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Global challenges

Cancer and its risk factors

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Investigating specimens using microscopes

Investigating the effect of antimicrobials

Investigating osmosis in potatoes

Investigating the effect of pH on amylase activity

Investigating molecules in food using food tests

Investigating limiting factors of photosynthesis

Investigating human reaction times

Investigating seed growth under different conditions

Using field-work techniques

Investigating the effect of temperature on decay

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Ecosystems, competition and environmental changes

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Food chains and predator-prey graphs

The water cycle

The carbon cycle

Decomposition and biogas

Human impacts on biodiversity

Global warming and its consequences

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Trophic levels and biomass transfer

Food security and biotechnology

Inheritance, variation and evolution

DNA: structure, genes and chromosomes

Protein synthesis - Higher

Proteins and mutations

Meiosis, sexual and asexual reproduction

Sexual and asexual reproduction

Inheritance and genetic diagrams

Inherited disorders

Types and sources of variation

Evolution by natural selection

Evolution: Darwin, Lamarck and Wallace

Antibiotic resistance: causes and prevention

Selective breeding

Uses and evaluation of genetic engineering

The process of genetic engineering - Higher

Cloning in plants and animals

Fossils as evidence for evolution

The theory of speciation

Classifying living organisms

Homeostasis and response

Homeostasis and blood glucose

The nervous system and the reflex arc

The structure of the brain

The eye: structure, reflexes and defects

Controlling body temperature

The human endocrine system

Hormones: adrenaline and thyroxine - Higher

The urinary system

Hormones in human reproduction

Treating infertility - Higher

Plant hormones

Bioenergetics

Photosynthesis and limiting factors

How plants use glucose from photosynthesis

Factors limiting the rate of photosynthesis - Higher

Ideal conditions for photosynthesis - Higher

Aerobic and anaerobic respiration

Metabolism

Responses to exercise

Infection and response

Communicable disease

How the body fights disease

Vaccination, immunisation and medicines

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Monoclonal antibodies and their uses - Higher

Plant defences and diseases

Organisation

Cell organisation

Enzymes

The enzymes of the digestive system

The respiratory system and breathing rate

Human circulatory system

Cardiovascular disease and treatment

The relationship between health and disease

Non-communicable diseases

Cancer and its risk factors

Plant cell organisation

Water and mineral transport in plants

Cell biology

Eukaryotic and prokaryotic cells

Types of microscopes and calculations

Specialised animal and plant cells

The cell cycle and stages of mitosis

Binary fission in bacteria

Cell differentiation, stem cells and ethics

Transport systems in cells

Specialised exchange surfaces

Exchange surfaces in leaves and fish

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Measuring techniques

Safety and ethics

Designing experiments

Methods of heating substances

Working with electronics

Random sampling and sampling methods

Comparing results using percentage change

Working scientifically

The scientific method

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Collecting data

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Units and equations

Structuring a scientific report and drawing conclusions

Uncertainties and evaluations

Explainer Video

Tutor: Priya

Summary

Cancer and its risk factors

In a nutshell

Cancer is a disease caused by uncontrolled cell growth and division. There are certain risk factors that can increase the risk of developing some cancers.

Cancer

Cancer is a disease in which changes in some of the body's cells can result in uncontrolled growth and division. This leads to a mass of abnormal cells, also known as a tumour. There are two types of tumours: begin and malignant.

Benign tumours	Malignant tumours
Stay in one location	Spread to other parts of the body by breaking off and travelling in the bloodstream.
Do not invade other body parts	Can invade healthy tissues and form secondary tumours.
Not dangerous or cancerous	Dangerous and can be fatal. These are cancers.

Risk factors

Over the years, research has identified many factors that increase the risk for certain cancers. These include both genetic and lifestyle factors.

Lifestyle risk factors

Smoking	Cigarette smoke is linked to many cancers, including cancers of the lungs, mouth and throat.
Obesity	Being obese can put people at risk of over twelve different types of cancer.
Viral infection	Getting infected by certain viruses can increase the chance of some cancers. Example HPV virus
UV exposure	Exposure to UV radiation (which is produced by the sun) has been linked to developing skin cancer.

Genetic risk factors

Parents pass on their genes to their offspring. Occasionally, an individual may inherit faulty genes. These genes increase the risk of developing cancer.

Example

Inheriting a mutation in the $BRCA1$ gene can increase a person's risk of developing breast cancer.

Improvements in cancer treatment

Nowadays, people have a greater chance of surviving cancer. This is due to an improvement in treatments, the ability of doctors to diagnose cancer earlier, increased screening for cancer, and a greater awareness of the risk factors for cancer amongst the general population.

Learn with Basics

Length:

Unit 1

How the body fights disease

Unit 2

The relationship between health and disease

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Unit 3