B5 Communicable diseases - Biology paper1 Flashcards
What is polio?
A serious viral infection that used to be common worldwide.
Is Polio still common nowadays?
No, nowadays polio is rare and can be prevented through vaccination.
What is a life threatening risk of catching polio?
Temporary or permanent paralysis.
When was routine vaccination for polio first introduced in the UK?
In the 1950’s
Is there a cure for polio?
No
When was the last natural outbreak of polio?
1949 in the USA
How many different viruses are known to cause symptoms of the common cold?
Over 200
What is a communicable disease?
A disease caused by a pathogen that can be passed on to other living organisms.
What is a non communicable disease?
A disease that can’t be spread to other living organisms.
What’s a similarity between communicable and non communicable diseases?
They’re both diseases that can have potentially fatal outcomes.
What are examples of communicable diseases?
Flu/colds,
HPV
Measles
HIV/AIDS
What are examples of non communicable diseases?
Obesity
Diabetes
Heart disease
Cancer
What lifestyle factors can affect your health?
Lack of exercise alcohol consumption smoking eating/drinking unhealthily where you live in the world
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What are 2 risk factors of developing obesity?
Lack of exercise and diet.
If someone lives in a congested environment with loads of pollution then what disease may they have a higher risk factor of developing?
Lung cancer, chronic obstructive pulmonary disease (COPD)
What is a risk factor of type 2 diabetes?
A poor diet
What is a risk factor of cardiovascular disease?
Stress
What is a risk factor of liver disease?
Alcohol
What is a risk factor of breast cancer?
Genetic mutations
What is a risk factor of asthma?
Air pollution
What can high fat and sugary diets cause?
- Obesity, which could then lead to heart problems
- Depression
- Type 2 diabetes
- High blood pressure
- Higher risk of strokes, because of the lack of oxygen to the brain
What can high fat and sugary diets cause?
- Obesity, which could then lead to heart problems
- Depression
- Type 2 diabetes
- High blood pressure
- Higher risk of strokes, because of the lack of oxygen to the brain
What are the causes of stress?
Pressure, divorce , studies etc
What does stress do to your body?
Stress causes hormones to be released, which causes blood vessels to constrict and blood pressure to rise.
What can stress lead to?
Depression, which can also increase the risk of obesity, diabetes and heart-related illnesses.
What is a pathogen?
A microbe that causes disease.
What is another name for a communicable disease?
An infectious disease
What is an example of an interacting disease?
Cancer can cause stress, which could bring about raised blood pressure.
What are the 4 types of pathogens?
Bacteria, protists, fungi and virus
What are examples of viruses?
Measles, flu, Influenza, rabies
What are examples of bacterial diseases?
Salmonella, typhoid , leprosy, cholera, tuberculosis, plague, gonorhoea
Can a virus be treated with antibiotics?
No
What are the features of bacteria?
- Cell membrane
- Ribosomes
- Prokaryotic
- Cell walls
- Have a flagella(whip-like tail) for movement
- Plasmids of DNA
- Chromosomal DNA
What is a carcinogen?
A chemical or other agent which causes cancer.
Is a bacteria cell prokaryotic or eukaryotic?
prokaryotic
How does bacteria cause disease?
Bacteria can divide quickly and spread inside living organisms. The bacteria produce toxins that damage body tissue and make you feel ill.
How do viruses cause disease?
Viruses can’t divide on their own and need to take over the cells of living organisms, in order to rapidly reproduce. This directly damages the cells.
Do bacteria directly damage cells?
No they damage cells through the toxins they produce.
What types of diseases does fungi cause?
Athlete’s foot , rose black spot
What are protists?
Single celled eukaryotic organisms, such as malaria.
How do diseases spread?
- Untreated/ polluted water
- Coughing and sneezing
- Sexually transmitted diseases
- through contact with others
What is a difference between bacteria and viruses?
