Biology Flashcards
Disease
When your body isn’t functioning as it should - microorganisms get into body and change how it works
Pathogens are _____ which enter your body and cause disease
Microbes
What microbe causes tuberculosis?
Bacteria (0.001mm)
What microbe causes H.I.V?
Virus (0.00005mm)
What microbe causes Athletes foot?
Fungus (0.001mm)
What microbe causes Malaria?
Parasite (plasmodium) - 0.003mm
What are the four main categories of disease?
- Infection (caused by pathogens) e.g flu or AIDS
- Deficiency disease (caused by lack of nutrients) e.g scurvy or anaemia
- Inherited disease (caused by faulty gene) e.g cystic fibrosis or haemophilia
- Body disorders (many causes!) e.g diabetes, cancer
Cancer is when a group of _____ are _______ uncontrollably
A group of cancerous cells is called a ____
1) cells
2) dividing
3) tumour
What are the two tumours?
- Beign : doesn’t spread to others, not usually dangerous
- Malignant : cancerous cells can break off and spread to other organs, causing tumours there to be more dangerous
What are bacteria?
Tiny living microbes
What cells in your body fight infections and how?
White blood cells:
1) produce antibodies which sticks to microbes making it easier for the cells to engulf them
2) the cells can eat bacteria whole
How does a vaccination work?
1) weakened microbes are injected into your body to make antibodies
2) your body recognises the microbe so will produce antibodies more quickly
Who invented small pox vaccine?
Edward Jenner
What conditions to bacteria and fungi like to grow in?
Warm and wet places
Who discovered penicillin?
Alexander Flemming
What is an antiobiotic?
A substance produced by a microbe which kills bacteria
Why is a person more likely to have another disease after suffering from one before?
1) One disease damages the immune system, easier for pathogens to cause disease
2) A disease damages the body’s natural barriers and defence, allowing pathogens to get into the body more easily
3) A disease stops an organ system from working effectively, making other diseases more likely to occur
What is a communicable disease?
A disease caused by pathogens (they are passed from an infected person to other people)
What is a non-communicable disease?
A disease which is NOT passed from one person to another (caused by genes or lifestyle)
Why can malnutrition cause disease?
It either give you too much or too little of particular nutrients
What is cardiovascular disease?
A disease affecting the heart (‘cardio’) and blood vessels (‘vascular’)
Two factors that increase the risk of cardiovascular disease are …
- obesity
- smoking
How do you measure the amount of body fat - assuming that the mass of other body tissues is in proportion to height?
BMI = mass / height (to power of 2)
What method is used to work out abdominal fat?
waist-to-hip ratio (waist:hip)
How does smoking cause disease?
- substances from tobacco smoke damage the artery lining
- fat builds up in the artery wall at the site of damage, making the artery narrower
- a blood clot may block the artery here, or break off and block an artery in another part of the body - causing a heart attack or stroke
How to treat cardiovascular disease?
Insert a small mesh tube (stent) at the narrowest part to hold it open. Blocked arteries in the heart can by bypassed by inserting other blood vessels so that the heart tissue is supplies with oxygen and nutrients again.
What pathogens are prokaryote?
Bacteria
What pathogens are eukaryote?
Protist, Fungus
Where is a virus’ DNA located?
Protein shell
Where is a bacteria’s DNA located?
Cell cytoplasm
Where is a protist’s DNA located?
Nucleus
Where is a fungus’ DNA located?
Nucleus
Is a Virus single-celled or multicellular?
Neither (non-cellular) - can only reproduce inside living cell
Is a bacteria single-celled or multicellular?
Single-celled
Is a protist single-celled or multicellular?
Both
Is a fungus single-celled or multicellular?
Mostly multi-cellular
What are the 5 human defences?
- tears
- stomach
- scabs
- skin
- lungs
How do tears defend the human body?
Contain antibacterial chemicals
How does the stomach defend the human body?
Produces acid that kills any microorganisms that enter our stomach
How do scabs defend the human body?
Scabs are found after blood clots when you cut yourself. It prevents pathogens from entering the wound.
How does skin defend the human body?
An organ that covers the entire surface of our body. It prevents bacteria and viruses from reaching the important tissues that can be infected.
How do the lungs defend the human body?
Lined with mucus that traps bacteria and cilia that sweeps mucus back into the gullet, where it is swallowed and destroyed by the stomach.
What happens during a non-specific immune response? (phagocytosis)
1) The body recognises a pathogen has entered the body
2) The phagocyte engulfs the pathogen
3) The pathogen is destroyed. This is called phagocytosis
What happens during a specific immune response?
1) The body recognises a pathogen has entered the body
2) Specific lymphocytes are activated
3) The lymphocytes divide and produce antibodies
4) The antibodies attach to the antigens and destroy the pathogen
There are two types of immunity, ______ and ______
- natural
- artificial
How does natural immunity work?
- Antibodies are passed from mother to child
- Antibodies are made when microbes infect the body
How does artificial immunity work?
Passive: serum of antibodies are injected directly into person to right infection
Active: vaccine with dead or modified microbes are injected causing antibodies to be produced ready for real infection
How does a vaccine help prevent disease when a child?
1) vaccine contains inactive forms / antigens of pathogens are given to the child
2) antigens on the pathogen cause and immune response (activate lymphocytes in the blood system that ‘match’ the antigen)
3) activated lymphocytes divide rapidly to produce more lymphocytes or release antibodies to the antigen
4) some lymphocytes become memory lymphocytes that stay in the blood after the immune response ends
5) exposure to the live pathogen triggers a secondary response
6) a secondary response produces larger amounts of antibodies more quickly than first exposure to the pathogen
7) the secondary response usually prevents illness, so the person is immune to the disease
Developing medicines:
many medicines are developed from _____ that ____ use to ____ themselves
- substances
- plants
- protect
Give 2 examples of medicines
1) Aspirin -> originally produced from salicylic acid (made by several plants such as willow trees)
2) Artemisinin -> originally extracted from the wormwood plant, kills the PLASMODIUM protists that cause malaria
Why do we need to develop new medicine?
- More diseases discovered so new medicines needed
- To develop even more effective medicines with less side effects
- To develop medicines that can be used to patients who may be allergic to available medicines e.g penicillin
What are the steps of developing a new medicine?
1) a disease is chosen and possible new medicines are made in lab
2) tested in the lab on cells, tissues and organs (pre-clinical tests)
3) tested on animals
4) tested on healthy human volunteers (stage 1 clinical trials)
5) tested on human volunteers with the disease (stage 2 clinical trials)
6) the medicine passes all the legal tests and is licensed. It can now be administered by doctors.
Why is medicine tested in a lab when being developed?
To learn how the medicine affects the pathogen, without risking people’s health
Why is medicine tested on healthy humans when being developed?
To identify side effects and check how effective medicines are on different people
Antibiotics can only be used to treat _____ infections because they _____ cell processes in the _____, but not the host _____
1) bacterial
2) inhibit
3) bacterium
4) organism
