infection and response

Question 1

What are pathogens?

Answer 1

Microorganisms that cause disease

Four types: viruses, bacteria, fungi, protists

Question 2

What are the two differences between viruses and bacteria?

Answer 2

1. Viruses are smaller than bacteria
2. Pathogenic bacteria are the minority, but all viruses cause diseases

Question 3

How do bacteria cause disease?

Answer 3

They divide rapidly (through binary fission) and produce toxins that affect the body and make you feel ill, sometimes directly damaging cells

Question 4

How do viruses cause disease?

Answer 4

They live and reproduce inside cells, damaging and destroying them

Question 5

How can pathogens be spread?

Answer 5

1. Air (e.g., coughing, sneezing)
2. Direct contact (e.g., sexual contact, vectors)
3. Water

Question 6

What are five methods to prevent the spread of communicable diseases?

Answer 6

1. Hand-washing
2. Using disinfectants on surfaces
3. Keeping raw meat away from other food
4. Isolating an infected person
5. Vaccination

Question 7

What is measles?

Answer 7

A viral disease spread by inhalation of droplets, with symptoms including fever and red skin rash, prevented by vaccination

Question 8

What is HIV?

Answer 8

A viral disease spread by sexual contact or sharing needles, with flu-like symptoms that can lead to AIDS, controlled with antiretroviral drugs

Question 9

What is the tobacco mosaic virus (TMV)?

Answer 9

A viral disease spread by plant contact or by insects as vectors, causing a mosaic pattern of discoloration on leaves

Question 10

What is salmonella?

Answer 10

A bacterial disease spread by raw food or food prepared unhygienically, causing symptoms like fever and vomiting

Question 11

What is gonorrhea?

Answer 11

A bacterial disease spread by sexual contact, characterized by yellow/green discharge, controlled with antibiotics

Question 12

What is rose black spot?

Answer 12

A fungal disease spread by wind or water, causing purple/black spots on leaves that prevent proper photosynthesis

Question 13

What is malaria?

Answer 13

A protist disease spread by vectors (mosquitos), with symptoms including fever and can lead to death

Question 14

How do the nose, trachea, and bronchi defend against pathogens?

Answer 14

They secrete mucus and have hairs or cilia that trap particles containing pathogens

Question 15

How does the skin defend against pathogens?

Answer 15

It covers the body and acts as a barrier, preventing pathogens from reaching underlying tissues

Question 16

How does the stomach defend against pathogens?

Answer 16

Acid destroys harmful microorganisms in swallowed mucus

Question 17

What are three ways that white blood cells defend against pathogens?

Answer 17

1. Phagocytosis
2. Antibody production
3. Antitoxin production

Question 18

What is phagocytosis?

Answer 18

When white blood cells ingest pathogens, digesting and destroying them using enzymes

Question 19

How do antibodies work against pathogens?

Answer 19

They bind to specific antigens on pathogens, causing them to stick together and making phagocytosis easier

Question 20

How do antitoxins work against pathogens?

Answer 20

They neutralize toxins released by bacteria

Question 21

How can aphids affect plants?

Answer 21

They feed on dissolved sugars in phloem vessels and can act as vectors transferring pathogens

Question 22

How can aphids be controlled?

Answer 22

1. Chemical pesticides
2. Releasing aphid-eating insects

Question 23

How can nitrate deficiency affect plants?

Answer 23

Growth may be stunted, as nitrates are needed for protein synthesis

Question 24

How can magnesium deficiency affect plants?

Answer 24

Without magnesium, plants cannot make chlorophyll, leading to yellowing (chlorosis) and stunted growth

Question 25

How can diseases in plants be detected?

Answer 25

1. Stunted growth 2. Spots on leaves 3. Areas of decay/rotting 4. Discoloration

Question 26

What are physical plant barriers that reduce the invasion of pathogens?

Answer 26

1. Waxy cuticle layer 2. Bark on trees

Question 27

What are chemical barriers that help protect plants against pathogens?

Answer 27

Antibacterial chemicals that can be extracted for use as antibiotics

Question 28

How can plants defend themselves from herbivores?

Answer 28

1. Being poisonous 2. Thorns 3. Mimicking unhealthy/poisonous plants

Question 29

What plant does aspirin come from?

Answer 29

Willow trees

Question 30

What is immunisation?

Answer 30

Being protected against a disease by vaccination

Question 31

How do vaccines work?

Answer 31

They contain a dead/inactivated form of the pathogen, stimulating antibody production

Question 32

What is herd immunity?

Answer 32

A large proportion of the population being immune to a disease, reducing pathogen spread

Question 33

What are antibiotics?

Answer 33

Medicines that kill infective bacteria inside the body

Question 34

What are antiseptics?

Answer 34

Chemicals that kill microorganisms outside the body

Question 35

What problem is beginning to arise with antibiotics?

Answer 35

Strains of bacteria resistant to antibiotics are evolving

Question 36

Why is it difficult to develop drugs that kill viruses?

Answer 36

Because it is difficult to kill viruses without damaging body tissues

Question 37

Where does the heart drug, digitalis, originate?

Answer 37

Foxgloves

Question 38

Who discovered penicillin?

Answer 38

Alexander Fleming

Question 39

What three aspects are drugs tested against during trials?

Answer 39

1. Toxicity 2. Efficacy 3. Dosage

Question 40

What does preclinical testing involve?

Answer 40

Testing drugs in a laboratory on cells, tissues, and live animals

Question 41

What does the first stage of clinical testing involve?

Answer 41

Testing the drug on healthy individuals for safety and side effects

Question 42

What does the second stage of clinical trials involve?

Answer 42

Testing the drug on patients to see if it treats the disease

Question 43

What is a placebo?

Answer 43

A substance that looks like the drug being tested, but has no effect

Question 44

What is a double blind trial?

Answer 44

When neither the doctor nor the patient know who is receiving the drug and who is receiving the placebo

Question 45

Why are double blind trials used in clinical trials?

Answer 45

To eliminate bias from the doctors

Question 46

What is a monoclonal antibody?

Answer 46

An identical antibody from the same immune cell, binding to one type of antigen

Question 47

How are monoclonal antibodies made?

Answer 47

B-lymphocytes are fused with tumor cells to create hybridoma cells that produce identical antibodies

Question 48

What are uses of monoclonal antibodies?

Answer 48

1. Pregnancy tests 2. Cancer treatments 3. Measuring and monitoring

Question 49

How can monoclonal antibodies be used to treat cancer?

Answer 49

They can trigger the immune system to attack cancer cells or block growth receptors

Question 50

What are the advantages of using monoclonal antibodies?

Answer 50

1. Bind to specific cells 2. Can be engineered for different conditions

Question 51

What are the disadvantages of monoclonal antibodies?

Answer 51

1. Expensive to develop 2. May trigger immune responses 3. Difficult to attach to drugs