Bacteria divide on their own but viruses take over living cells.
Bacteria doesn’t directly damage body tissue, but viruses do
What did Ignaz Semmelweis notice?
That his colleagues cut themselves during dissection and got ill. He then proposed handwashing as a way to prevent disease.
What did Joseph Lister do?
Inspired by the work of Pasteur, Lister suggested the filtration and heating of chemicals to destroy infections. He also tried to make antiseptics to treat people with infections.
What did Lister do in 1865?
He applied a bandage soaked in carbolic acid on a boy with a fractured leg. Over 4 days, o infection developed.
What is another name for carbolic acid?
Phenol
What are vectors?
Small disease carrying organisms that can transmit pathogens to other living organisms.
What are examples of vectors?
Mosquitoes, ticks and houseflies.
What do vaccines do?
They prevent the spread of disease by preparing our immune systems to fight off a pathogen before we actually come in contact with it.
How do vaccines start an immune response in our bodies?
Because they contain a weakened pathogen, this will start an immune response in our bodies and our immune system will create the antibodies needed to fight the pathogen. Then, when we come in contact with active pathogens, our bodies should immediately respond and protect us.
What are the symptoms of measles?
- Red rash
- runny nose and sneezing
- high temperature
- light sensitivity
Why can’t antibiotics be used to treat measles?
Because measles is a viral infection and you can’t kill a virus, only prevent its spread.
How does measles spread?
Through the air(coughs and sneezes).
What are symptoms of HIV?
Runny nose, high temperature, swollen glands and joint pain
How is HIV transmitted to others?
Through the direct contact of body fluids.
What part of the body does HIV attack?
The immune system
What happens when HIV attacks the immune system?
It makes you unable to fight off any ilnesses.
How is the measles controlled?
Through vaccination and isolation
How is HIV controlled?
Through antiretrovial drugs
How do antiretrovial drugs help control HIV?
They prevent replication of the virus
How is tobacco mosaic virus controlled?
Through the removal of the diseased plant and by washing hands after touching the infected plant.
What is the growth rate of bacteria affected by?
Temperature
Available nutrients
Oxygen levels
pH
What is tobacco mosaic virus?
A widespread plant pathogen that causes discoloured leaves and destroys cells.
What are 3 symptoms of tobacco mosaic virus?
Mosaic pattern, small leaves, yellowing of leaves
What structure do viruses have?
A simple structure
What coat do viruses have?
A protein coat
What is inside viruses?
Genetic material(DNA & RNA)
T/F Viruses have a variety of shapes
T
How could a delay in diagnosis lead to the spread of a virus?
People may not know what virus they have and so they end up passing it on.
What are the 2 main steps in calculating the mean of bacteria in a population?
1) Calculate how many times the bacteria will divide in the selected time’
2)Calculate the number of bacteria in the population, using the equation:
bacteria at the end of growth period = bacteria at beginning * 2^number of divisions
What is a disinfectant?
A chemical used to kill bacteria in the environment around us
What is an antissepetic?
A disinfectant that is safe to use on human skin.
What’s an antibiotic?
A chemical that can be used inside our bodies and that can kill bacteria and prevent them growing.
What happens in the mitochondria?
Respiration
What do ribosomes do?
Build proteins
What type of cells are bacterial cells?
Prokaryotic
What is a flagella?
A whip-like tail used for movement.
Where is the DNA stored in bacterial cells?
In the cytoplasm as Plasmids.
What are plasmids?
Rings of DNA
What do bacteria share to help them evolve, and why?
Bacteria share plasmids to help them evolve. This allows for the bacteria to develop resistance against anti-biotics, without waiting for changes in their DNA.
What is salmonella?
Food poisoning.
Can salmonella be spread between people?
Yes, eg if you use the same utensils as someone infected with salmonella
How can salmonella be transmitted?
- By eating contaminated foods
- Having contact with infected animals or their environment.
