Infection & response (seneca) Flashcards
Infections are caused whenever …
a foreign pathogen invades an organism (animal or plant).
There are four main types of pathogen:
- Viruses
- Bacteria
- Fungi
- Protists
Viruses are …
tiny, non-living (do not contain cells) particles that can reproduce rapidly within the body.
Viruses invade 1. and use them to make 2.
- host cells
- new virus particles.
Once the new viruses are made, they cause the cells to 1.
The cell damage makes us 2.
- burst.
- feel ill
Bacteria are …
small living cells that either damage cells directly or by producing toxins (poisons).
Bacteria can reproduce rapidly in the appropriate conditions:
warm, moist areas with a good supply of oxygen.
The toxins released by bacteria can …
damage cells and tissues, making us feel ill.
Some fungi are …
single-celled organisms that have a body made up of hyphae (thread-like structures).
The hyphae are able to …
grow and penetrate tissues, such as human skin or the surface of plants.
The hyphae produce …
spores that can spread to other plants and animals.
Protists are …
single-celled eukaryotic organisms (they have a nucleus).
Many protists are parasites, meaning that they …
live on or inside other organisms
Protists are often transferred to the host organism by…
a vector, such as an insect or mosquito.
Protists make us feel ill by …
damaging our tissues.
Some pathogens contaminate water supplies. Organisms drinking this contaminated water can be …
infected by pathogens.
Some pathogens contaminate water supplies. Organisms drinking this contaminated water can be infected by pathogens.
————- is a disease spread in this way.
Cholera
Some pathogens are released into the air inside droplets when an organism coughs or sneezes. These droplets can then be …
inhaled (breathed in) by other organisms.
Some pathogens are released into the air inside droplets when an organism coughs or sneezes. These droplets can then be inhaled (breathed in) by other organisms.
—————— are spread in this way.
The flu and common colds
Some pathogens live on the surface of other organisms, such as the skin. If infected skin touches a surface, …
some of the pathogens can transfer from the infected skin to the surface.
The pathogen then spreads to other people who also touch that surface. ————- is spread in this way.
Athlete’s foot
Vaccination can make people immune to …
(resistant to) infection.
The more individuals that are vaccinated, the less likely…
the disease is to spread.
By being hygienic, we can ——–pathogens or …
- destroy
- wash them away so that they are not spread.
————————————————————– are all hygienic measures to prevent the spread of infection.
Using antibacterial products to clean surfaces, washing our hands and sneezing into a handkerchief
By ———————–, we prevent contact with other organisms. This stops the infection from spreading.
isolating infected individuals
Some protist diseases are carried by …
vectors.
A vector is …
an organism that carries pathogens without being infected.
Some protist diseases are carried by vectors.
A vector is an organism that carries pathogens without being infected.
For example, we can protect against mosquitos carrying malaria using …
mosquito nets.
When a ——– invades an organism (animal or plant), it can cause an infection.
pathogen
ways of preventing infection:
- vaccination
- decrease vectors
- being hygienic
- isolation of infected individuals
To survive and replicate, viruses…
invade host cells (animals or plant cells)
The virus particle inserts …
its own DNA into the host cell’s DNA, which is then copied and used to make more viruses.
Once the new virus particles have been ———- (made), they cause the cell to burst.
synthesised
Symptoms of measles include …
a fever and red skin rash.
Measles is a —— that can be fatal if complications arise.
virus
Measles is a virus that can be …
fatal if complications arise.
Measles is a virus that can be fatal if complications arise.
For this reason, most young children are …
vaccinated against measles.
The measles virus is spread by …
breathing in (inhaling) droplets from sneezes and coughs.
Tobacco mosaic virus (TMV) is …
a pathogen that affects plants, such as tomatoes
When a plant has Tabasco mosaic virus, There is unique ‘mosaic’ pattern of the discolouration of the plant that …
stunts the growth of the affected plant, because photosynthesis cannot take place.
HIV is spread by …
sexual contact or the exchange of body fluids (e.g blood from sharing needles).
Initially, HIV causes a 1. However, unless antiretroviral drugs are used successfully, the HIV virus enters…
- flu-like illness
- the lymph nodes and attacks the body’s own immune cells.
