infection and response

Question 1

What are pathogens?

Answer 1

Microorganisms that transmit infectious diseases

Question 2

What are the types of pathogens?

Answer 2

-Bacteria

-Viruses

-Fungi

-Protists

Question 3

How does direct contact transmit disease?

Answer 3

-Sexual contact

-Touching

Question 4

How does water transmit disease?

Answer 4

Dirtty water can transmit diseases such as cholera

Question 5

How does air transmit disease?

Answer 5

Sneeze droplets contain virus particles

Question 6

How does food transmit disease?

Answer 6

Undercooked or reheated food can cause E-coli

Question 7

How do vectors transmit disease?

Answer 7

Organisms such as mosquitos transmit diseases such as malaria

Question 8

How do bacteria cause illness?

Answer 8

Bacteria produces toxins that damages tissue and cause illness

Question 9

How do viruses cause cause illness?

Answer 9

Viruses live and reproduce inside cells, causing cell damage

Question 10

What are phagocytes?

Answer 10

White blood cells that engulf pathogens in a membrane which destroys the pathogen with enzymes

Question 11

What are lymphocytes?

Answer 11

White blood cells that recognise antigens on the pathogens’ surfaces and produce antibodies that cause pathogens to stick together to be engulfed by phagocytes. They also produce antitoxins to neutralise pathogen toxins

Question 12

How does sterilisation prevent the spread of disease?

Answer 12

Chemicals or UV light kill pathogens in water such as cholera

Question 13

How does food hygiene prevent the spread of disease?

Answer 13

Cooking foods thoroughly and preparing them in hygienic conditions kills pathogens

Question 14

How does vaccination prevent the spread of disease?

Answer 14

Vaccinations introduce weak versions of the pathogen to your body so it can learn how to fight it

Question 15

How does contraception prevent the spread of disease?

Answer 15

Condoms stop the transfer of bodily fluids and the disease

Question 16

How does skin defend against pathogens?

Answer 16

It covers the body to stop pathogens from entering. When damaged, it heals itself with scabs.

Question 17

How do eyes defend against pathogens?

Answer 17

Tears contain enzymes which can destroy pathogens

Question 18

How does the nose defend against pathogens?

Answer 18

Hairs trap pathogens and cells produce mucus to trap pathogens

Question 19

How do the trachea and bronchi defend against pathogens?

Answer 19

The trachea is lined with cilia which move mucus and pathogens to the throaty where they are swallowed to the stomach

Question 20

How does the stomach defend against pathogens?

Answer 20

Hydrochloric acid kills pathogen

Question 21

Explain the features of measles

Answer 21

PATHOGEN: virus

ORGANISM AFFECTED: humans

TRANSMISSION: inhalation of sneeze/ cough droplets

SYMPTOMS: fever and red skin rash, can be fatal

TREATMENT/PREVENTION: vaccines

Question 22

Explain the features of tobacco mosaic virus

Answer 22

PATHOGEN: virus

ORGANISM AFFECTED: plants such as tomatoes

TRANSMISSION: contact

SYMPTOMS: discoloured spots which prevent photosynthesis

TREATMENT/PREVENTION: no cure so farmers must attempt to reduce the spread

Question 23

Explain the features of HIV

Answer 23

PATHOGEN: virus

ORGANISM AFFECTED: humans

TRANSMISSION: transfer of bodily fluids (sexual contact/sharing needles)

SYMPTOMS: initially flu-like, late stage HIV becomes AIDS and badly damages trhe body

TREATMENT/PREVENTION: using condoms, not sharing needle, antiretroviral drugs

Question 24

Explain the features of salmonella

Answer 24

PATHOGEN: bacteria

ORGANISMS AFFECTED: humans

TRANSMISSION: unhygienic food

SYMPTOMS: fever, abdominal cramps, vomiting, and diarrhoea

TREATMENT/PREVENTION: poultry vaccination

Question 25

Explain the features of gonorrhoea

Answer 25

PATHOGEN: bacteria ORGANISMS AFFECTED: humans TRANSMISSIONS: STD SYMPTOMS: yellow or green discharge, pain, and infertility TREATMENT/PREVENTION: antibiotic penicillin, condoms

Question 26

Explain the features of malaria

Answer 26

PATHOGEN: protists ORGANISMS AFFECTED: humans TRANSMISSIONS: mosquito bites SYMPTOMS: fever, can be fatal TREATMENT/PREVENTION: mosquito nets

Question 27

Explain the features of rose black spot

Answer 27

PATHOGEN: fungus ORGAMISMS AFFECTED: roses TRANSMISSION: wateer or wind SYMPTOMS: purple or black spots which turn yellow and leaves drop affecting photosynthesis TREATMENT/PREVENTION: fungicides and destroying affected leaves

Question 28

What is herd immunity?

Answer 28

Vaccinating a population against a specific disease

Question 29

What is digitalis?

Answer 29

A heart drug made from foxgloves

Question 30

What is asprin?

Answer 30

A painkiller from willows

Question 31

What is penicillin?

Answer 31

An antibiotic from mould

Question 32

What are new drugs tested for?

Answer 32

TOXICITY: harmful side effects EFFICACY: how well the drug wworks DOSAGE: to make sure it works but is not a dangerous amount

Question 33

What are the stages of drug testing?

Answer 33

1. The drugs are tested using computer models and human cells grown in the laboratory. This allows the efficacy and possible side effects to be tested. Many substances fail this first test of a preclinical drug trial because they damage cells or do not seem to work. 2. Drugs that pass the first stage are tested on animals in the second part of a preclinical drug trial. In the UK, new medicines have to undergo these tests. But it is illegal to test cosmetics and tobacco products on animals. A typical test involves giving a known amount of the substance to the animals, then monitoring them carefully for any side-effects. 3. Drugs that have passed animal tests are used in human clinical trials. They are tested on healthy volunteers to check that they are safe. The substances are then tested on people with the illness to ensure that they are safe and that they work. Low doses of the drug are used initially, and if this is safe the dosage increases until the optimum dosage is identified.

Question 34

What is the placebo effect?

Answer 34

Feeling better despite the drug having no real physical effect

Question 35

How is the placebo affect reduced?

Answer 35

Double blind trials which include neither doctors nor patients knowing which drugs are real and which are placebo so researchers can tell the effects

Question 36

Explain the monoclonal antibody process

Answer 36

Mouse is vaccinated to start antibody formation > cells are collected from the mouse in surgery > cells are fused with myeloma cells (tumour cells) > forms hybridoma cells > grown in a lab > those which produce antibodies are separated > antibodies are collected and purified

Question 37

What are monoclonal antibodies used for?

Answer 37

-Pregnancy tests -Measuring blood hormone levels -To locate molecules in cell tissue with fluorescent dye To treat diseases such as cancer

Question 38

What features suggest plant disease?

Answer 38

-Stunted growth -Leaf spots -Decay -Growths -Malformed stems -Discolouration -Pests