- Between people
What are the symptoms of salmonella?
- Diarrhea
- abdominal cramps
- fever
- nausea
- vomiting
- headache
Name some methods to reduce the transmission of salmonella…
~Cooking/pasteurizing food
~Avoid eating raw or undercooked egg/meat
~Wash hands before eating
How is gonorrhea transmitted?
Through vaginal, anal or oral sex
What are the general symptoms of gonorrhea?
Discharge, itching, soreness, bleeding, painful bowel movements
How could you reduce the transmission of gonorhea?
- By being in a long term relationship with someone who’s been tested negative
- By using latex condoms
What pathogen causes salmonella?
Bacteria
What pathogen causes gonorhea?
Bacteria
How can gonorrhea and salmonella be treated?
Using antibiotics
Give an example of 2 STD’s.
- Gonorrhea
- HIV
Why are antibiotics used to treat gonorrhea infections?
Because gonorrhea is a bacterial disease and so antibiotics can kill the bacteria
What are the recent problems faced by doctors in the treatment of gonorrhea ?
Many antibiotic resistant strains of gonorrhea have evolved an so it’s increasingly difficult to treat.
What is argobacterium tumefaciens?
Agrobacterium tumefaciens is a bacterium species that causes crown gall disease in plants. This is like cancer and a tumour develops where the bacterium has infected the plant. Often the tumours appear in the stems or roots of the plants.
What are antibiotics?
Medications that destroy or slow down the growth of bacteria.
Can antibiotics be used to treat viral infections?
No, because you can’t kill a virus , only prevent its spread.
What can be done to prevent bacterial resistance?
Avoiding unnecessary use of antibiotics.
Name some methods for preventing the spread of bacterial diseases:
- Antibiotics- when necessary
- Barrier contraceptives
- Getting vaccinated
- Preventing cross-contamination
- Cooking raw foods properly
What are protists?
Single-celled organisms that cause disease.
Why are protists eukaryotic?
Because they have a proper nucleus.
What is the vector that carries malaria?
Mosquitoes
What are vectors?
Organisms that spread disease but don’t cause it themselves.
What is malaria’s protist called?
Plasmodium Falciparum
What are the symptoms of malaria?
- Muscle pains
- Headaches
- Diarrhoea
- Sweats and chills
- Cough
Recurring episodes of fever
Is malaria a communicable or non communicable disiease and why?
Communicable, because it’s spread by a pathogen.
What is the malaria cycle?
- The first infected mosquito injects plasmodium - the protist- into the bloodstream of a person
- The liver cells get infected.
- Red blood cells get infected and produce toxins that make a person feel ill.
- Second mosquito bites infected person and then spreads the protist to a person.
How can you reduce the transmission of malaria?
- Taking drugs to kill the protist in the blood
- Using mosquito lights
- Spraying pools of water with oil to prevent the larvae from breathing
- Spraying pools of water with insecticides to kill the mosquitoes
- Draining stagnant pools of water.
- Using mosquito nets to avoid bites (spraying the nets with insecticides can also kill any mosquitoes that land on the nets)
How are fungal disieses spread?
Through human contact, infected soil, or contaminated surfaces.
Are fungal diseases life threatening?
Not necessarily, unless the spores reach vital organs
Where are fungal diseases most common?
In plants
How can spores of a fungus be spread?
By the wind
Fungal cells have a nucleus and so they are….
Eukaryotic
What is Athlete’s foot?
A rash caused by a fungus that is usually found between people’s toes.
What are the symptoms of Athlete’s Foot?
- Dry, red, scaly and flaky skin
- White, soggy and cracked skin
- Itchy, sore, small blisters
Name some ways you can get Athlete’s Foot..
- Wearing shoes that cause you to feel hot and sweaty
- Walking around barefoot
- Sharing towels, socks and shoes
- By having a weakened immune system
Where are people most likely to get athlete’s foot from?
