Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download B2pt8 draft
Document related concepts
Transcript
Draft Standard Biology 2.8: Investigate biological material at the microscopic level Resource Title: The Micro World Credits: 3 Teacher guidelines The following guidelines are supplied to enable teachers to carry out valid and consistent assessment using this internal assessment resource. Read also the Explanatory Notes for Achievement Standard Biology 2.8. These notes contain information, definitions, and requirements that are crucial when interpreting the standard and assessing against it. Context/Setting This activity requires students to investigate biological material at the microscopic level. The context is the “micro world” of plants and unicellular organisms. Through practical microscope work students will investigate biological material by preparing specimens to view under light microscopes and recording their observations as biological diagrams. Following their practical work students will write a report that gives reasons for how or why observed specialised features enable the cells to effectively carry out their specific function(s). Conditions The biological diagrams should come from several practical sessions completed by the students. These sessions must include two different plant tissues and one unicellular organism; suitable specimens include silverbeet leaves, rhubarb leaves, daffodil or onion shoots, filamentous green algae, Elodea, Paramecium. These sessions may include preparation techniques such as staining, use of cavity slides, use of cellulose, epidermal tear, cutting transverse sections. Students should work individually to prepare specimens, view under a light microscope and record observations as biological drawings. Students should hand in their biological drawing(s) at the end of each session. The written report is to be completed individually in exam conditions; students will need access to their biological drawings. It is suggested that this will take 1 class period. Resource Requirements Students will need access to light microscopes, glass slides (flat and cavity), cover slips, suitable stains such as iodine, droppers, tweezers, toothpicks, blotting paper. They will need to be provided with suitable plant material and unicellular organisms for viewing under a light microscope. Paramecium can be purchased through outlets such as “Biosuppliers” and is easily cultured by keeping in a jar of water to which a handful of straw has been added, keep in a dark, even temperature environment. Suitable plant material is easily purchased at supermarkets or found in school / staff gardens. It may be possible to complete the practical sessions at a local university or polytechnic as part of a fieldtrip. A clearfile for each student would be helpful for teacher collection of completed biological drawings. Draft Standard Biology 2.8 (AS91160): Investigate biological material at the microscopic level Resource Title: The Micro World Credits: 3 Achievement Achievement with Merit Investigate biological material at the microscopic level Investigate in-depth biological material at the microscopic level Student Instructions Sheet Introduction This assessment activity requires you to prepare and view biological material under a light microscope and record your observations as biological drawings. You will then write a report giving reasons for how or why observed specialised features enable the cells to effectively carry out their specific function(s). When writing your report you will have access to your completed biological drawings. Insert conditions for assessment here e.g. Practical sessions will take place on <dates> and will be <time> in duration each The report writing session will take place on <date> and will take 1 class period All work is to be completed individually Part A - Practicals There is no need to include all practicals below. Teachers should select two different plant tissues and one unicellular organism and delete the rest Silverbeet leaf tear Rhubarb leaf tear Onion bulb epidermis Onion shoot transverse section Daffodil shoot/leaf transverse section Filamentous green algae Elodea Paramecium For each practical you will need to – Prepare the biological material for viewing under a light microscope View specimen using a light microscope correctly so details of cell structures can be seen Record your observations as a biological drawing on the paper provided Ensure the marker has checked your slide before removing it from the stage of microscope Part B – Written Report For each of your biological drawings in Part A Describe the function of the cell/tissue Relate the labelled features/organelles to the function Explain how or why these features enable the cells to effectively carry out their specific functions. Draft Standard Biology 2.8 (AS91160): Investigate biological material at the microscopic level Part A: Insert tissue/organism name here (there needs to be 3 of these) Student Name ________________________________ Date ____________ Space for biological diagram: Draft Standard Biology 2.8 (AS91160): Investigate biological material at the microscopic level Part B – Written Report Insert tissue/organism name here (there needs to be 3 of these sheets) Describe the function of the cell/tissue __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ From your biological drawing choose TWO features/organelles Feature 1 _________________________________________________________________ Explain how or why this feature/organelle enables the cell(s) to effectively carry out their specific function. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ Feature 2 _________________________________________________________________ Explain how or why this feature/organelle enables the cell(s) to effectively carry out their specific function. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ Assessment Schedule: Biology 2.8: Investigate biological material at the microscopic level Evidence/Judgments for Achievement Credits: 3 Evidence/Judgments for Achievement with Merit Investigate biological material at the microscopic level Investigate in-depth biological material at the microscopic level Evidence should come from biological drawings and report Evidence should come from biological drawings and report Prepared slide allows identifiable features to be determined i.e. thin, flat specimen/correct stain/few air bubbles/no excess liquid/cover slip present Plant Tissue 1 Plant Tissue 2 Unicellular Organism Viewing under light microscope allows identifiable features to be determined i.e. suitable magnification used/focused Plant Tissue 1 Plant Tissue 2 Unicellular Organism Use a biological drawing to record observations i.e. use of conventions such as use of pencil, appropriate size of drawing, solid lines drawn, correct title and magnification, correct feature/organelle labels (at least 3) e.g. pencil used, title, magnification and labels correct but cell nucleus and cell shape does not reflect what seen at 400X mag Plant Tissue 1 Plant Tissue 2 Unicellular Organism Prepared slide allows identifiable features to be determined i.e. thin, flat specimen/correct stain/few air bubbles/no excess liquid/cover slip present (as for Achieve) Viewing under light microscope allows identifiable features to be determined i.e. suitable magnification used/focused (as for Achieve) Use a biological drawing to record observations that are consistent with material being viewed i.e. recognizable shape/proportions, inclusion of typical organelles consistent with magnification e.g. accurately reflects what seen at 400X mag for Elodea Plant Tissue 1 Plant Tissue 2 Unicellular Organism State function(s) of TWO features/organelles and correctly relate to function of tissue/organism e.g. Stomata are where gases enter and exit leaves as part of photosynthesis in the leaf. Guard cells open and close stomata (control stomata size) during photosynthesis. Plant Tissue 1 Plant Tissue 2 Unicellular Organism Explain how or why TWO features/organelles enable the tissue/organism to effectively carry out their specific function(s) e.g. Onion epidermal cells have a cell wall which is used for support. This is needed as the cells are storing water and nutrients and there is turgor pressure. Without cell walls the epidermal cells would burst (lyse). Onion epidermal cells do not have chloroplasts, which is because the tissue involved is to do with storage of energy as an underground bulb. This means it is not exposed to light and therefore chloroplasts would have no use as chloroplasts convert light energy using photosynthesis. Plant Tissue 1 Plant Tissue 2 Unicellular Organism TWO of the three needed All criteria must be met for Achievement All criteria must be met for Merit Name: Class: Signature: Date: Grade:
