The Genetic Gamesmanship of a Seven-Sexed Creature | Discoblog What could be better than two types of sexes? For one organism, the answer isn’t three, but seven! And to top it off, these seven sexes aren’t evenly distributed in a population, although researchers have now developed a mathematical model that can accurately estimate the probabilities in this crap-shoot game of sexual determination. Meet Tetrahymena thermophila, which in addition to its seven different sexes—conveniently named I, II, III, IV, V, VI, and VII—has such a complex sex life that it requires an extra nucleus. The other odd thing about this one-celled wonder is that the population of the seven sexes are skewed, leading Unversity of Houston researcher Rebecca Zufall and her colleagues to ask: What gives? To answer that question, they created mathematical models of T. thermophila populations, and discovered that different versions of the same gene, or alleles, gave advantages to different sexes. Related Content: 80beats: What Makes a Boy Lizard? Image: Wikimedia Commons / Ayacop
Preschool science activities How to nurture your child's interest in the natural world © 2008 -2012 Gwen Dewar, Ph.D., all rights reserved Can we design better preschool science activities? In the article below, I review the advice of educational and cognitive psychologists about preschool science education. Floating and Boating is a set of science activities that encourage kids to play in the water, explore the concept of buoyancy, and make some cool contraptions. Dirt Lab is a set of activities that encourages kids to investigate the properties of dirt and mud. Animal tracking offers young children opportunities to exercise their spatial and scientific reasoning skills. Experiments with ice cubes introduce kids to aspects of the scientific method, as does this Brick-making activities allow kids the opportunity to make and test predictions. Activities for encouraging the use of science tools may motivate kids to take measurements and develop fine motor coordination. Preschool science activities: • how living things move
Practical Biology This website is for teachers of biology in schools and colleges. It is a collection of experiments that demonstrate a wide range of biological concepts and processes. Experiments are placed within real-life contexts, and have links to carefully selected further reading. Each experiment also includes information and guidance for technicians. Biology is a practical science. We have published a new set of resources to support the teaching of practical science for Key Stages 3-5. Unfortunately, we are unable to respond to questions from teachers, technicians or students on how to use the experiments on this website. Biologija.com.hr - Vijesti - Biologija - Zašto je nekih vrsta na Zemlji mnogo, a nekih malo? Na svijetu postoji više od 400.000 vrsta kornjaša (skupina kukaca), a samo dvije vrste tuatara ili premosnika, rođaka zmija i guštera, koji živi na sjeveru Novog Zelanda. Zašto evolucija stvara ''pobjednike',' kao što su sisavci i mnoge vrste ptica i riba, a zašto ''gubitnike'' i dalje je jedno od središnjih pitanja evolucijske biologije. Premosnici (Sphenodon) su jedini recentni rod reda Rhynchocephalia u razredu gmazova. Pored toga, jedini su recentni predstavnici porodice Sphenodontidae. Često ih se naziva i "živim fosilima", jer se njihovo postojanje može slijediti fosilnim nalazima unatrag sve do razdoblja trijasa, u vrijeme prije oko 200 milijuna godina. Obitelj premosnika predstavljaju samo dvije vrste, Sphenodon punctatus (naslovna fotografija) i, još rjeđa, Sphenodon guntheri. Znanstvenici su pretpostavljali da je vrijeme glavni čimbenik koji utječe na broj vrsta - što su neke životinjske i biljne linije starije od ostalih, iz njih se mnogo više vrsta imalo vremena razviti.
Environmental Science - AP Environmental Science - Homework Help Can I take a course at HippoCampus for credit? How do I enroll in a course at HippoCampus? Are there any fees to take your courses? How do I make a comment or ask a question? How do I get individual help with my homework assignment? What are the preferred texts? How can I use HippoCampus in my classroom? How can I use HippoCampus in my home school? Can I use the resources you have available for my homeschoolers? Do you know of any wet lab resources to accompany HippoCampus content? Is there a script, app, or something that can be used to track student use of HippoCampus? Can I share my HippoCampus content with my fellow teachers? Can I download the video? Can I change the size of the video window? Why won't the Environmental Science animations play? What if my page scroll bars or "submit" button are not showing? I can't find closed captioning. Where does the content from your site come from? There is an error in the multimedia presentation. How do I report a course errata item? No. AP Course Ledger
Tree of Life | Wellcome Trust Rare and Precious Moments of Animal Life How interesting can animal life be is something which we can only guess. By looking these amazing photographs it seems that they have very funny and precious moments. Would you like to be monkey, or elephant, or maybe cat sometimes? Don’t worry if you do because this has happened all of us at least ones, for now enjoy these rare photos!
Home Don Slish Animations {*style:<b>Animations and Interactive Tutorials Produced by Dr. Donald F. Slish </b>*} This animation shows the molecular mechanisms of the control of cell division by tyrosine kinases and the inhibition of this by p53, when there is slight DNA damage. Other animations: RER protein folding Hypoxic effects on dopamine release Metabotropic Receptor activating an ion channel Ionotropic Receptor Receptor Regulation (Extended) Receptor Regulation (Short form) Amphetamines, Ecstasy, Cocaine, and LSD mechanisms Insulin Receptor Mechanism Phosphatidylinositol Kinase and actin polymerization Toxin of the Neuromuscular Junction Summation (threshold) Summation Cell Crawling - retrograde flow of actin Cell Crawling APC control of Metaphase - Anaphase transition TNF activation of Apoptosis Cargo Vesicle moving on a Microtubule Vesicle I Astral molecular motor Astral II Molecular motors used in mitosis Molecular Motors A basic electrical circuit
Brain, Brain Information Making sense of the brain's mind-boggling complexity isn't easy. What we do know is that it's the organ that makes us human, giving people the capacity for art, language, moral judgments, and rational thought. It's also responsible for each individual's personality, memories, movements, and how we sense the world. All this comes from a jellylike mass of fat and protein weighing about 3 pounds (1.4 kilograms). The brain's nerve cells are known as neurons, which make up the organ's so-called "gray matter." The cerebrum is the largest part of the brain, accounting for 85 percent of the organ's weight. The cerebrum has two halves, or hemispheres. Movement and Balance The second largest part of the brain is the cerebellum, which sits beneath the back of the cerebrum. The diencephalon is located in the core of the brain. The brain stem, at the organ's base, controls reflexes and crucial, basic life functions such as heart rate, breathing, and blood pressure.