B3 - Infection and Response - Cognito Notes

Question 1

What is a pathogen?

Answer 1

Microorganism that can cause disease

Question 2

What are the four pathogens?

Answer 2

bacteria, viruses, protests, fungi

Question 3

What is a communicable disease?

Answer 3

disease that can be spread from person to person

Question 4

What are some of the ways that pathogens are spread?

Answer 4

Air, contaminated food + drink, direct contact

Question 5

What are some ways that the spread of pathogens can be reduced?

Answer 5

Be hygenic, killing vectors (e.g. mosquitoes), vaccinations, isolation/quarantine

Question 6

What are viruses?

Answer 6

not living cells, can’t reproduce by themselves - only by using cell organelles which infects them

Question 7

What are some examples of viruses?

Answer 7

Measles, HIV, Tobacco mosaic virus

Question 8

What are bacteria (the bad ones)?

Answer 8

single-celled organism that can reproduce by themselves, produces toxins that damages our cells and tissues

Question 9

What are some examples of bacteria?

Answer 9

salmonella (eating contaminated food), gonorrhoea (example of STD)

Question 10

What are protists?

Answer 10

eukaryotes, either uni/multicellular, classable as parasites, often transported by vectors

Question 11

What are some examples of diseases caused by protists?

Answer 11

Malaria (caused by parasitic protists)

Question 12

What are fungi?

Answer 12

Eukaryotic, either uni/multicellular, multicellular have hyphae which can penetrate skin and cause disease

Question 13

What are some examples of diseases caused by fungi?

Answer 13

Rose black spot (causes black spots to form on plant leaves)

Question 14

What is a physical/chemical barrier?

Answer 14

Something that is physically/chemically in the way of pathogens

Question 15

What are some examples of physical/chemical barriers?

Answer 15

skin, nose hairs, mucus, stomach acid

Question 16

What is the main cell of the immune system?

Answer 16

white blood cells, which circulate in blood + tissues patrolling for pathogens

Question 17

What are the three ways that white blood cells protect us against pathogens?

Answer 17

Phagocytosis (blood cell will engulf pathogen), antibody production (binds onto pathogens, helping destroying them), antitoxin production (neutralises any toxins)

Question 18

How do vaccinations work?

Answer 18

contains a deactivated pathogen which white blood cells will produce antibodies for so when the body is infected by the same pathogen, it will attack the pathogen before it develops.

Question 19

What are the pathogens that vaccinations work against?

Answer 19

Viruses and bacteria

Question 20

What are the pros and cons of vaccinations?

Answer 20

PROS: protection from diseases, control of common diseases (e.g. polio, smallpox), prevents epidemics - CONS: don’t always work, bad reactions

Question 21

What are some examples of drugs that relieve symptoms of a disease?

Answer 21

Painkillers such as aspirin, paracetamol, cough medicine

Question 22

What are some examples of drugs that treat diseases?

Answer 22

antibiotics which can directly kill bacteria / prevent further growth

Question 23

What is the only pathogen that antibiotics work against?

Answer 23

bacteria

Question 24

What are the problems of taking too many antibiotics?

Answer 24

be weary you are taking the right ones + antibiotic resistance (some bacteria are “on the next level” and resist antibiotics)

Question 25

How are new medicines developed?

Answer 25

antigens + plants have evolved, creating new substances which can be used to develop medicines

Question 26

What are examples of some developed medicines?

Answer 26

aspirin (chemical found in willow tree bark), penicillin (fungus that grew on Flemming’s petri dish)

Question 27

What are the three things to keep in mind when testing drugs?

Answer 27

efficacy (how effective), toxicity (how harmful), dosage (how much)

Question 28

What are the preclinical stages of drug testing?

Answer 28

testing on human cells + tissues (can be grown in lab), testing on live animals (for efficacy + toxicity)

Question 29

What are the clinical stages of drug testing?

Answer 29

give to healthy volunteers with a low and slowly increasing dose (for dosage), given to someone suffering w/ illness (for optimum dosage + max efficacy + min toxicity)

Question 30

How do you ensure a testing process is fair and valid?

Answer 30

volunteers should be blind to drugs and given half real + half placebo - doctors could also be blind to it (double blind) which prevents bias, then peer-reviewed

Question 31

What are monoclonal antibodies?

Answer 31

a single clone of cells which then produce antibodies that are then isolated, made in laboratory

Question 32

Why are B-lymphocytes not used for monoclonal antibodies?

Answer 32

they don’t divide quickly, so they’re combined with fast-diving tumour cells to make hybridoma

Question 33

Why are hybridoma preferred for usage in monoclonal antibodies?

Answer 33

produces a lot of antibodies, divides rapidly - when left in petri dish, it leaves an army of hybridoma which produce identical antibodies which are collected and purified

Question 34

What is the process of monoclonal antibodies?

Answer 34

animal is injected with antigen we want the antibody to bind to and then we do hybridoma thing > monoclonal antibodies bind to one specific thing - with right b-lymphocyte we can create antibodies that bind to anything we want

Question 35

What are pregnancy tests?

Answer 35

a test strip that is able to detect HCG hormones in a pregnant woman’s urine, cheap way of finding out pregnancy

Question 36

What is on the test strip of a pregnancy test to allow it to work?

Answer 36

Blue beads (located where you pee, free to move, covered in antibodies specific to HCG), fixed to the test strip antibodies (also specific to HCG)

Question 37

What happens on a pregnancy test if you are not pregnant?

Answer 37

urine will wash blue beads along the strip flowing over the antibodies - nothing will result as of this

Question 38

What happens on a pregnancy test if you are pregnant?

Answer 38

HCG in urine will bind to blue bead antibodies which will then flow over fixed antibodies and HCG will cause beads to bind to fixed antibodies resulting in a blue line (most have 2 - for functionality proof + pregnant proof)

Question 39

How can we tell a plant has a disease?

Answer 39

take basic observations and match to symptoms in a gardening manual (for example) or send to a plant pathologist

Question 40

What are some examples of physical plant defences?

Answer 40

waxy cuticle, cellulose cell walls, layer of dead cells (e.g. bark)

Question 41

What are some examples of chemical plant defences?

Answer 41

anti-microbial, poisons, drugs derived from plants

Question 42

What are some examples of mechanical plant defences?

Answer 42

thorns, hairs, leaves that curl of droop