A resource aimed at Advanced Level Biology students, this worksheet introduces the dual layout of the mammalian circulatory system and then provides a series of questions that would consolidate understanding following a dissection of a heart. The worksheet effectively provides a starter and plenary task to any lesson involving a heart dissection. Key words: Circulatory, heart, pulomonary, aorta, artery, vein, valves, cardiac, ventricles, atria

A resource aimed at Advanced Biology students, this worksheet provides a list of questions related to understanding the events of the cardiac cycle. The questions focus on the characteristic pressure change graph that shows AV valves and semi-lunar valves opening and closing as pressure of blood between artery, atria and ventricles changes. Students often struggle to articulate the difference in pressure as the cause of valves opening and closing; these questions will help to reinforce key concepts. Key words: artery, ventricle, atria, semi-lunar, atrio-ventricular, pressure

A single powerpoint slide that can be printed A3 size and used as a homework task for A-Level Biology students. Many students do not appreciate the link between their knowledge of biochemistry, photosynthesis and plant growth. This activity will make clear that every biological molecule present in a plant can trace itself to the glucose first produced in photosynthesis and subsequent modification into proteins, lipids and nucleic acids via the addition of further minerals.

A worksheet aimed at A-Level Biology students whereby they must decide which is the appropriate statistical test to use (out of Spearman Rank, 95% confidence limits and standard error and chi-squared). A useful exercise to do with a class once the principles of these statistical tests has been taught; can students confidently decide which is the appropriate test to use?

A quiz that tests students understanding on the first part of the nitrogen cycle, involving nitrogen fixation. There is a series of twenty one questions that require simple responses. This is ideal to use as a lesson starter activity as a check on whether students can remember the detail of what they have been taught and serves to reinforce vocabulary.

A quiz that asks students to give the correct word that matches each description. Useful as a recap of key vocabulary. The worksheet also contains an extension question based on quadrat sampling where students are asked to calculate population density of a plant species.

A worksheet of questions related to the nitrogen cycle which students are required to research. Each series of questions is divided into separate categories according to which part of the cycle they relate to: nitrogen fixation, nitrification, ammonification, denitrification, etc. A useful worksheet to issue at the start of a topic as background research for students to gain familiarity with the key ideas. Keywords: Nitrogen, cycle, ammonifiication, denitrification, nitrification, saprobiont, decay, fixation

An activity aimed at A-Level Biology students. This activity involves a series of statements that can be given to a class at the start of a lesson with the instruction that they draw the nitrogen cycle based on this information. Students should initially do this in pairs but can then be teamed up in larger groups to show, discuss and explain their own diagrammatic interpretations of the nitrogen cycle. Finally, the whole class can be brought together to discuss the best way of joining these statements together into an agreed nitrogen cycle. Key words: Nitrogen, cycle, ammonification, nitrification, denitrification, saprobiont, decay, symbiotic, rhizobium, azotobacter, decomposition, photosynthesis, respiration, combustion, fossilisation, assimilation, feeding, herbivore, carnivore, carbonate

An activity aimed at A-Level Biology students. This activity involves a series of statements that can be given to a class at the start of a lesson with the instruction that they draw the carbon cycle based on this information. Students should initially do this in pairs but can then be teamed up in larger groups to show, discuss and explain their own diagrammatic interpretations of the carbon cycle. Finally, the whole class can be brought together to discuss the best way of joining these statements together into an agreed Carbon Cycle. Key words: Carbon, cycle, decomposition, photosynthesis, respiration, combustion, fossilisation, assimilation, feeding, herbivore, carnivore, carbonate, ocean, diffusion

A worksheet aimed at A-Level Biology students that provides four questions to practice their knowledge of the technique of mark-release-recapture. The questions also test student's understanding of the limitations of this technique and causes of inaccuracies Key words: Mark, release, recapture, biology, limitations, assumptions, N1, N2, n, population, estimate

A worksheet aimed at A-Level Biology students that looks at various examples of restriction enzymes and whether they are suitable for cutting out a gene from a sequence of DNA. Students must look carefully at the restriction recognition sequence for each enzyme and decide whether it is suitable for removing the gene. This is based on whether the recognition sequence occurs in the middle of the gene or at the ends and whether the enzyme will leave blunt or sticky ends. Key words: Restriction, enzyme, blunt, sticky, gene, DNA, EcoR1, HindIII, BamH1

This worksheet is aimed at A-Level Biology students and covers the principles of restriction mapping of plasmids using restriction enzymes. This is often a difficult topic for students to understand, but this worksheet covers the basic principle, worked examples and also provides some questions for students to practice the principles. Key words: Restriction, enzyme, plasmid, mapping, kilobases, DNA, base pairs, restriction site, fragment, electrophoresis

A worksheet aimed at A-Level Biology students that requires students to read a passage of text, study diagrams and answer questions that require application of knowledge on the Carbon Cycle. The stimulus material is in the context of space science research and mapping of the Earth's oceans. Phytoplankton are a major carbon sink and their numbers are declining, possibly as a result of global warming. This worksheet considers the implications of this change. Keywords: Phytoplankton, Carbon cycle, space, satellite, envisat, sink. oceans, greenhouse, global warming

A summary worksheet for A-Level Biology comprising three exercises, including calculation of population growth, interpretation of survival curves and interpretation of population pyramids (showing increasing, stable and decreasing population). Key words: Population, pyramid, biology, survival, curves, graph, growth, increase, percentage

A worksheet that reviews the key points about succession in an ecosystem: what it is, how it happens, sequence of events, factors affecting and different types. The worksheet also has a question on diversity index in a mown and unmown lawn as an example of deflected succession. Key words: Succession, diversity, climax, community, grass, shrubs, pioneer, species, trees, index, primary, secondary, deflected

A worksheet that uses a respirometer as an example of a spearman rank exercise. Students are required to analyse the data provided to see whether there is any correlation between temperature and oxygen consumption. Key words: Spearman Rank, temperature, respirometer, oxygen, correlation, consumption, null hypothesis, probability

A quick test comprising four questions on mark-release-recapture, use of random sampling with quadrats and chi-squared statistical analysis. Useful at the end of a series of lessons on ecology as a quick review of key principles. The assessment includes answers to all the questions. Key words: chi-squared, mark-release-recapture, random sampling, quadrats, ecology, test, exam, answers, quiz

A worksheet that provides secondary data from an investigation into the population density/abundance of plant species in a field. The worksheet requires some calculations to estimate population density and total population size across the whole field. There is also consideration of the reasons why quadrats are always deployed randomly and why random sampling is required for any fieldwork investigation. Key words: quadrat, fieldwork, dandelions, daisies. estimate, population, density, abundance, calculations

A worksheet aimed at A-Level Biology students that compares and contrasts pyramids of number with pyramids of biomass. The worksheet requires students to perform simple calculations of total biomass and consideration of the pyramid shapes that result. Key words: biomass, number, pyramid, energy, loss, efficiency

A worksheet aimed at A-Level Biology students which sets out a series of research tasks for students to learn about the nitrogen cycle. A good resource to use at the start of this topic as homework or in class by dividing out each piece of key research among the class. Internet websites are listed which provide useful animations and information for students to use as they complete their research. Key words: nitrogen cycle, deamination, ammonification, denitrification, nitrification, nitrogen fixation, nitrogen, ammonia, nitrite, nitrate, ammonium ions, symbiotic