A plant cuticle is a protecting film covering the epidermis of leaves, young shoots and other aerial plant organs without periderm. It consists of lipid and. A gametophyte is a stage in the life cycle of plants and algae that undergo alternation of generations. It is a haploid multicellular organism that develops from a. ADVERTISEMENTS Here are your useful notes on Anthocerotopsida The class Anthocerotopsida Anthocerotae consists of a single order, the Anthocerotales and a single. Plant cuticle Wikipedia. Water beads on the waxy cuticle of kale leaves. A plant cuticle is a protecting film covering the epidermis of leaves, young shoots and other aerial plant organs without periderm. Consider the following four statements whether they are correct or wrong a The sporophyte in liverworts is more elaborate than that in mosses. ADVERTISEMENTS Experiment to Observe Diversity of Plants Experiment Objective To study the characteristics of Spirogyra, Agaricus, Moss, Fern, Pinus either with. RESOURCES FOR QUEENSLAND STUDENTS TEACHERS DEADLY EEI IDEAS Ideas for Year 11 and 12 Biology Extended Experimental Investigations. Horse And Feather Tee'>Horse And Feather Tee. From Dr Richard Walding, BAppSc. It consists of lipid and hydrocarbon polymers impregnated with wax, and is synthesized exclusively by the epidermal cells. DescriptioneditThe plant cuticle is a layer of lipid polymer impregnated with waxes that is present on the outer surfaces of the primary organs of all vascular land plants. It is also present in the sporophyte generation of hornworts, and in both sporophyte and gametophyte generations of mosses2 The plant cuticle forms a coherent outer covering of the plant that can be isolated intact by treatment of plant tissue with enzymes such as pectinase and cellulase. CompositioneditThe cuticle is composed of an insoluble cuticular membrane impregnated by and covered with soluble waxes. Cutin, a polyesterpolymer composed of inter esterified omega hydroxy acids which are cross linked by ester and epoxide bonds, is the best known structural component of the cuticular membrane. The cuticle can also contain a non saponifiable hydrocarbon polymer known as Cutan. The cuticular membrane is impregnated with cuticular waxes6 and covered with epicuticular waxes, which are mixtures of hydrophobicaliphatic compounds, hydrocarbons with chain lengths typically in the range C1. C3. 6. 7FunctionseditThe primary function of the plant cuticle is as a water permeability barrier that prevents evaporation of water from the epidermal surface, and also prevents external water and solutes from entering the tissues. In addition to its function as a permeability barrier for water and other molecules prevent water loss, the micro and nano structure of the cuticle confer specialised surface properties that prevent contamination of plant tissues with external water, dirt and microorganisms. Aerial organs of many plants, such as the leaves of the sacred lotus Nelumbo nucifera have ultra hydrophobic and self cleaning properties that have been described by Barthlott and Neinhuis 1. The lotus effect has applications in biomimetic technical materials. Dehydration protection provided by a maternal cuticle improves offspring fitness in the moss Funaria hygrometrica2 and in the sporophytes of all vascular plants. In angiosperms the cuticle tends to be thicker on the top of the leaf adaxial surface, but is not always thicker. Gametophyte Of Funaria' title='Gametophyte Of Funaria' />The leaves of xerophytic plants adapted to drier climates have more equal cuticle thicknesses compared to those of mesophytic plants from wetter climates that do not have a high risk of dehydration from the under sides of their leaves. The waxy sheet of cuticle also functions in defense, forming a physical barrier that resists penetration by virus particles, bacterial cells, and the spores and growing filaments of fungi. EvolutioneditThe plant cuticle is one of a series of innovations, together with stomata, xylem and phloem and intercellular spaces in stem and later leaf mesophyll tissue, that plants evolved more than 4. Together, these features enabled upright plant shoots exploring aerial environments to conserve water by internalising the gas exchange surfaces, enclosing them in a waterproof membrane and providing a variable aperture control mechanism, the stomatal guard cells, which regulate the rates of transpiration and CO2 exchange. ReferenceseditKolattukudy, PE 1. Biosynthetic pathways of cutin and waxes, and their sensitivity to environmental stresses. In Plant Cuticles. Ed. by G. Kerstiens, BIOS Scientific publishers Ltd., Oxford, pp 8. Budke, J. M., Goffinet, B. Jones, C. S. 2. 