Cell Size and Scale Some cells are visible to the unaided eye The smallest objects that the unaided human eye can see are about 0.1 mm long. That means that under the right conditions, you might be able to see an ameoba proteus, a human egg, and a paramecium without using magnification. A magnifying glass can help you to see them more clearly, but they will still look tiny. Smaller cells are easily visible under a light microscope. It's even possible to make out structures within the cell, such as the nucleus, mitochondria and chloroplasts. To see anything smaller than 500 nm, you will need an electron microscope. Adenine The label on the nucleotide is not quite accurate. How can an X chromosome be nearly as big as the head of the sperm cell? No, this isn't a mistake. The X chromosome is shown here in a condensed state, as it would appear in a cell that's going through mitosis. A chromosome is made up of genetic material (one long piece of DNA) wrapped around structural support proteins (histones). Carbon
Concept Cartoons These concept cartoons were developed by Dianne Anderson and Kathleen Fisher (2002) as prompts for eliciting discussion about ideas in evolution. They can also be used as assessment tools. The cartoons are best suited for college non-majors and pre-college classes. Cartoons can be downloaded in PDF format and can be transferred to transparencies or paper copies so long as the copyright notation to Anderson and Fisher is retained. For comments or questions please contact dianneanderson@pointloma.edu kfisher@sciences.sdsu.edu Nouvelle plateforme LUMNI ETUDIANT Pour Lumni, le respect de votre vie privée est une priorité Vous pouvez exprimer votre consentement à ces traceurs en cliquant sur le bouton « tout accepter », les refuser en fermant cette fenêtre à l’aide de la croix, ou vous informer sur le détail de chaque finalité et exprimer votre choix pour chacune d’entre elles en cliquant sur « paramétrer ». Vous pouvez modifier vos choix à tout moment en cliquant sur « Gérer mes traceurs » en bas des pages de ce site. Vous pouvez aussi consulter nos conditions générales d’utilisation pour plus d’informations. Pour Lumni, le respect de votre vie privée est une priorité Vous pouvez exprimer votre consentement à ces traceurs en cliquant sur le bouton « tout accepter », les refuser en fermant cette fenêtre à l’aide de la croix, ou vous informer sur le détail de chaque finalité et exprimer votre choix pour chacune d’entre elles en cliquant sur « paramétrer ».
Ornithos Atlantic Rainforest Webcam World Land Trust uses cookies to make all features of the website work effectively, and they are essential if you wish to donate online. Some cookies on this site are essential, and the site won't work as expected without them. These cookies are set when you submit a form, login or interact with the site by doing something that goes beyond clicking on simple links. We also use some non-essential cookies to anonymously track visitors or enhance your experience of the site. If you're not happy with this, we won't set these cookies but some nice features of the site may be unavailable. By using our site you accept the terms of our Privacy Policy. (One cookie will be set to store your preference) (Ticking this sets a cookie to hide this popup if you then hit close. About this tool About Cookie Control
Top 10 Amazing Biology Videos | Wired Science Cyborgs, stem cells, glowing mice, and hilarious music videos are great reasons to be excited about biology. Here are some of our favorite clips from the life sciences. 10. Immune Cell Chasing a BacteriumIt may look like the predecessor to Pac Man, but this vintage clip shows a neutrophil wending its way through a crowd of red blood cells to destroy its bacterial nemesis. 9. 8. 7. 6. 5. 4. 3. 2. 1. Last week, regenerative medicine researchers announced that they have grown a new windpipe for a woman who was crippled by tuberculosis. See Also:
Cell wall - Wikipedia, the free encyclopedia.url The material in the cell wall varies between species, and can also differ depending on cell type and developmental stage. In bacteria, peptidoglycan forms the cell wall. Archaean cell walls have various compositions, and may be formed of glycoprotein S-layers, pseudopeptidoglycan, or polysaccharides. Fungi possess cell walls made of the glucosamine polymer chitin, and algae typically possess walls made of glycoproteins and polysaccharides. Properties[edit] Diagram of the plant cell, with the cell wall in green. The cell wall serves a similar purpose in organisms that possess them. Rigidity of cell walls[edit] The rigidity of the cell walls is often overestimated. Think of the cell wall as a wicker basket in which a balloon has been inflated so that it exerts pressure from the inside. The rigidity of the cell wall thus results in part from inflation of the cell contained. Permeability[edit] Cell wall evolution[edit] Plant cell walls[edit] Layers[edit] Composition[edit] Formation[edit]
Evolution Games, Labs, Acivities Evolution Living things change over time! Learn about and review the mechanisms that cause genetic change in populations, as well as several lines of evidence for change over time. Also, explore how organisms are classified into groups and named. Evolution Video Games, Virtual Labs & Activities Snurfle Islands! Create a Snurfle with awesome adaptations and test his survival in several challenging island environments! Angry Aliens: Evolution Angry aliens are invading earth!