AIDS is caused by 1. It is the name given to the 2.
- HIV
- life-threatening infections that can happen when a person’s immune system has been badly damaged by HIV.
How do HIV and AIDS differ?
- AIDS (Acquired Immune Deficiency Syndrome) is caused by HIV (Human immunodeficiency virus).
- It is the name given to the life-threatening infections that can occur when a person’s immune system has been badly damaged by HIV.
The virus particle inserts its own DNA into the ————-, which is then copied and used to make more viruses.
host cell’s DNA
If food has not been cooked properly or has been prepared in unhygienic conditions, then we may ingest (eat) …
Salmonella bacteria that cause food poisoning.
Salmonella bacteria release toxins (poisons), causing …
fever, stomach pain, vomiting and diarrhoea.
Gonorrhoea is a …
sexually transmitted disease.
Gonorrhoea symptoms include …
pain when urinating and a thick yellow or green discharge from the vagina or penis.
Barrier methods for gonorrhoea of contraception, such as 1. , can be used to 2.
- condoms
- stop the bacteria spreading from person to person.
Rose black spot can be spread in …
water or in the air (wind).
Rose black spot causes …
purple or black spots on the leaves of rose plants.
Eventually, Rose black spot causes the 1. This makes it 2.
- leaves discolour and fall off
- harder for plants to photosynthesise and plant growth slows.
When a plant has rose black spot, ————————————————– can treat affected plants.
Removing and destroying discoloured leaves and using fungicides
How do fungi spread and infect plants and animals?
- Fungi are unicellular or multicellular organisms that each have bodies made up of hyphae (thread-like structures).
- The hyphae are able to grow and penetrate tissues, such as human skin or the surface of plants.
- The hyphae produce spores, which can spread to other plants and animals
Malaria is spread by…
the female anopheles mosquito (a vector).
If a mosquito is carrying malaria, then it ————————- when it bites them.
transfers the infection into a person’s bloodstream
Malaria leads to —————-, which can cause death.
recurring and severe fevers
Fungi are ——— or ———- organisms that have bodies made up of hyphae
(thread-like structures).
unicellular
multicellular
Fungi are unicellular or multicellular organisms that have bodies made up of
…
hyphae (thread-like structures).
Mucus is produced in the 1. and traps …
- respiratory system
- the particles and bacteria entering our airways.
Glands in the stomach wall produce 1. , which destroys 2.
- hydrochloric acid
- any pathogens that enter the stomach.
Skin is a …
waterproof barrier that pathogens cannot pass through.
Good bacteria live …
permanently on our skin, covering the surface and preventing pathogens from growing on our skin.
Tears contain …
enzymes that destroy any pathogens that make contact with our eye.
If a pathogen passes the non-specific defences, the ———- is activated.
immune system
The immune system is made up of different —————, which have different functions.
white blood cells
what is Phagocytosis?
A process where a white blood cell finds the pathogen and engulfs it by changing shape.
The white blood cell ingests and digests the pathogen, destroying it.
Some bacteria produce toxins that can …
damage cells and tissues.
Some bacteria produce toxins that can damage cells and tissues.
The immune system responds to this by producing 1. , which 2.
- antitoxins
- neutralise the toxins released by the bacteria and prevent them from causing harm.
White blood cells recognise foreign antigens (proteins) on the surface of pathogens and produce…
protein molecules called antibodies.
Antibodies are specific to …
particular pathogens.
give examples of non-specific defences.
- tears
- skin
- mucus
- stomach acid
What kind of acid does the stomach produce?
Hydrochloric acid
Antigens are …
proteins found on the surface of cells.
White blood cells can recognise …
foreign antigens on the surface of pathogens and produce protein molecules called antibodies.
Antibodies have a complementary shape to the antigen and lock onto …
the pathogen, effectively ‘tagging’ them.
Antibodies have a complementary shape to the antigen and lock onto the pathogen, effectively ‘tagging’ them.
This causes the microorganisms to …
cluster, allowing other white blood cells to come and ingest (eat) them.
———— are small living cells that either damage cells directly or by producing toxins (poisons).
