Biology · Edexcel Paper 1
Health and Infectious Disease
What health means, the difference between communicable and non-communicable disease, the four types of pathogen and the infections they cause, how disease is spread and how the spread is reduced, and sexually transmitted infections, followed for separate Biology by stomach ulcers, Ebola and the life cycle of a virus. Matches Edexcel 5.1 to 5.8. Lessons 1 to 4 are for both Combined Science and separate Biology at Foundation and Higher. Lessons 5 and 6 are for separate Biology only.
Lessons
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1
Health and Types of Disease
Health is more than not being ill. This lesson looks at the World Health Organization's definition, at communicable and non-communicable diseases, and at why…
9 terms -
2
Pathogens and Common Infections
Four kinds of organism cause infectious disease. This lesson describes viruses, bacteria, fungi and protists, and five common infections: cholera…
10 terms -
3
How Diseases Spread and Are Prevented
Stopping a disease from spreading is better than treating it afterwards. This lesson looks at the four main routes of infection, in water, in the air, by…
10 terms -
4
Sexually Transmitted Infections
Some infections are passed on through sexual contact. This lesson explains how chlamydia and HIV are spread, what they do to the body, and how their spread can…
9 terms -
5
Stomach Ulcers and Ebola
One of these diseases was found to be caused by a bacterium only in the 1980s, and the other can kill about half of the people it infects. This lesson is for…
9 terms -
6
The Life Cycle of a Virus
Viruses are not cells, and cannot reproduce on their own. This lesson is for separate Biology only: Combined Science students do not need it. It explains how…
9 terms
Key terms in this chapter
All 56, gathered from every lesson.
- Health
- A state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity.
- Communicable disease
- A disease that can be passed from one person to another, caused by a pathogen.
- Non-communicable disease
- A disease that cannot be passed from one person to another, and is not caused by a pathogen.
- Pathogen
- A microorganism that causes disease.
- Susceptibility
- How likely a person is to get a disease.
- Immune system
- The body's defence against pathogens.
- Malnutrition
- A condition caused by a diet that does not provide the right nutrients in the right amounts.
- Correlation
- A relationship between two variables, where a change in one is linked to a change in the other.
- WHO
- The World Health Organization, the United Nations agency that works on global health.
- Pathogen
- A microorganism that causes disease.
- Virus
- A tiny particle made of genetic material in a protein coat, that can only reproduce inside host cells.
- Bacterium
- A single-celled prokaryote with no nucleus.
- Fungus
- An organism, such as a mushroom or yeast, that digests its food outside its body and absorbs it.
- Protist
- A mostly single-celled eukaryote.
- Toxin
- A poison made by a pathogen, which damages the host's tissues.
- Host
- The organism that a pathogen lives in or on.
- Dehydration
- A harmful loss of water from the body.
- AIDS
- The stage of HIV infection when the immune system has failed and serious infections develop.
- Lesion
- An area of damaged or diseased tissue.
- Transmission
- The spread of a pathogen from one host to another.
- Vector
- An organism that carries a pathogen from one host to another.
- Airborne
- Carried in the air, such as in droplets or as spores.
- Spore
- A tiny reproductive structure of a fungus, which can be carried by the wind.
- Sanitation
- Measures that keep people healthy by treating sewage and providing clean water.
- Isolation
- Keeping an infected person away from others, so that the disease cannot spread.
- Vaccination
- Giving a vaccine to protect against a disease.
- Insecticide
- A chemical that kills insects.
- Standing water
- Water that does not flow, where mosquitoes can breed.
- Mode of transmission
- The route by which a pathogen is passed on.
- Sexually transmitted infection (STI)
- An infection that is passed on through sexual contact.
- Chlamydia
- A common bacterial STI that is often symptomless and is treated with antibiotics.
- HIV
- The virus that attacks the immune system and can lead to AIDS.
- Antiretroviral drug
- A drug that reduces the amount of HIV in the body.
- Condom
- A barrier that stops body fluids passing between people during sex.
- Screening
- Testing people who may have no symptoms to find an infection early.
- Pelvic inflammatory disease
- Inflammation of the female reproductive organs, which can cause infertility.
- Needle exchange
- A scheme that gives clean needles to people who inject drugs, to prevent HIV spreading.
- Symptomless
- Having no symptoms.
- Helicobacter pylori
- A spiral-shaped bacterium that lives in the stomach and causes ulcers.
- Stomach ulcer
- An open sore in the lining of the stomach.
- Oral transmission
- Spread by swallowing a pathogen, for example in food, water or saliva.
- Ebola
- A viral disease that causes haemorrhagic fever.
- Haemorrhagic fever
- A fever with bleeding, caused by damage to blood vessels.
- Body fluids
- Liquids from the body, such as blood, vomit, faeces and sweat.
- Contact tracing
- Finding and watching the people who have been in contact with an infected person.
- Protective equipment
- Clothing and masks that protect health workers from infection.
- Inflammation
- Redness, swelling and pain caused by the body's response to damage or infection.
- Capsid
- The protein coat that surrounds the genetic material of a virus.
- Lytic pathway
- A virus life cycle in which new viruses are made at once and the host cell bursts.
- Lysogenic pathway
- A virus life cycle in which the viral DNA joins the host's chromosome and is copied with it.
- Lysis
- The bursting open of a cell, releasing its contents.
- Provirus
- Viral DNA that has been joined into the chromosome of a host cell.
- Host cell
- A cell that a virus infects and uses to reproduce.
- Replication
- Making copies, such as of genetic material.
- Receptor
- A molecule on the surface of a cell that a virus or other chemical can bind to.
- Dormant
- Inactive, but able to become active again.