It is often found in communal areas like swimming pool changing rooms or gyms
Name some methods of preventing Athlete’s foot….
- Wearing breathable socks, such as cotton
- Wearing new socks everyday
- Changing shoes every couple of days
- Moisturising toes, using talcum powder
How can athlete’s foot be treated?
Using antifungal medication
What is rose black spot caused by?
Rose black spot is caused by a fungus which infects roses
What are the symptoms of rose black spot?
- Yellowing leaves
- Black/purple spots
- Leaves falling off
- Less flowers
How is rose black spot spread?
Through air, water and through direct contact with other gardeners
How can rose black spot be treated?
- Using fungicides
- Removing and destroying infected leaves
Why does rose black spot affect plants?
Because the damage of the leaves stunts photosynthesis and the plants ability to produce glucose and proteins.
Name some different ways that pathogens can enter our body
Nose, mouth, blood, skin and eyes
How do our tears prevent pathogens from entering our eyes?
Tears have a high salt content that desicates (dries up) microorganisms. Tears also help to wash out our eyes.
How do our eyelashes prevent pathogens from entering our eyes?
The eyelashes act as a barrier which protects the eye when it’s open. This prevents micro-organisms from entering.
How does the nose prevent micro-organisms from entering the body?
There are hairs in our nose that trap particles and prevents infections. This is also done by producing mucus and When the nose is blown, the mucus, and any pathogens that are trapped within it, is removed.
How does the stomach help to prevent infection?
The hydrochloric acid in our stomach kills micro-organisms.
How does the blood prevent infection form pathogens?
When the skin is cut, scabs form to prevent pathogens from entering the blood.
What makes up the body’s first line of defence against pathogens?
The skin, the nose, the trachea & bronchi, and the stomach.
What does the skin secrete to prevent pathogens from entering our body?
Anti-microbial liquids that kill pathogens
What does the trachea and bronchi do to defend against pathogens?
-The trachea runs from the larynx (voice box) to the bronchi. The cells that line the trachea have hairs called cilia, which are much smaller than those in the nose. These are called ciliated cells. The ciliated cells waft their hairs and move mucus and pathogens upwards towards the throat where they are swallowed into your stomach.
Other cells called goblet cells create the mucus in order to trap pathogens. The production of mucus in your airways is a physical barrier.-
Are viruses alive?
No, Viruses are not considered alive because they do not complete all of the seven life processes, ie movement, respiration, sensitivity, nutrition, excretion, reproduction and growth.
What happens if pathogens pass through the non-specific first line of defence?
The pathogens will cause an infection
What is the body’s second line of defence and what does it consist of?
The immune system, which consists of our phagocytes and lymphocytes (white blood cells).
Why are phagocytes non-specific?
Because they engulf and digest all bacteria that they encounter.
What do phagocytes do?
They produce enzymes, which help them engulf and destroy bacteria.
What do lymphocytes do?
- They recognise proteins on the surface of pathogens called antigens and then produce antibodies to make it easier for the phagocytes to destroy the bacteria.
- Lymphocytes can also produce anti-toxins to help neutralise the toxins that pathogens may produce.
Are lymphocytes specific or non-specific and why?
Specific because both the antibodies and antitoxins are highly specific to the antigen on the pathogen
What is binary fission?
A form of cell division used by prokaryotic organisms to reproduce. A cell replicates all its genetic material and gets bigger during binary fission.
In binary fission, is the replicated cell identical to the original cell?
No the replicated cell isn’t identical to the original cell.
What does it mean to culture bacteria?
To grown in very large numbers so that scientists can see all the bacteria (the colony) as a whole.
How do we prepare to culture bacteria?
- Bacteria need to be provided with everything they need , so they’re given a culture medium.
- The culture medium contains many nutrients : carbohydrates, as an energy source; a nitrogen source, to make proteins and various minerals and sometimes other chemicals.
