BIOLOGY A LEVEL

What is Biology?

The common answer to this question is to say, ‘Biology is the study of life and living things’.  This is true.  But in the 21st century, there is so much more to biology than that. 
Biology is arguably the least understood, fastest moving and most contemporary science subject. In recent years biology has superseded Physics and Chemistry as the ‘fashionable’ science. Biological advances are increasing in number and sophistication almost by the month. It is rare to pick up a daily newspaper without finding a biologically related story. How often have you heard recently about climate change, global warming, MRSA superbugs, designer babies or cloning of embryos?

Ashbourne’s A level Biology Tutors

The department is lead by Ashbourne’s Director of Studies, John Wilson.  John is an Oxford graduate and has a PGCE from the University of Cambridge.  He has experience of teaching biology to pre-GCSE, GCSE and A-level in the state and independent sectors. Pauline Vickers and Helen Mason add a wealth of experience to the biology
department. Helen is a graduate of the University of Cambridge and Pauline is a graduate of Bristol and Newcastle Universities.

Examination Board

We have chosen to use the Edexcel A-level biology specification because we feel it is the best structured and most flexible of all the major A-level examination boards. The specification we follow was approved by the QCA for teaching the newly structured A levels from September 2008.

Units

The A-level biology specification is comprised of 6 units, two of which require students to complete a practical based coursework element.
Below is a summary of the units undertaken by A-level biology students at Ashbourne:

Unit 1 BIOL1: Biology and disease

1.1 Disease may be caused by infectious pathogens or may reflect the effects of lifestyle.

Pathogens
Lifestyle

1.2 The digestive system provides an interface with the environment. Digestion involves enzymic hydrolysis producing smaller molecules that can be absorbed and assimilated.

The digestive system.
Proteins
Enzyme action.
Enzyme properties
Carbohydrate digestion
1.3 Substances are exchanged between organisms and their environment by passive or active transport across exchange surfaces. The structure of plasma membranes enables control of the passage of substances across exchange surfaces.

Cells
Plasma membranes
Diffusion
Osmosis
Active transport
Absorption
Cholera

1.4 The lungs of a mammal also act as an interface with the environment. Lung function may be affected by pathogens and by factors relating to lifestyle.

Lung function
The biological basis of lung disease

1.5 The functioning of the heart plays a central role in the circulation of blood and relates to the level of activity of an individual. Heart disease may be linked to factors affecting lifestyle.

Heart structure and function
The biological basis of heart disease

1.6 Mammalian blood possesses a number of defensive functions.

Principles of immunology

Unit 2 BIOL2: The variety of living organisms

2.1 Living organisms vary and this variation is influenced by genetic and environmental factors.

Investigating variation
Causes of variation

2.2 DNA is an information-carrying molecule. Its sequence of bases determines the structure of proteins, including enzymes.

Structure of DNA
Genes and polypeptides
DNA and chromosomes

2.3 Similarities and differences in DNA result in genetic diversity.

Genetic diversity

2.4 The variety of life is extensive and this is reflected in similarities and differences in its biochemical basis and cellular organisation.

Haemoglobin
Carbohydrates
Cells

2.5 During the cell cycle, genetic information is copied and passed to genetically
identical daughter cells.

Replication of DNA
Mitosis
Cell cycle

2.6 In complex multicellular organisms, cells are organised into tissues, tissues into organs and organs into systems.

Cell differentiation

2.7 Factors such as size and metabolic rate affect the requirements of organisms and this gives rise to adaptations such as specialised exchange surfaces and mass transport systems.

Size and surface area.
Gas exchange
Mass transport
The blood system
The passage of water through a plant

2.8 Classification is a means of organising the variety of life based on relationships between organisms and is built round the concept of species.

Principles of taxonomy

2.9 Originally, classification systems were based on observable features but more recent approaches draw on a wider range of evidence to clarify relationships between organisms.

Genetic comparisons
Proteins
Behaviour

2.10 Adaptation and selection are major components of evolution and make a significant contribution to the diversity of living organisms.

Antibiotics
Genetic variation in bacteria

2.11 Biodiversity may be measured within a habitat.

Species diversity
Index of diversity

Unit 3 – Internal Assessment: Investigative and practical skills in AS Biology

Either BIO3T, Or BIO3X,

3.1 Investigating biological problems involves changing a specific factor, the independent variable, and measuring the changes in the dependent variable that result.