01. Dehydration protection provided by a maternal cuticle improves offspring fitness in the moss Funaria hygrometrica. Annals of Botany doi 1. Holloway, PJ 1. 98. The chemical constitution of plant cutins. In Cutler, DF, Alvin, KL and Price, CE The Plant Cuticle. Academic Press, pp. Stark, RE and Tian, S 2. The cutin biopolymer matrix. In Riederer, M Mller, C 2. Biology of the Plant Cuticle. Blackwell PublishingTegelaar, EW, et al. Scope and limitations of several pyrolysis methods in the structural elucidation of a macromolecular plant constituent in the leaf cuticle of Agave americana L., Journal of Analytical and Applied Pyrolysis, 1. Jetter, R, Kunst, L Samuels, AL 2. Composition of plant cuticular waxes. In Riederer, M Mller, C 2. Biology of the Plant Cuticle. Blackwell Publishing, 1. Baker, EA 1. 98. Chemistry and morphology of plant epicuticular waxes. In Cutler, DF, Alvin, KL and Price, CE The Plant Cuticle. Academic Press, 1. Barthlott, W Neinhuis, C 1. Gorillaz Dare Acapella. Purity of the sacred lotus, or escape from contamination in biological surfaces. Planta 2. 02, 1 8Freeman, S 2. Biological Science. Prentice Hall, Inc., New JerseyRaven, J. A. 1. 97. 7 The evolution of vascular land plants in relation to supracellular transport processes. Advances in Botanical Research, 5, 1. Senior Biology Deadly Extended Experimental Investigations. RESOURCES FOR QUEENSLAND STUDENTS TEACHERS DEADLY EEI IDEAS Ideas for Year 1. Biology Extended Experimental Investigations. From Dr Richard Walding, BApp. Sc, MSc, MPhil, Ph. D, FAIP, FRACI, CChem, Griffith University, Australia. Senior Physics teacher Moreton Bay College, Brisbane Senior Biology Chemistry teacher Moreton Bay College 2. Author New Century Senior Physics textbook by Oxford University Press. Email richardwalding. Many of the suggestions below involve the use of animals. Various laws apply to the use of animals in schools particularly any live non human vertebrate, that is fish, amphibians, reptiles, birds and mammals, encompassing domestic animals, purpose bred animals, livestock, wildlife, and also cephalopods such as octopus and squid. For some further advice go to Use of Animals note at the end. OPEN INQUIRY EEI In most Queensland schools the Year 1. EEI provides students with a limited range of research questions to investigate, usually drawn from a single unit eg plants. This allows students to focus on the process and techniques of investigation and the subsequent reporting. The examples from Nanango State High and Moreton Bay College in Plant Options below are of this type. However, in Year 1. These Open Inquiry EEIs may provide more ownership, engagement and deeper understanding for the students but do place a bigger demand on resources and laboratory management. However, many teachers have found strategies to manage this should they choose to opt for a Open EEIs. An example of an Open Inquiry EEI can be downloaded here Nanango SHS Year 1. Open EEI. A Materials Requisition Form accompanies this document. My thanks to Biology teachers from Nanango for sharing this. SAFETY Risk Assessment in an EEI School. S have implemented various forms of Risk Assessment for their science laboratory or practical work. Examples of Risk Assessment forms can be found in the tasks available on this page. A comprehensive form developed over several years by Urangan SHS can be found here Risk Assessment Form. It is only an example and should not be assumed to necessarily meet the legal and safety obligations of any particular school or situation. TWO MAIN APPROACHES FOR AN EEI In general there are two main methods used in senior high school EEIs. They are The method of artificial variation where you manipulate one variable to see the effect on the other and keeping the rest constant For example, what is the effect of temperature the manipulated or independent variable, IV on the enzyme digestion of starch the dependent variable, DV. The method of concomitant variation where some naturally occurring variation in some condition Variable 