Infection and Response - paper 1

Question 1

What is a pathogen?

Answer 1

A microorganism that causes infectious disease. They can infect plants and animals.

Question 2

What are the four types of pathogen?

Answer 2

Bacteria, viruses, protists, fungi.

Question 3

What are the 4 ways pathogens can be spread?

Answer 3

1. Particles in the air (coughing, sneezing) 2. Water 3. Food 4. Direct contact.

Question 4

How can the spread of diseases be prevented?

Answer 4

General hygiene, killing vectors, isolation of infected individuals, and vaccination.

Question 5

How do bacteria make us ill?

Answer 5

Once they enter the body, they reproduce very quickly and produce toxins that damage tissue.

Question 6

How do viruses make us ill?

Answer 6

Live and reproduce inside cells, causing cell damage.

Question 7

Describe measles.

Answer 7

A viral disease characterized by fever and red skin rash, spread by droplets in the air.

Question 8

Describe HIV.

Answer 8

A viral disease with flu-like symptoms that attacks the immune system, spread by sexual contact or unhygienic needles.

Question 9

Describe TMV.

Answer 9

A viral disease that causes a mosaic pattern on leaves, stunting growth, spread by direct contact.

Question 10

Describe salmonella.

Answer 10

A bacterial disease causing fever, abdominal cramps, and vomiting, spread by food prepared in unhygienic conditions.

Question 11

Describe gonorrhoea.

Answer 11

A bacterial disease with thick yellow or green discharge and pain urinating, sexually transmitted.

Question 12

Describe rose black spot.

Answer 12

A fungal disease with purple/black spots on leaves causing stunted growth, spread by water or wind.

Question 13

Describe malaria.

Answer 13

A protist disease that is feverous and can be fatal, spread by the vector mosquitos.

Question 14

What are the 4 human defense mechanisms?

Answer 14

1. Skin (physical barrier) 2. Nose (mucus) 3. Trachea and bronchi (mucus, cilia) 4. Stomach (HCl kills pathogens).

Question 15

What are the 3 things that white blood cells do?

Answer 15

1. Phagocytosis (engulf pathogens) 2. Produce antitoxins (counteract toxins) 3. Produce antibodies (acts as a signal and memory cells).

Question 16

How do vaccinations work?

Answer 16

A small quantity of dead or inactive pathogens enters the body, stimulating WBC to make antibodies.

Question 17

What is herd immunity?

Answer 17

Immunizing a large proportion of the population reduces the spread of infection.

Question 18

What do antibiotics do?

Answer 18

They kill bacteria in the body, and it’s important that specific bacteria are treated by the correct antibiotics.

Question 19

Why is it difficult to treat viruses?

Answer 19

Viruses are inside the host cell, making it hard to kill them without affecting the body’s tissues.

Question 20

What did foxgloves create?

Answer 20

Digitalis (a heart drug) was extracted from foxgloves.

Question 21

Where did aspirin come from?

Answer 21

Willow bark.

Question 22

Who created penicillin?

Answer 22

Alexander Flemming accidentally created penicillin from mould.

Question 23

What are the stages of developing a drug?

Answer 23

1. Preclinical - tested in a lab on cells, tissues, and animals 2. Clinical - low dosage given to healthy volunteers.

Question 24

What 3 things are being tested for in preclinical trials?

Answer 24

1. Efficacy (how well it works) 2. Toxicity (how harmful it is) 3. Dosage (how much is required).

Question 25

What is a double blind trial?

Answer 25

Neither the patients nor the doctor know whether the drug being given is real or a placebo.

Question 26

What is a monoclonal antibody?

Answer 26

An antibody specific to one binding site for one antigen, produced from a single clone of cells.

Question 27

What is a hybridoma cell?

Answer 27

A hybridoma cell is formed from a lymphocyte and a tumour cell, capable of dividing and making antibodies.

Question 28

What is the result of a magnesium deficiency in plants?

Answer 28

Chlorosis (discolouration).

Question 29

What is the result of a nitrate deficiency?

Answer 29

Stunted growth.

Question 30

What are the physical defence mechanisms on a plant?

Answer 30

Cellulose cell walls, waxy cuticles, bark.

Question 31

What are the chemical defence mechanisms on a plant?

Answer 31

Antibacterial chemicals, poisons.

Question 32

What are the mechanical defence mechanisms on a plant?

Answer 32

Thorns, hairs, leaves that droop when touched, mimicry.

Question 33

How can plant diseases be identified?

Answer 33

1. Reference to a gardening manual or website 2. Laboratory testing 3. Using testing kits with monoclonal antibodies.

Question 34

What might indicate that a plant has a disease?

Answer 34

1. Stunted growth 2. Spots on leaves 3. Areas of decay 4. Presence of pests 5. Discolouration 6. Malformed stems and leaves 7. Growths.

Question 35

What are aphids?

Answer 35

Small insects that feed from phloem, taking sugars from plants, which stunts growth.

Question 36

What are monoclonal antibodies used for?

Answer 36

1. Pregnancy tests 2. Measuring hormone levels, chemicals, or pathogens 3. Researching specific molecules 4. Treating diseases.

Question 37

What are the disadvantages of monoclonal antibodies?

Answer 37

They create more side effects than expected and are not yet widely used.

Question 38

How can monoclonal antibodies treat cancer?

Answer 38

They bind to a radioactive substance which stops cancer cells from growing and dividing.