Search results for: 'Ear'

Watch Later 0:58

By: HWC, Views: 7362

■ Shared electrons in the outermost orbital form bonds. These electrons are called valence electrons. ■ Valence electrons are disrupted and can be rearranged into a new bond. ■ The energy necessary to start a reaction and break bonds is called the activation energy. ■ Reactants have...

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A timeline of the teeth (Explained - No Audio)

By: HWC, Views: 6803

Although most babies don't appear to have any teeth when they are born, they are in fact already well developed out of sight beneath the gum. The first molars erupt at about 12-14 months. The canines follow at about 16-18 months . By 3 years old, the second molars have usually erupted, c...

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Oral Hygiene & Braces Animation

By: HWC, Views: 7372

Caring for Your Retainer Retainers, just like your teeth collect plaque, bacteria and food particles. You should clean your retainer everyday! Keep your retainer soaking when it is not in your mouth. Use a mouthwash rinse to freshen it up and keep it free of bacteria. Keep your retainer away fr...

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Stages of Mitosis - Prophase, Prometaphase, Metaphase, Anaphase & Telophase

By: HWC, Views: 7598

In mitosis, the nucleus divides to produce two nuclei that are genetically identical to each other and to the parent nucleus. To prepare for division, the DNA replicates in the preceding interphase. Although the chromosomes are not yet compacted and visible as discrete bodies, we illustrate them ...

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Hierarchical Sequencing Method - Sequence Tagged Sites

By: HWC, Views: 7136

In the hierarchical sequencing method, researchers begin by collecting cells. In humans, each cell contains 23 pairs of chromo-somes. Here we specifically track the DNA from just one of the 23 pairs. Chromosomes have a series of unique DNA sequences, called sequence-tagged sites (STSs), that a...

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SNP Polymorphysim Microarray Chip - How to Test a Person's DNA

By: HWC, Views: 7181

To test a person's DNA, a researcher first needs a source of tissue. Most of the cells in a blood sample are red blood cells, which lack nuclei, but there are also a number of white blood cells, which do contain nuclei and chromosomal DNA. If we could see a particular DNA sequence in these cel...

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The Hypothalamus: The Body's Thermostat (Human Thermostat)

By: HWC, Views: 7106

Normal body function requires a relatively constant body temperature, which is regulated by the body's thermostat, a region of the brain called the hypothalamus. The hypothalamus generates a temperature set point for the body and appears to be the major site for the integration of temperature inf...

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Pasteur's Experiment

By: HWC, Views: 7259

Louis Pasteur designed a procedure to test whether sterile nutrient broth could spontaneously generate microbial life. To do this, he set up two experiments. In both, Pasteur added nutrient broth to flasks, bent the necks of the flasks into S shapes, and then boiled the broth to kill any existing...

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Four Giant Convection Cells oF Earth

By: HWC, Views: 7212

Earth Has Four Giant Convection Cells Earth's climates range from dry and cold at the poles to wet and warm at the equator. These climates are dictated largely by the amount of solar radiation that a region receives. Solar radiation warms the Earth and the surrounding air, setting up convection c...

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