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Ecosystems and material cycles

Pollution indicators - Higher

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Biology practicals

Investigating specimens using microscopes

Investigating the effect of pH on amylase activity

Investigating molecules in food using food tests

Investigating osmosis in potatoes

Investigating the effect of antimicrobials

Investigating limiting factors of photosynthesis

Investigating the rate of respiration

Using field-work techniques

Ecosystems and material cycles

Ecosystems, competition and environmental changes

Trophic levels and biomass transfer

Human impacts on biodiversity

Conservation and maintaining biodiversity

The carbon cycle

The water cycle

Obtaining potable water

The nitrogen cycle

Pollution indicators - Higher

Decomposition and biogas

Exchange and transport in animals

Specialised exchange surfaces

Factors affecting the rate of diffusion

Human circulatory system

Aerobic and anaerobic respiration

Animal coordination, control and homeostasis

The human endocrine system

Hormones: adrenaline and thyroxine - Higher

Hormones in human reproduction

Treating infertility - Higher

Homeostasis and blood glucose

Controlling body temperature

The urinary system

Plant structures and their functions

Photosynthesis and limiting factors

Factors limiting the rate of photosynthesis - Higher

Water and mineral transport in plants

Plant adaptations

Plant hormones

Health, disease and the development of medicines

The relationship between health and disease

Communicable disease

Sexually transmitted infections

How the body fights disease

Vaccination, immunisation and medicines

Aseptic techniques

Drug development and testing

Monoclonal antibodies and their uses - Higher

Non-communicable diseases

Calculating BMI and the waist-to-hip ratio

Cardiovascular disease and treatment

Plant defences and diseases

Natural selection and genetic modification

Evolution by natural selection

Fossils as evidence for evolution

Classifying living organisms

Selective breeding

Uses and evaluation of genetic engineering

The process of genetic engineering - Higher

Uses of genetic engineering

Genetics

Meiosis, sexual and asexual reproduction

Sexual and asexual reproduction

DNA: structure, genes and chromosomes

Protein synthesis - Higher

Inheritance and genetic diagrams

Inherited disorders

Blood groups, co-dominance and haemophilia

Types and sources of variation

The human genome project

Cells and control

The cell cycle and stages of mitosis

Cell differentiation, stem cells and ethics

The structure of the brain

The nervous system and the reflex arc

The eye: structure, reflexes and defects

Key concepts

Eukaryotic and prokaryotic cells

Specialised animal and plant cells

Types of microscopes and calculations

Enzymes

Calorimetry and energy calculations

Transport systems in cells

Practical skills

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

Science communication and ethics

Evaluating risks and hazards

Collecting data

Processing and presenting data

Units and equations

Structuring a scientific report and drawing conclusions

Uncertainties and evaluations

Explainer Video

Tutor: Holly

Summary

Pollution indicators

In a nutshell

Living organisms are all adapted to live in different conditions. Some organisms are well adapted to living in polluted conditions. Their presence or absence can give an indication of the pollution level. The impact of human activity on a habitat can be studied using these organisms. These organisms are known as indicator species.

Water pollution

Water can become polluted by fertilisers or sewage. This pollution can cause eutrophication which will decrease the concentration of oxygen in the water. The types of living organism that are found in the water will depend on the level of pollution.

Pollution level	Organisms present
Polluted water	Blood worms and sludgeworms are adapted to live in low oxygen environments. Therefore, these will be found in polluted water.
Clean water	Stonefly larvae, freshwater shrimps and mayflies will be found in clean water. They are very sensitive to oxygen concentrations so they would not survive in polluted water. Therefore, their presence indicates clean water.

Air pollution

The air can become polluted in a variety of different ways, like sulphur dioxide being released from power stations and car exhausts.

Lichen

Lichen is a symbiotic relationship between a fungus and algae or cyanobacteria. Lichen is sensitive to sulphur dioxide concentrations so the type of lichen that grows will indicate the level of pollution in the area.

Type of lichen present	Explanation
Bushy	Bushy lichen can only survive in unpolluted areas so these indicate very clean air.
Leafy	Leafy lichen can survive in environments with a small amount of pollution so these indicate clean air.
Crusty	Crusty lichen can survive in polluted environments so the presence of only these will indicate polluted air.

Blackspot fungus

Blackspot fungus grows on the leaves of rose plants. The fungus is damaged by sulphur dioxide so in areas of high air pollution, the fungus can not grow. This means that in polluted areas, the leaves of the roses will not have blackspot fungus.

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Unit 1

Photosynthesis and plant adaptations

Unit 2

Ecosystems and interdependence

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