INFECTION AND RESPONSE Flashcards
Explain why MRSA is causing problems in many hospitals.
MRSA is causing a problem because it is becoming resistant to the antibiotics being used to treat it therefore hospitals are less able to combat it
Explain, as fully as you can, how white blood cells protect us from disease.
some ingest/digest bacteria some produce antibodies; which destroy bacteria/viruses; some produce antitoxins; which counteract poisons released by bacteria
Some diseases can be tackled by using antibiotics and vaccination.
Explain fully why antibiotics cannot be used to cure viral diseases.
viruses live inside cells
viruses inaccessible to antibiotic
A recent study found that babies in 90 % of hospitals are infected with the MRSA
bacterium.
Explain how the MRSA bacterium has developed resistance to antibiotics.
It has mutated and duplicated to form identical resistant bacteria therefore meaning the bacteria is no longer recognised by the antibiotics
A person can be immunised against a disease by injecting them with an inactive form of a pathogen. Explain how this makes the person immune to the disease.
(stimulate) antibody production
by white blood cells
rapidly produce antibody on re-infection
In an immunisation programme such as that for MMR (Measles, Mumps and Rubella),
suggest why it is essential for a large proportion of the child population to be vaccinated in
order to protect the few individuals who are unable to be vaccinated.
Since a large population of children have been vaccinated it will be harder for the disease to be spread to those who haven’t got the vaccination
(HERD IMMUNITY)
What is the MMR vaccine used for
measles mumps and rubella
Explain what testing must be done before this new drug can be used to treat people.
pre-clinical trials of the new drug on cells and tissues
to test toxicity, dosage and efficacy
clinical trials / test on healthy volunteers patients at very low doses
so that you can monitor for safety / side effects and only then do trials to find the optimum dosage and test for efficacy
double blind trial / use of placebo
which does not contain the new drug
random allocation of the drug to patients in groups
so no one knows who has placebo / the new drug
Describe two ways to control the spread of malaria.
stop mosquitoes breeding
use mosquito nets
Name the process that the pondweed uses to produce oxygen
Photosynthesis
TMV can cause plants to produce less chlorophyll. This causes leaf discoloration. Explain why plants with TMV have stunted growth.
less photosynthesis because of lack of chlorophyll
therefore less glucose made
less energy released for growth
because glucose is needed for respiration
Suggest how scientists can use this plant to produce many plants with the TMV-resistant gene.
take stem cells from the meristem of the plant
Two symptoms of infection by
Salmonella
are vomiting and diarrhoea.
What causes these symptoms
toxins / poisons (secreted by /
from / in bacteria
Give two ways a person with a mild infection of Salmonella can help prevent the spread of the bacteria to other people.
wash hands before preparing food
isolate yourself
A person with AIDS may take longer than a healthy person to recover from a
Salmonella
infection
their immune system is damaged
so the white blood cells cannot kill bacteria
A student made the following hypothesis about the heart rate of smokers and non -smokers during exercise. “During exercise, the heart rate of smokers increases more than the heart rate of non -smokers.” Design an investigation that would allow you to test this hypothesis
two groups of people - non -smokers and smokers • have at least five people in each group or large groups • get each person to do (named) exercise • controlled variables: - same number of people in each group or large groups - same gender - same level of activity / exercise - same age - no health issues / illnesses - same type of exercise - same time for exercise • record heart rate for each person before and after exercise • calculate increase in heart rate for each person after exercise • compare results for each group
What condition may be treated using an
artificial pacemaker?
an irregular heart beat
Plants infected with aphids may show symptoms of magnesium deficiency. Magnesium deficiency symptoms include: • yellow leaves • stunted growth. Explain how a deficiency of magnesium could cause these symptoms.
yellow leaves due to lack of chlorophyll (therefore) less / no light absorbed (by chlorophyll) (therefore) lower rate of / no photosynthesis (therefore) plant makes less / no sugar / glucose (therefore) plant converts less / no sugar / glucose into protein (for growth, so growth is stunted)
Describe how the scientist would use the protein to produce the PVY
monoclonal antibody
.
inject the protein / it into a mouse combine lymphocytes with tumour / cancer cells to make hybridoma (cells) find a hybridoma which makes a monoclonal antibody specific to PVY (the scientist) clones (the hybridoma) to produce many cells (to make the an tibody)
In a person with CF, cells lining the lungs and digestive system
create too much
mucus.