3.2 Implementing involves the ability to work methodically and safely, demonstrating competence in the required manipulative skills and efficiency in managing time. Raw data should be methodically collected and recorded during the course of the investigation.

3.3 Raw data may require processing. Processed data should be used to plot graphs that illustrate patterns and trends from which appropriate conclusions may be drawn.

3.4 Limitations are inherent in the material and apparatus used, and procedures adopted. These limitations should be identified and methods of overcoming them suggested.

Unit 4 BIOL4: Populations and environment

4.1 The dynamic equilibrium of populations is affected by a number of factors.
Populations and ecosystems

Investigating populations
Variation in population size
Human populations

4.2 ATP provides the immediate source of energy for biological processes.

ATP

4.3 In photosynthesis, energy is transferred to ATP in the light-dependent reaction and the ATP is utilised in the light-independent reaction.

Photosynthesis
Light-dependent reaction
Light-independent reaction
Limiting factors

4.4 In respiration, glycolysis takes place in the cytoplasm and the remaining steps in the mitochondria. ATP synthesis is associated with the electron transfer chain in the membranes of mitochondria.

Aerobic respiration
Anaerobic respiration

4.5 Energy is transferred through ecosystems and the efficiency of transfer can be measured.

Energy transfer
Energy and food
production

4.6 Chemical elements are recycled in ecosystems. Microorganisms play a key role in recycling these elements.

Nutrient cycles
Carbon
Nitrogen

4.7 Ecosystems are dynamic systems, usually moving from colonisation to climax communities in the process of succession.

Succession

4.8 Genetic variation within a species and geographic isolation leads to the accumulation of different genetic information in populations and the potential formation of new species.

Inheritance
The Hardy-Weinberg principle
Selection
Speciation

Unit 5 BIOL5: Control in cells and in organisms

5.1 Stimuli, both internal and external, are detected and lead to a response.

Survival and response
Control of heart rate
Receptors

5.2 Coordination may be chemical or electrical in nature.

Principles
Nerve impulses
Synaptic transmission

5.3 Skeletal muscles are stimulated to contract by nerves and act as effectors.

The sliding filament theory of muscle contraction
Muscles as effectors

5.4 Homeostasis is the maintenance of a constant internal environment.

Principles
Temperature control
Control of blood glucose concentration

5.5 Negative feedback helps maintain an optimal internal state in the context of a dynamic equilibrium. Positive feedback also occurs.

Principles
Control of mammalian oestrus

5.6 The sequence of bases in DNA determines the structure of proteins, including enzymes.

The genetic code
Polypeptide synthesis
Gene mutation

5.7 Gene expression is controlled by a number of features. Most of a cell’s DNA is not translated

Regulation of transcription and translation

5.8 Gene cloning technologies allow study and alteration of gene function in order to better understand organism function and to design new industrial and medical processes.

Gene cloning and transfer
Gene therapy
Medical diagnosis
Genetic fingerprinting

Unit 6 – Internal Assessment: Investigative and practical skills in A2 Biology

Either BIO6T Or BIO6X

6.1 Investigating biological problems involves changing a specific factor, the independent variable, and measuring the changes in the dependent variable that result.

6.2 Implementing involves the ability to work methodically and safely, demonstrating competence in the required manipulative skills and efficiency in managing time. Raw data should be methodically collected and recorded during the course of the investigation.

6.3 Raw data may require processing. Processed data should be used to plot graphs that illustrate patterns and trends from which appropriate conclusions may be drawn.

6.4 Limitations are inherent in the material and apparatus used, and procedures adopted. These limitations should be identified and methods of overcoming them suggested.

Possible University Degree Programmes Suited to A-level Biology

Common degree programmes related to A-level biology include: Medicine (and related disciplines), Dentistry,
Veterinary Science, Pharmacology,
Physiology,
Biomedical Science,
Biology,
Applied Biology, Biochemistry

However, throughout their A-level studies, A-level biology students learn and develop skills that allow them to communicate, analyse, criticise, argue and discuss.  They tend to be numerate and literate and are able to present data and information in a variety of different ways.  These skills are invaluable for students who go on to study ANY degree discipline and who are interested in ANY line of work. 

Ashbourne’s A-level biology students have gone on to read for a vast range of degrees including: Philosophy,
Psychology,
Business,
Chemical Engineering,
Mathematics and
Economics. The skills they developed whilst studying A-level biology will doubtless have been of assistance to them during their degree programmes.