Bacteria
White blood cells are components of the:
Immune system
What are the main functions of the white blood cells in our immune system?
- Produce antibodies
- Phagocytosis
- Produce antitoxins
The cells lining the nose and throat have tiny hair-like structures called 1. on their surface. The cilia …
- cilia
- sweep the mucus upwards to the mouth.
Mucus is produced in the 1. and 2.
- respiratory system
- traps the particles and bacteria entering our airways
The human body is designed to prevent ——— from entering and causing harm.
pathogens
Antigens are proteins found on the surface of cells.
White blood cells can recognise …
foreign antigens on the surface of pathogens and produce protein molecules called antibodies.
Antibodies have a complementary shape to the antigen and lock onto the pathogen, effectively ‘———-’ them.
tagging
What name is given to the proteins found on the surface of cells that antibodies bind to?
Antigens
A vaccination injects a …
dead or inactive form of a pathogen into the blood
After killing the pathogen, some of these white blood cells remain in the blood as memory cells. If the same pathogen invades the body again, the memory cells are able to:
- Produce antibodies faster.
- Produce more antibodies, meaning that the antibody concentration remains in the blood for longer.
Vaccinating a large proportion of the community to protect everyone in the community is known as …
herd immunity.
Vaccinating the majority of people makes it hard for the pathogen to …
spread
What is the name given to the cells produced during vaccination that remain in the body?
Memory cells
What is a antibody?
Protein molecules produced by the white blood cells when recognising pathogens.
What is a pathogen?
A microorganism that causes a disease.
What is a Antigen?
Proteins found on the surface of some pathogens, with specific shapes that act like signals to allow cell recognition.
Some bacteria produce toxins that can damage cells and tissues.
The immune system responds to this by producing antitoxins, which …
neutralise the toxins released by the bacteria and prevent them from causing harm.
Phagocytes Are white blood cells which,
Engulf pathogens
What’s the difference between antitoxins and antibodies?
- Antibodies bind to specific antigens on the surface of pathogen cells.
- ## Antitoxins neutralise toxins produced by pathogens, preventing them from causing harm.
What are specific defenses to pathogens?
- antitoxins
- antibodies
White blood cells recognise foreign 1. on the surface of pathogens and produce protein molecules called 2.
- antigens
- antibodies
Antibodies have a —————- to the antigen on the surface of the pathogen and lock onto them, effectively ‘tagging’ them.
complementary shape
Specific antibiotics are prescribed by medical doctors for …
specific diseases
The use of antibiotics has greatly reduced the number of deaths from …
infectious bacterial diseases.
Antibiotics do not destroy viruses because …
viruses stay inside host cells and are not living cells.
Antibiotics are designed to cure infections caused by which type of organism?
Bacteria
Some antibiotics work by destroying the …
cell wall of the bacteria so that they can’t replicate.
MRSA is often called a “———-” because it is resistant to many antibiotics.
superbug
MRSA is often called a “superbug” because …
it is resistant to many antibiotics.
To help prevent strains of resistant bacteria from developing:
- Doctors should only prescribe antibiotics if they are needed and not for minor infections or viral infections.
- Patients should complete their course of antibiotics to ensure all bacteria are killed.
Within a population of bacteria, some will have random mutations (random change in DNA).
The mutated bacteria are …
resistant to antibiotics and so they are able to survive, whilst the non-resistant bacteria die.
Within a population of bacteria, some will have …
random mutations (random change in DNA).
The resistant bacteria can reproduce rapidly because …
their competition (the non-resistant bacteria) has been destroyed by the antibiotic.
When the resistant bacteria reproduce, they produce …
genetically-identical copies. These copies will all be resistant to the antibiotics.
Penicillin is a …
Antibiotics
Antibiotic resistance comes about partly because of…
Evolution and mutations
The heart drug Digitalis originates from …
foxgloves (a plant).
The heart drug Digitalis originates from foxgloves (a plant). It was first used …
200 years ago by William Withering.
The painkiller Aspirin originates from …
willow trees
———— discovered the antibiotic Penicillin, which is made from the Penicillium mould.
Alexander Fleming
Alexander Fleming discovered the antibiotic Penicillin, which is made from the …
Penicillium mold.
