background preloader

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 amoeba 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

https://learn.genetics.utah.edu/content/cells/scale/

Related:  ETLVKemiBiologie/EnseignementScienceChapitre 3 : La cellule vivante

Coronavirus Resource Center It is unknown whether a pregnant woman infected by the “SARS-CoV-2” virus can pass it to her fetus, called “vertical transmission.” However, infants born to mothers affected by COVID-19 have displayed adverse health outcomes such as respiratory distress. The scientists are still not sure whether these adverse outcomes are related or not to the COVID-19 infection in their mothers. Metagenomic RNA sequencing was used to first identify the coronavirus in a sample from a patient who had worked at the Wuhan food market. A draft genome sequence was made publicly available in the GenBank sequence repository on January 10th (last updated on January 17th). A rapid-response team from the Chinese Center for Disease Control and Prevention isolated and cultivated the coronavirus from bronchoalveolar lavage fluid of three patients and identified it as the probable source of the outbreak

6th Grade Science Projects for the Classroom or Science Fair Hands-on projects and experiments in the classroom bring science to life, sparking a desire in students to explore and learn. Whether you’re prepping for a science fair or looking to impress your class with a spectacular demonstration or two, these 6th grade science projects are sure to be winners. 1. Extract DNA from a strawberry.

Misconceptions about evolution Unfortunately, many people have persistent misconceptions about evolution. Some are simple misunderstandingsideas that develop in the course of learning about evolution, possibly from school experiences and/or the media. Other misconceptions may stem from purposeful attempts to misrepresent evolution and undermine the public's understanding of this topic. Browse the lists below to learn about common misconceptions regarding evolution, as well as clarifications of these misconceptions. You can also download a pdf of this section. MISCONCEPTION: Evolution is a theory about the origin of life.CORRECTION: Evolutionary theory does encompass ideas and evidence regarding life's origins (e.g., whether or not it happened near a deep-sea vent, which organic molecules came first, etc.), but this is not the central focus of evolutionary theory.

iCell App Launch Tool iPadiPhoneiPod TouchAndroidWeb-based iCell gives you an interactive, 3D view inside a cell. You can study cell structures using a dynamic and realistic virtual model. Included are examples of three types of cells: animal, plant, and bacteria. Biochemistry Biochemistry is one of the crossover fields of chemistry. Biochemists have to understand both the living world and the chemical world. Even if you don’t want to become a biochemist, you'll still have to understand atoms and molecules as a biologist. You'll also have to know about organic chemistry; a much bigger area of chemistry. The key thing to remember is that biochemistry is the chemistry of the living world. Plants, animals, and single-celled organisms all use the same basic chemical compounds to live their lives.

This awesome periodic table tells you how to actually use all those elements Thanks to high school, we’ve all got a pretty good idea about what’s on the periodic table. But whether you’re looking at something common like calcium, iron, and carbon, or something more obscure like krypton and antimony, how well do you know their functions? Could you name just one practical application for vanadium or ruthenium? Lucky for us, Keith Enevoldsen from elements.wlonk.com has come up with this awesome periodic table that gives you at least one example for every single element (except for those weird superheavy elements that don’t actually exist in nature).

Not an adaptation Misconceptions about natural selection and adaptation : Not an adaptation It's tempting to look for adaptive explanations for everything, from the shape of a flower petal, to the way your dog turns in a circle before it lies down to sleep, to your neighbor's strawberry blond hair. Biology 2e – Open Textbook Book Description Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology Games Games For Assessment Games are a good way of engaging our students. They can be also be used to motivate and energise students for learning as well as an AFL tool. There are a number of premade games below and these can be used in a variety of ways in the classroom. They can also be adapted to suit your individual class.

This awesome periodic table shows the origins of every atom in your body Here’s something to think about: the average adult human is made up of 7,000,000,000,000,000,000,000,000,000 (7 octillion) atoms, and most of them are hydrogen - the most common element in the Universe, produced by the Big Bang 13.8 billion years ago. The rest of those atoms were forged by ancient stars merging and exploding billions of years after the formation of the Universe, and a tiny amount can be attributed to cosmic rays - high-energy radiation that mostly originates from somewhere outside the Solar System. As astronomer Carl Sagan once said in an episode of Cosmos, "The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars.

High School Biology Experiment Ideas High school level biology covers all aspects of biology, including animals, plant life and humans. That should mean it’s easy to come up with a science fair project or a classroom research project, but the amount of topics sometimes makes it even harder. When you first start researching, you’ll find thousands of ideas and it’s difficult to decide which one is best for your situation. Provided that you know what you want to do and what your teacher or judges are looking for, it’s easy to come up with a great biology experiment.

Related:  Cellule