The mucus can:
block the duct leading from the pancreas to the small intestine
block the tubes leading to the alveoli in the lungs.
Explain why children with CF grow more slowly than children without
CF
fewer (digestive) enzymes enter small intestine
(so) enzymes break down / digest less food
(therefore) less absorption of nutrients
(so) less glucose can enter the blood(stream)
(so) less (glucose) available for respiration
(less absorption of nutrients so) fewer amino acids can enter the blood(stream)
(so) less protein is made (for growth
less oxygen enters blood(stream) / reaches cells / organs / tissues
(ignore body / lungs)
•
(so) less (oxygen) available for (aerobic) respiration
•
(so) less energy released / available (for growth
Describe how scientists may use stem cells to create healthy lungs that are
not
rejected by the CF patient.
take stem cells from patient (bone marrow / skin) remove / change / fix the faulty / CF gene create embryo using these stem cells remove stem cells (from embryo) and stimulate / allow them to divide / differentiate into lung (cells
Give
one
other reason why some people disagree with the use of stem cells to create
new organs for transplants
REligious reasons
what are pathogens
A pathogen is a microorganism that causes a disease.
types of transmission
Direct contact
This can be sexual contact during intercourse or non-sexual contact, like shaking hands.
Water
Dirty water can transmit many diseases, such as the cholera bacterium.
Air
When a person who is infected by the common cold sneezes, they can spray thousands of tiny droplets containing virus particles to infect others.
Unhygienic food preparation
Undercooked or reheated food can cause bacterial diseases like Escherichia coli which is a cause of food poisoning.
Vector
Any organism that can spread a disease is called a vector
TMV
It infects the chloroplasts of plant leaves and changes their colour from green to yellow or white in a mosaic pattern. It can also make leaves crinkle or curl up.
This reduces the plant’s ability to photosynthesise and grow properly, which reduces the crop yield for farmers.
HIV/AIDS
This infection is transmitted by body fluids, often during unprotected sex, but also through cuts and injecting drugs using shared needles. Immediately after infection, people often suffer mild flu-like symptoms. These pass and for a period of time infected people might not know they are infected.
AIDS- Attacks the persons immune system
how to stop aids
no cure for aids
doctors give patients anti viral drugs to slow the development of AIDS
measles
virus
It is transmitted through the air in tiny droplets after an infected person sneezes
It causes a fever and skin rash.
vaccination
gonnorhea
bacterial disease
green or yellow discharge when urinating
use conttraceptiom
treated by antibiotics
salmonella
bacterial disease uncooked food, unprepared food lead to vomiting and diahrohea prepare food properly in hygenic kitchens all uk foods are vaccinated against it
protists
Protists are a group of microorganisms that have features that belong to animals, plants and fungi.
symptons of malaria
fever sweats or chills
how to stop malaria
stop mosquito breeding
mosquito nets
types of fungal diseases
athletes foot
rose black spot
rose black spot
Rose black spot is caused by a fungus which infects roses. It infects leaves and causes black or purple spots on the leaves. The rest of the leaves often turn yellow and can drop off the plant. This reduces that plant’s ability to photosynthesise and reduces growth. It can be transmitted in air or water, as well as through direct contact by gardeners. It is treatable using fungicides and by removing and destroying infected leaves.
Non-specific human defence systems against disease
skin nose trachea bronchi stomach
how does skin protect
The skin covers almost all parts of your body to prevent infection from pathogens. If it is cut or grazed it immediately begins to heal itself, often by forming a scab, which prevents infection as the skin acts as a physical barrier.
how is the nose
The nose has internal hairs, which act as a physical barrier to infection. Cells in the nose produce mucus. This traps pathogens before they can enter the lungs.
stomach
stomach acid
immune system protection
Phagocytes surround any pathogens in the blood and engulf them. The phagocytes membrane surrounds the pathogen and enzymes found inside the cell break down the pathogen in order to destroy it.
They recognise proteins on the surface of pathogens called antigens. Lymphocytes detect that these are foreign not naturally occurring within your body and produce antibodies.
what do wbc produce
antitoxins
antibodies
malignant
these tumours are cancerous and can break apart, move around the body
benign
benign - these tumours are less serious because they are not cancerous, and do not spread
cancer treatment
chemotherapy, by using chemicals to kill cancerous cells
radiotherapy, by using x-rays to kill cancerous cells