Evaluer - Ressources sur les barèmes curseurs Evaluation à l’aide de barèmes curseurs Un groupe de professeurs de SVT de l’académie de Strasbourg a créé, avec l’inspection pédagogique régionale, une série de « barèmes curseurs ». Ces barèmes, volontairement divers dans leur forme, ciblent uniquement les exigibles. Selon les barèmes mais aussi selon les pratiques pédagogiques de chacun, les évaluations par le professeur, les auto-évaluations et/ou les évaluations entre pairs peuvent être plus ou moins pertinentes. Même si un barème chiffré est présent, l’évaluation sans note est possible car les fichiers sont fournis en version modifiable. Parmi tous les possibles, l’évaluation des gestes techniques, de l’oral et des traces écrites a fait l’objet de productions (fichiers disponibles dans la liste ci-dessous). Le cas du dessin d’observation est détaillé en annexe dans l'article suivant (cliquez ici). Evaluer les gestes techniques Evaluer les traces écrites (cahiers d’élèves) Evaluer un diaporama Evaluer l’oral
Biology Teaching & Learning Resources. Educational articles, drawings, experiments & PowerPoint presentations by D G Mackean Cellular Respiration Demo using Gummy Bears - Exciting!! This is a very simple demonstration that makes an impact. It illustrates energy release that occurs quickly. In the demonstration, Mr. Carter (the other science teacher at my school) visually reinforces the necessity of cellular metabolism’s small-step oxidation of glucose instead of releasing it all at once. The materials you will need for this demonstration are as follows: Approximately 1 tablespoon of Potassium ChlorateLarge test tubeGummy bear (or any other gummy animal)Fume hood (or any system to allow for the fumes to escape without engulfing the room)Eye protection (Lab Goggles, etc) The solid should be heated until it melts, and then the gummy bear can be dropped in. The products of the reaction should be potassium chloride (white deposit near the mouth of the test tube) as well as varying amounts of soot or charred gummy bear if not all of it is used up in the reaction. This kind of “all at once” release of energy would be catastrophic in a living organism.
Animal Cell Anatomy - EnchantedLearning.com.url Advertisement. EnchantedLearning.com is a user-supported site. As a bonus, site members have access to a banner-ad-free version of the site, with print-friendly pages.Click here to learn more. (Already a member? The cell is the basic unit of life. The following is a glossary of animal cell terms: cell membrane - the thin layer of protein and fat that surrounds the cell. Related Pages: 100 Very Cool Facts About The Human Body The Brain The human brain is the most complex and least understood part of the human anatomy. There may be a lot we don’t know, but here are a few interesting facts that we’ve got covered. Nerve impulses to and from the brain travel as fast as 170 miles per hour. Ever wonder how you can react so fast to things around you or why that stubbed toe hurts right away? It’s due to the super-speedy movement of nerve impulses from your brain to the rest of your body and vice versa, bringing reactions at the speed of a high powered luxury sports car.The brain operates on the same amount of power as 10-watt light bulb. Hair and Nails While they’re not a living part of your body, most people spend a good amount of time caring for their hair and nails. Facial hair grows faster than any other hair on the body. Internal Organs Though we may not give them much thought unless they’re bothering us, our internal organs are what allow us to go on eating, breathing and walking around. Bodily Functions Senses
100 activités génériques de pédagogie active - Fiches complètes - Gratuit Voici une ressource pédagogique de qualité, accessible à tous et proposée comme aide pédagogique pour les profs de Polytechnique Montréal, une école affiliée de l'Université de Montréal. Les enseignants en génie sont avant tout des experts de leur domaine, mais pas nécessairement de la pédagogie. Aussi le service pédagogique IMPAct (Innovation en moyens pédagogiques d’apprentissage actif) a préparé des fiches d'activités génériques, qui peuvent être utilisées comme approche pédagogique dans n'importe quelle matière. Ces fiches sont conçues pour des professeurs qui ne sont pas des pédagogues mais qui apprécieront le devenir. Améliorer la qualité de l'enseignement Les principes du travail intellectuel demeurent les mêmes, peu importe l'âge, l'expérience ou la matière abordée. Même si au départ on s'adresse à une clientèle universitaire, ces fiches peuvent être utilisées aussi bien au primaire qu'à l'université. Situations et besoins pédagogiques variés Vignettes de pédagogie active
Biology For Kids - KidsBiology.com