint and witch hazel produce antibacterial chemicals. | - stinging nettles, have developed poisons to stop themselves being eaten by herbivores

Question 34

Other defences

Answer 34

Farmers can now genetically engineer crop plants to be resistant to infections.

Question 35

Mechanical Defences

Answer 35

- Thorns and hairs - Drooping leaves - evolved to close its leaves and then point its stems towards the ground when touched by an insect - Mimicry - Some plants have evolved the ability to mimic what is around them