Nowadays, most drugs are synthesised (made) by …
chemists in the pharmaceutical industry.
Nowadays, most drugs are synthesised (made) by chemists in the pharmaceutical industry.
But the ingredients of these drugs may be chemicals extracted (taken) from …
plants
In the past, most drugs were extracted (taken from) from …
plants and microorganisms.
Scientists are always trialling new antibiotics for when …
new strains of resistant bacteria appear.
Painkillers are used to relieve the pain caused by an infection.
They do not …
cure diseases or kill pathogens, but they do relieve the symptoms.
——— is an example of a painkiller.
Aspirin
Viruses are found inside cells. This means it’s hard to …
destroy them without damaging the body’s cells and tissues.
Antiviral drugs are used to treat …
viral infections
What is the name given to drugs that kill viruses?
Antivirals
New medical drugs have to be …
tested and trialled before being used to check that they are safe and effective.
This testing can take many years and the drugs are tested on three main criteria:
- Efficacy
- Dose
- safety
Scientists carry out early stage testing on …
human cells and tissues grown in the laboratory.
Scientists also carry out early stage testing on …
live animals.
Testing on animals is useful for working out how …
toxic (harmful) a drug is to cells.
Clinical trials test drugs on ——————— to check that they are safe.
healthy volunteers and patients
If a drug is found to be safe at low doses, there are more clinical trials to work out the …
optimum (best) dose for the drug.
Double-blind trials make sure that a test is …
perfectly fair
Double-blind trials make sure that a test is perfectly fair.
If either the patient or doctor knew what they were taking, it could …
skew the outcomes of the trial.
In clinical trials, some patients are given a placebo (—————————-).
an alternative that does not contain any of the drug
In double-blind trials ————— groups receive treatment.
2 or more
Clinical trials of drug testing are done on healthy volunteers and patients to check that these new drugs are safe, usually using ——- doses of the drug.
low
In clinical trails, all the conditions are kept …
identical across the two groups so that only the drug has an impact on a patient’s health.
What is the vector for malaria?
Female anopheles mosquito
Fungi are unicellular or multicellular organisms that each have bodies made up of …
hyphae
The hyphae produce ——— that can spread to other plants and animals.
spores
White blood cells recognise that the antigens are foreign and produce ————- against them.
antibodies
The resistant bacteria can reproduce rapidly because …
their competition (the non-resistant bacteria) has been destroyed by the antibiotic.
Doctors should only prescribe antibiotics if they are needed and not for …
minor infections or infections from viruses, protists or fungi.
Patients should complete their course of antibiotics to make sure …
all the bacteria are killed.
What’s the first stage of drug testing?
Pre-clinical trials
If a drug passes the pre-clinical trials stage, what’s the next stage of testing called?
Clinical trials
Monoclonal antibodies are specific to …
one binding site on one protein antigen (on the surface of cells).
Monoclonal antibodies are specific to one binding site (area) on one protein antigen (on the surface of cells).
This means that …
monoclonal antibodies target specific chemicals or cells in the body.
Antibodies only fit to one …
antigen
A mouse is injected with the chosen antigen (obtained from a pathogen). The mouse’s immune system responds by producing …
lymphocytes (white blood cells) that produce the particular antibodies against that antigen.
A mouse is injected with the chosen antigen (obtained from a pathogen).
The mouse’s immune system responds by producing lymphocytes (white blood cells) that produce the particular antibodies against that antigen.
The lymphocytes are
extracted from the mouse and fused (combined) with myeloma cells (tumour cells) to form hybridoma cells.
A mouse is injected with the chosen antigen (obtained from a pathogen).
The mouse’s immune system responds by producing lymphocytes (white blood cells) that produce the particular antibodies against that antigen.
The lymphocytes are extracted from the mouse and fused (combined) with myeloma cells (tumour cells) to form hybridoma cells.
The myeloma (tumour) cells will …
grow rapidly and lots of identical cells are produced.
A mouse is injected with the chosen antigen (obtained from a pathogen).
The mouse’s immune system responds by producing lymphocytes (white blood cells) that produce the particular antibodies against that antigen.
