practical that includes that activity. The list below shows the apparatus and techniques that are covered by one activity only and alternatives to the required practical. Note: there is a possibility that the student could be asked questions about the required activity in written papers that would not be fully understood by carrying out the alternative. This should be considered when deciding whether to repeat the required activity. Biology If a student misses this won’t have covered Other practicals within an …they required practical activity… this apparatus and Biology course involving technique. this skill 2. Preparation of stained d. use of light microscope at Examination of permanent squashes of cells from plant high power and low power, mounts of any tissue, related to root tips; set-up and use of an including use of a graticule specification content, in optical microscope to identify students use both high- and the stages of mitosis in these low-power objectives of an stained squashes and optical microscope and use a calculation of a mitotic index. stage micrometer and eyepiece graticule to measure the actual size of cells. 7. Use of chromatography to g. separate biological Separation of any aqueous investigate the pigments compounds thin mixture related to specification isolated from leaves of different layer/paper chromatography or content, eg, sugars or amino plants, eg leaves from shade- electrophoresis acids, by paper or thin layer and shade-intolerant chromatography. plants or leaves of different Extraction of 'chlorophyll' from a colours. plant or alga and separation of its constituent pigments by paper or thin layer chromatography. Separation of DNA fragments by electrophoresis. 12. Investigation into the effect k. use sampling techniques in Use of random quadrats to of a named environmental fieldwork investigate the pattern of factor on the distribution of a distribution of a named sessile given species organism. Examples include daisies in a school playing field, epiphytes on the bark of a tree and limpets on a rocky shore. Use of the technique to estimate the size of a population of woodlice in a garden or school playground.
practical that includes that activity. The list below shows the apparatus and techniques that are covered by one activity only and alternatives to the required practical. Note: there is a possibility that the student could be asked questions about the required activity in written papers that would not be fully understood by carrying out the alternative. This should be considered when deciding whether to repeat the required activity. Biology If a student misses this required practical activity… …they won’t have covered this apparatus and technique. Other practicals within an Biology course involving this skill 2. Preparation of stained squashes of cells from plant root tips; set-up and use of an optical microscope to identify the stages of mitosis in these stained squashes and calculation of a mitotic index. d. use of light microscope at high power and low power, including use of a graticule Examination of permanent mounts of any tissue, related to specification content, in students use both high- and low-power objectives of an optical microscope and use a stage micrometer and eyepiece graticule to measure the actual size of cells. 7. Use of chromatography to investigate the pigments isolated from leaves of different plants, eg leaves from and shade-intolerant plants or leaves of different colours. g. separate biological compounds thin layer/paper chromatography or electrophoresis Separation of any aqueous mixture related to specification content, eg, sugars or amino acids, by paper or thin layer chromatography. Extraction of 'chlorophyll' from a plant or alga and separation of its constituent pigments by paper or thin layer chromatography. Separation of DNA fragments by electrophoresis. 12. Investigation into the effect of a named environmental factor on the distribution of a given species k. use sampling techniques in fieldwork Use of random quadrats to investigate the pattern of distribution of a named sessile organism. Examples include daisies in a school playing field, epiphytes on the bark of a tree and limpets on a rocky shore. Use of the technique to estimate the size of a population of woodlice in a garden or school playground. shade-
aqa-practical-hand-book-requirements.docx