1 is correlated against some other condition Variable 2. This is also called a correlation method. You can think that nature has manipulated the variables but it is still appropriate to class one as dependent and one as independent. For example, do young leaves have the same density and distribution of stomata as older leaves or how does temperature IV in a natural environment affect stoma opening DV In this second case you do not need you to control the environmental temperature, but you do need to measure the DV at different temperatures. The difficulty with the second approach is the control of other potentially influential variables such as humidity as you have to take what you get. However, that does not preclude the variables in relationship being considered the IV and DV or being graphed as such. One way to address the confounding variables eg humidity is to collect data on the other variable as well. That is, call the stomatemperature data Part I, and call the stomahumidity data Part 2. You can run the statistics on each pair separately, but, for students who are not that stats savvy then they could look for interactions between them at a visual level. My thanks to Marilyn Love, Science Department, All Hallows School, Brisbane for this example. FOOD TECHNOLOGY OPTIONSDoes the amount of bacterial growth in food differ according to its preparation or handling Although some micro organisms are deliberately used to make foods such as yoghurt and cheese, other microbes spoil food. Food, as well as meeting the nutritional requirements of humans, will also meet the nutritional needs of a vast range of micro organisms. These microbes will multiply rapidly in food, given the appropriate conditions such as temperature, p. H and moisture. The flavour, aroma and texture will ultimately be affected. Microbial contamination accounted for 3. Food Standards Australia New Zealand FSANZ between 1 January 1. December 2. 00. 4. Of these recalls, 4. Listeria monocytogenes contamination 1. Salmonella contamination and 1. Escherichia coli contamination Food Standards 2. Those most affected by food poisoning are the elderly, the young and immune suppressed individuals. This EEI is suggested by Biology teacher Sylvia Hicks from St Aidans College, Corinda. Effects of different anti microbials on bacterial growth Joseph Lister first introduced aseptic surgery in 1. C6. H5. OH as a germicide. He was able to reduce mortality of post operative surgery by up to 4. Since then the control of growth by antimicrobial compounds has grown into a multi billion dollar industry. A good EEI is to assess the effect of a variety of antimicrobial disinfectants on bacterial growth. Charmaine Keal HOD Science at Tullawong State High School offered this advice the most popular is testing the effects of different anti microbials on bacterial growth. Our labbies prepare the plates and order in E. Students then put a wash of E. Small paper discs like out of a hole punch are sterilised and then soaked into different anti microbials. The discs are placed onto the agar plates and then into the incubator for a couple of days. If the anti bacterial is effective there is a clear ring around the disc where the E. Students have used the width of this ring to indicate effectiveness and to collect quantitative data. The experiment can work quite well keen students have then researched the active compounds within the antibiotic, how they act upon the bacteria and link to the results observed. Common antibacterials are alcohols eg ethanol, isopropyl alcohol, synthetic detergents QAC quaternary ammonium compounds or phenols. No single disinfectant is ideal. Each has its advantages and disadvantages. For example, phenols sterilise well but are corrosive and toxic. Detergents and 7. At Mt Maria College, Enoggera, Brisbane, the Science Co ordinator Shan Wainwright also uses multi disks impregnated with antibiotics. Risk assessment including disposal of waste is vital. The images in the diagram to the right were prepared by Dr Dennis Kunkel of Dennis Kunkel Microscopy Inc. Over years Dennis has assembled a vast collection of these micrographs, many of which have been colorized and can be viewed on his website. Images Copyright Dennis Kunkel Microscopy, Inc. Some photos below taken from the EEI of a Yr 1. Biology student at Our Ladys College, Annerley, Brisbane.