The lymphocytes are extracted from the mouse and fused (combined) with myeloma cells (tumour cells) to form hybridoma cells.
The myeloma (tumour) cells grow rapidly and lots of identical cells are produced. All of the …
hybridoma cells produce the same antibody.
A mouse is injected with the chosen antigen (obtained from a pathogen).
The mouse’s immune system responds by producing lymphocytes (white blood cells) that produce the particular antibodies against that antigen.
The lymphocytes are extracted from the mouse and fused (combined) with myeloma cells (tumour cells) to form hybridoma cells.
The myeloma (tumour) cells grow rapidly and lots of identical cells are produced. All of the hybridoma cells produce the same antibody.
These monoclonal antibodies are
collected, purified and can then be used to target specific cells and chemicals.
The first step in producing monoclonal antibodies is to inject a mouse with the chosen ——- obtained from a pathogen.
antigen
Monoclonal antibodies are produced from ——- of cells. They are all identical and are complementary to one type of antigen.
clones
Monoclonal antibodies can be produced to …
bind (attach) to target cells in the body, e.g. cancer cells.
We can attach anti-cancer drugs to the …
monoclonal antibodies.
Monoclonal antibodies can be used in different ways. However, they may cause side effects such as —————- when used to treat patients
fevers, low blood pressure and vomiting
Monoclonal antibodies can be used in different ways. However, they may cause side effects such as fevers, low blood pressure and vomiting when used to treat patients. Because of these side effects, monoclonal antibodies are …
used less commonly than people first expected.
We can attach anti-cancer drugs to the monoclonal antibodies. When they bind to the cancer cells, they can …
deliver the drugs directly to the tumours.
Monoclonal antibodies can be produced to bind (attach) to target cells in the body, e.g. cancer cells. This is an effective cancer treatment because …
the antibodies cannot bind to or damage any normal human body cells (because normal cells will not have the complementary antigens).
Pregnant women produce a hormone called …
HCG
Pregnant women produce a hormone called HCG.
Monoclonal antibodies can be used in pregnancy tests to …
bind (attach) to the HCG hormone’s antigens.
Pregnant women produce a hormone called HCG.
Monoclonal antibodies can be used in pregnancy tests to bind (attach) to the HCG hormone’s antigens.
If the urine contains HCG, the antibodies …
bind and this shows that the person is pregnant.
Pregnant women produce a hormone called HCG.
Monoclonal antibodies can be used in pregnancy tests to bind (attach) to the HCG hormone’s antigens. If the urine does not contain HCG, then the …
antibodies will not bind to the HCG, showing a negative result.
Since monoclonal antibodies are specific to one antigen, they can be …
designed to identify specific chemicals in the blood.
Monoclonal antibodies identify …
particular molecules in a tissue or cell by binding to them with a fluorescent dye. Areas in the body with lots of these molecules can be highlighted using the dye.
Monoclonal antibodies can identify the levels of …
hormones in the blood.
Monoclonal antibodies can be used to test …
blood samples for pathogens, such as HIV.
Identify the uses of monoclonal antibodies:
- pregnancy tests
- treating diseases
- Identifying chemicals in blood
The first step in producing monoclonal antibodies is to inject a mouse with the chosen —— obtained from a pathogen.
antigen
Monoclonal antibodies are proteins and hence need to be ————- during storage and transport to prevent denaturation.
refrigerated
What is the name of the specific cell type that produces monoclonal antibodies?
Hybridoma cells
Plants need many mineral ions (minerals) for healthy growth. They extract most of these mineral ions from the soil. If the soil quality is poor, plants can suffer from ion deficiency conditions (disorders), such as(2):
- Magnesium deficiency
- Nitrate deficiency
—————- is required for the production of chlorophyll.
Magnesium
Magnesium is required for the production of chlorophyll.
This causes …
chlorosis
When magnesium is absent, plant leaves are …
yellow
Magnesium is required for the production of chlorophyll.
if magnesium is not present This causes chlorosis:
The plant cannot photosynthesise well. This means that it cannot produce the glucose needed for healthy growth.
————- are needed for the production and synthesis (creation) of proteins in plants.
