Infection and Response - Fighting Diseases and Monoclonal Antibodies 87-98

Question 1

what features does the body have to to stop pathogens getting in
5 points

Answer 1

1) the skin acts as a barrier, it also secretes antimicrobial substances which kill pathogens
2) hairs and mucus in your nose trap particles that could contain pathogens
3) the trachea and bronchi secrete mucus to trap pathogens
4) the trachea and bronchi are lined with cilia, these hair-like structures, which waft the mucus up to the back of the throat where it can be swallowed
5) the stomach produces hydrochloric acid, this kills pathogens that make it that far from the mouth

Question 2

what are the ways white blood cells defend against pathogens inside the body
3 points

Answer 2

1) phagocytosis
2) producing antibodies
3) producing antitoxins

Question 3

what is phagocytosis

Answer 3

where white blood cells engulf foreign cells and digest them

Question 4

what do antibodies do

Answer 4

1) every invading pathogen has unique molecules called antigens on its surface
2) when some types of WBC come across a foreign antigen the will start to produce proteins called antibodies
3) these will lock onto the invading cells so that they can be found and destroyed by other WBC
4) the antibodies produced are specific to that type of antigen
5) antibodies are then produced rapidly and carried around the body to find similar pathogens
6) if a person is infected with the same pathogen again the WBC will rapidly produce the antibodies to kill it

Question 5

what do antitoxins do

Answer 5

these counteract the toxins produced by the invading bacteria

Question 6

what is a vaccination
3 points

Answer 6

1) inject small amounts of dead or inactive pathogens into the body
2) these carry antigens which cause your body to produce antibodies even though the pathogen is harmless
3) if live pathogens of the same type appear after, the WBC can rapidly mass-produce antibodies

Question 7

what are the advantages of vaccinations
2 points

Answer 7

1) they’ve helped control communicable diseases that used to be common in the UK - e.g. measles, rubella, mumps
2) epidemics can be prevented - so people who aren’t vaccinated are unlikely to catch the disease

Question 8

what are the disadvantages of vaccinations
2 points

Answer 8

1) they don’t always work
2) you can have a bad reaction to one e.g. swelling, fever, seizures - but bad reactions are rare

Question 9

what are painkillers and give an example of one
3 points

Answer 9

1) they are drugs that relieve pain
2) they don’t actually kill pathogens or tackle the cause of the disease
3) aspirin is a painkiller

Question 10

what are antibiotics
2 points

Answer 10

1) they kill the bacteria causing the problem without killing your own body cells
2) they don’t destroy viruses as they reproduce inside your body cells

Question 11

how can bacteria become resistant to antibiotics
4 points

Answer 11

1) the bacteria can mutate and become resistant to an antibiotic
2) if you have an infection and some of the bacteria is resistant only the non-resistant strains will be killed
3) the resistant bacteria will live and reproduce - the population will increase
4) the resistant strain could cause infection that can’t be treated with antibiotics

Question 12

how do you slow down the rate of development of resistant strains of bacteria
2 points

Answer 12

1) doctors shouldn’t over prescribe antibiotics
2) finish the whole course of antibiotics and don’t just stop once you feel better

Question 13

what are some examples of medicines we get from plants
2 points

Answer 13

1) aspirin - from willow tree
2) digitalis - from foxgloves

Question 14

give an example of a drug we get from microorganisms

Answer 14

penicillin

Question 15

what are the stages of drug testing
3 points

Answer 15

1) the drugs are tested on human cells and tissues in the lab
2) then test the drug on live animals
3) if the drug passes the test on animals, it’s tested in human volunteers in a clinical trial

Question 16

what are antibodies produced by

Answer 16

B-lymphocytes

Question 17

what are monoclonal antibodies produced from

Answer 17

lots of clones of a single WBC

Question 18

what is the process of making a monoclonal antibody
6 points

Answer 18

1) inject a mouse with a chosen antigen
2) this makes the mouse produce antibodies for this antigen
3) get fast-dividing tumour cells from the lab
4) fuse the antibody from the mouse to the tumour cell to make a hybridoma
5) hybridoma cells can be cloned to get lots of identical cells that all produce the same antibodies (monoclonal antibodies)
6) these antibodies can be collected and purified

Question 19

how are monoclonal antibodies useful
2 points

Answer 19

1) you can make them bind to anything
2) they only bind to one specific cell or chemical

Question 20

what is the hormone found only in the urine of pregnant women

Answer 20

HCG

Question 21

how do pregnancy tests work
2 points

Answer 21

1) the part of the test you wee on has some antibodies to the HCG hormone, with blue beads attached
2) the test strip has more antibodies to the hormone stuck to it

Question 22

what happens on a pregnancy test if you’re not pregnant
2 points

Answer 22

1) the urine still moves up the stick carrying the blue beads
2) but there’s nothing to stick the beads onto the test strip so it doesn’t go blue

Question 23

what happens on a pregnancy test if you’re pregnant
4 points

Answer 23

1) if you’re pregnant the hormone binds to the antibodies on the blue beads
2) the urine moves up the stick carrying the hormone and the beads
3) the beads and hormone bind to the antibodies on the strip
4) the beads get stuck on the strip turning it blue

Question 24

what are some of the uses of monoclonal antibodies
3 points

Answer 24

1) pregnancy tests
2) used to treat diseases
3) in labs and research to find specific substances

Question 25

how can you use monoclonal antibodies to treat cancer
6 points

Answer 25

1) cancer cells have antigens that aren’t found on any normal body cells called tumour markers
2) you can make monoclonal antibodies that bind to tumour markers
3) anti-cancer drug can be attached to these monoclonal antibodies
4) the antibodies are given to the patient through a drip
5) the antibodies only target the cancer cells as they only bind to tumour markers
6) the drug kills the cancer cells but not normal body cells

Question 26

how can monoclonal antibodies be used in research

Answer 26

1) can bind to hormones and other chemicals in blood to measure their levels
2) test blood samples in labs for certain pathogens
3) locate specific molecules on a cell or in a tissue

Question 27

how can monoclonal antibodies locate specific molecules on a cell or in a tissue
4 points

Answer 27

1) monoclonal antibodies are made that will bind to the specific molecules you’re looking for
2) the antibodies are then bound to fluorescent dye
3) if the molecules are present the monoclonal antibodies will attach to them
4) they can be detected using the dye

Question 28

what is a disadvantage to monoclonal antibodies
3 points

Answer 28

1) they cause more side affects than was expected
2) e.g. vomiting, fever and low blood pressure
3) so they aren’t as widely used as treatments as was hoped

Question 29

what mineral ions do plants need and why
2 points

Answer 29

1) nitrates - make proteins for growth
2) magnesium ions - make chlorophyll which is needed for photosynthesis

Question 30

what do a lack of mineral ions cause
2 points

Answer 30

1) lack of nitrates causes stunted growth
2) lack of magnesium ions causes chlorosis and have yellow leaves - meaning it can’t photosynthesise

Question 31

how can plants get diseases
2 points

Answer 31

1) by viral, bacterial and fungal pathogens
2) infested and damaged by insects like aphids

Question 32

what are some signs that a plant has a disease
6 points

Answer 32

1) stunted growth
2) spots on the leaves
3) patches of decay (rot)
4) abnormal growth e.g. lumps
5) malformed stems or leaves
6) discolouration

Question 33

how can you identify different plant diseases
3 points

Answer 33

1) looking up the signs in a gardening manual or website
2) taking infected plant to a lab where scientists can identify it
3) using test kits that identify pathogen using monoclonal antibodies

Question 34

what are the physical defenses on a plant
3 points

Answer 34

1) most have a waxy cuticle on leaves and stems which provides a barrier for pathogens
2) plant cells have a cell wall made from cellulose which acts as a barrier to pathogens that make it past the waxy cuticle
3) they have layers of dead cells around their stems that stop pathogens entering e.g. bark

Question 35

what are the plants chemical barriers
2 points

Answer 35

1) some can produce antibacterial chemicals which kill bacteria e.g. mint plant and witch hazel
2) others produce poisons which deter herbivores e.g. tobacco plants, foxgloves and deadly nightshade

Question 36

what are the plants mechanical defenses
3 points

Answer 36

1) some have thorns and hairs which stop animals from touching or eating it
2) some leaves droop or curl when something touches it
3) some mimic other organisms e.g. passion flower has bright yellow spots that look like butterfly eggs so butterflies wont lay their eggs there