- Most micro-organisms will also need warmth and oxygen to grow.
Name the different steps involved in preparing an uncontaminated culture:
1) The petri dish and agar gel must be sterelised.
2) The innoculating loop should also be sterelised by being heated with a bunsen burner.
3) Open the petri dish
4) Innoculate the agar gel using the innnoculating loop by dipping it in the chosen bacteria and then in the gel (in zig zag shapes).
5) Replace the lid of the petri dish immediately
6) Fix the lid with tape, but don’t seal all the way around.
7) Label the petri dish upside down to stop condensation falling on the agar surface.
8) Incubate the dishes for a few days and observe the bacterial growth.
What is innoculating ?
The process of introducing micro-organisms into a place where they’ll grow
What does it mean to incubate something?
To keep at a favourable temperature to promote cell division and growth.
What is sterelisation?
The process of making something free from micro-organisms.
What is a nutrient broth?
A liquid solution in which bacteria can be grown
What is agar gel used to do?
To make a plate on which colonies of bacteria can grow.
Name the ways of growing bacteria?
- Using a nutrient broth
- Using agar plates
In schools why are bacteria only incubated at 25 degrees?
Because if we incubated any higher, we could risk growing very dangerous pathogens
What temperature to hospitals incubate pathogens?
At 37 degrees
Why do hospitals incubate pathogens at 37 degrees?
So that bacteria can grow as fast as possible and be identified sooner.
What does the xylem do?
Transports water up a plant
What does the phloem do?
Transports food, and dissolved sugars produced by photosynthesis up a plant
Name some causes of plant disease…
- Viruses
- Bacteria
- Fungus
- Nematode worms
- Insects
- Mineral ion defficiencies
What is an example of an insect that causes plant disease?
An aphid
What are aphids and what do they do?
Insects that have long, sharp mouthpieces that pierce the surface of the stem and into the phloem so that they can feed on the sugar-filled sap.
What are the symptoms of a plant destroyed by aphids?
- Damaged stem and leaves
- Presence of green insects covering stem
How do aphids cause damage to a plant?
- Penetrate phloem, which damages/weakens the plant
- Can also act as vectors and transfer viruses, bacteria and fungi
How can aphids be destroyed?
By using biological pest control to feed on the aphids, or by using chemical pesticides.
What can be used as biological pest control to kill aphids?
Ladybirds
What do nematode worms/insect larvae do?
They feed on the plant roots and damage them so that they can’t absorb water and mineral ions efficiently.
What are the symptoms of nematode worms?
Damaged plant roots
How do nematode worms cause damage to a plant?
They prevent the plant from getting the water and mineral ions they need so the plant fails to grow
What do nitrates supply plants with?
Nitrogen
What are the symptoms of a plant having a nitrate defficiency?
- Pale green/yellowing leaves
- Stunted growth
How does a nitrate defficiency cause damage to a plant?
Reduces the plants ability to photosyntheise, as the amount of chlorophyll in leaves reduces
What can be added to plants to increase nitrate levels?
Chemical or natural fertlisers, such as manure
What do plants use magnesium ions to make?
Chlorophyll
What are the symptoms of a magnesium ion defficiency?
Leaves turning yellow (chlorosis)
How does a magnesium defficiency cause damage to a plant?
As the magnesium ions are’t present to make chlorophyll, the leaves become yellow and growth slows because the plant can’t photosynthesise fully.
What does HIV stand for?
human immunodeficiency virus.
What does AIDS stand for?
acquired immune deficiency syndrome
What is the most common STI in Britain?
Chlamydia
What bacteria causes Chlamydia?
chlamydia trachomatis
What can happen if chlamydia is left untreated?
If left untreated, it can cause infertility in adults and could also cause conjunctivitis in babies during the process of birth if the mother is infected.
How can the transmission of chlamydia be prevented?
by the use of condoms and it can be treated with antibiotics such as tetracycline or erythromycin.