Nitrates
Without proteins, plants cannot grow. This means that a nitrate deficiency causes …
stunted growth
Nitrate deficiencies cause stunted growth. This is because this ion is needed to produce:
proteins
Greenflies and black flies (both called aphids) feed on —————- in the phloem. This diverts sugars away from plants.
the sap (a liquid in plants that stores sugars, salts and amino acids)
Greenflies and black flies (both called aphids) feed on the sap (a liquid in plants that stores sugars, salts and amino acids) in the phloem. This …
diverts sugars away from plants.
Plants can suffer from fungal diseases, such as …
rose black spot.
Plants have lots of defences against infections and harm from other organisms. They include: ————— to stop animals eating the plants.
Thorns or hairs
Plants have lots of defences against infections and harm from other organisms. They include: Leaves that close up rapidly when touched decrease 1. They may also 2.
- the surface area available to herbivores
- dislodge smaller herbivores already on the plant.
Plants have lots of defences against infections and harm from other organisms. They include: Some plants use ———— to trick animals.
mimicry
Plants have lots of defences against infections and harm from other organisms. They include: ————— are produced by some plants, such as mint, garlic and witch hazel. They work like antibiotics to stop populations of bacteria from growing.
Antibacterial chemicals
Some plants use mimicry (copying) to trick animals.
An example is a …
pattern on leaves that resembles the presence of insect eggs. Insects avoid laying their eggs on them in order to avoid competition.
Plants have lots of defences against infections and harm from other organisms. They include: Poisons are produced by many plants, including …
foxglove and deadly nightshade, to deter herbivores.
Plants have lots of defences against infections and harm from other organisms. They include: Bark is made of …
dead cells that acts as a barrier of protection for the stem against pathogens and pests (like aphids).
Plants have lots of defences against infections and harm from other organisms. They include: ———— is a barrier on the surface of leaves and stems to stop pathogens invading leaf tissue.
Waxy cuticle
Plants have lots of defences against infections and harm from other organisms. They include: ————-, are a physical barrier to stop pathogens entering cells.
Cell walls, which are made of cellulose
Plants can have chemical defences. For instance, antibacterial chemicals work like antibiotics to prevent the growth of ——— , whereas poisons are produced to deter herbivores.
bacteria
What type of pathogen causes rose black spot?
Fungal
What is stored in cell sap in plants?
- amino acids
- salts
- sugars
Greenflies and black flies (both called ———-) feed on the sap (a liquid in plants that stores sugars, salts and amino acids) in the phloem. This takes sugars away from plants.
aphids
The following are all signs of plant disease:
- Malformed stems or leaves
- Areas of decay (rot)
- Stunted growth
- Spots on leaves
- Growths
- Discolouration
- Presence of pests
There are three methods you can use to identify a plant’s disease. These are:
- Testing kit
- Gardening manual
- Laboratory
Laboratory method can be used to identify a plant’s disease. This includes…
taking an infected plant to a laboratory to identify the pathogen.
Gardening manual can be used to identify a plant’s disease.
This includes…
a gardening manual or website.
Testing kits can be used to identify a plant’s disease.
This includes…
Using testing kits that contain monoclonal antibodies.
What do kits for testing plant disease contain?
Monoclonal antibodies
Monoclonal antibodies are specific to one binding site on one protein …
antigen
A mouse is injected with the chosen antigen (obtained from a pathogen).
The mouse’s immune system responds by producing lymphocytes (white blood cells) that produce the particular antibodies against that antigen.
The lymphocytes are extracted from the mouse and fused (combined) with myeloma cells (tumour cells) to form …
hybridoma cells
A mouse is injected with the chosen antigen (obtained from a pathogen).
The mouse’s immune system responds by producing lymphocytes (white blood cells) that produce the particular antibodies against that antigen.
The lymphocytes are extracted from the mouse and fused (combined) with myeloma cells (tumour cells) to form hybridoma cells.
The myeloma (tumour) cells grow rapidly and lots of ———- cells are produced.
identical
Where is sap found in a plant?
Phloem
If a plant has a magnesium deficiency, this will result in:
- yellow leaves
- lack of glucose
- chlorosis
