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Cell Size and Scale

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

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

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Pictures of Pennies Hi, I'm Mitch Fincher and these pages are from a talk I gave while a Civil Engineering student at Texas Tech University. The following is the basic pattern for building cantilevered structures with Pennies. Although it looks trivial, we can build amazing structures with these pillars. All penny columns are ten pennies high, a "stack". What you burn Next: What comes outUp: The Rubber Bag Previous: What goes in ``What you burn'' is the number of calories your body uses to provide the energy for everything you do, from heartbeats and breathing to running a marathon. The daily calorie requirement varies quite a bit from person to person depending on size, shape, basic metabolic rate, and degree of physical activity. 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.

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64 Things Every Geek Should Know. The term ‘geek’, once used to label a circus freak, has morphed in meaning over the years. What was once an unusual profession transferred into a word indicating social awkwardness. As time has gone on, the word has yet again morphed to indicate a new type of individual: someone who is obsessive over one (or more) particular subjects, whether it be science, photography, electronics, computers, media, or any other field. A geek is one who isn’t satisfied knowing only the surface facts, but instead has a visceral desire to learn everything possible about a particular subject. A techie geek is usually one who knows a little about everything, and is thus the person family and friends turn to whenever they have a question. If you’re that type of person and are looking for a few extra skills to pick up, or if you’re a newbie aiming to get a handhold on the honor that is geekhood, read on to find out what skills you need to know.

A Sense of Scale: Absolute Zero By Glenn Elert Posted 01.08.08 NOVA At roughly minus 460°F, absolute zero is abysmally cold, yet at least we can imagine it. Being only a few hundred degrees below zero, it's in the realm of something we can put our minds around. This is not true of the opposite of absolute zero, the theoretical highest possible temperature. In conventional physics, this is approximately 100 million million million million million degrees. In this interactive, get a taste of temperatures from absolute zero to absolute hot, and see why, for instance, even the core of the sun is relatively "chilly" compared to what many physicists believe the temperature of the universe was an instant after the Big Bang.

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