Search results for: 'Four Giant Convection Cells oF Earth'

Watch Later 2:14

By: HWC, Views: 7060

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...

Watch Later 3:42

Photosynthesis and Van Helmont Experiment

By: HWC, Views: 7005

All energy on Earth comes from a star, the Sun. Light must travel 160 million kilometers to reach Earth where plants capture this light energy and convert it to chemical energy in the form of sugars. This biochemical process is called PHOTOSYNTHESIS. The summary equation for photosynthesis is ...

Watch Later 2:56

Diversity of Living Creatures - Charles Darwin & the Beagle's Voyage

By: HWC, Views: 7484

As we look around at the living creatures on Earth, we see a great amount of diversity. In some cases, the differences are quite noticeable, like the differences between plants and animals. Some differences are not as easy to see, like the differences between two species of lizard. How did all...

Watch Later 1:20

Miller's reaction chamber experiment Animation

By: HWC, Views: 1322

A simple diagram of Stanley Miller and Harold Urey's experimental apparatus. The lower portion of the apparatus was filled with water. The upper portion was filled with a mixture of gases that simulated the earth's early atmosphere. Examples are methane, ammonia, hydrogen and carbon dioxide. ...

Watch Later 2:48

Darwin's Observation (Fossils, Galapagos Islands & Africa ) and Natural Selection (Adaptive Traits)

By: HWC, Views: 7637

Along Darwin's voyage, he made many observations. Each one added to his understanding of how organisms change over time. Darwin was already familiar with fossils and knew that many fossils were very different from living organisms. But, also there were some fossils that were very similar to li...

Watch Later 1:00

Bacteriophage (Virus) - Mice Experiment

By: HWC, Views: 7467

Also known as phages, these viruses can be found everywhere bacteria exist including, in the soil, deep within the earth's crust, inside plants and animals, and even in the oceans. Bacteriophages (phages) are viruses of bacteria that can kill and lyse the bacteria they infect. ... The lethalit...

Watch Later 3:03

What Are Carbohydrates? Importance of Carbs & High Carb Food

By: HWC, Views: 7837

We hear a lot about carbohydrates in the news. Everybody seems to be on a low-carb diet. The news media often has stories on this diet fad, and companies are busy producing products with reduced carbohydrates. What's this fascination with carbohydrates? In a word: "Diet." The fact is that carb...

Watch Later 1:55

Metabolic Rate, Heat and Thermoregulation - response to heat and cold stresses

By: HWC, Views: 7969

• A neuron group in the anterior portion of the hypothalamus controls heat balance. • Neurons in the preoptic region of the hypothalamus integrate signals that come from thermoreceptors. • The temperature control center in the preoptic region propagates control signals to two other part...

Watch Later 0:40

Erythropoietin (EPO)

By: HWC, Views: 7254

■ Secreted by kidney cells when blood oxygen is low. ■ Targets cells in red bone marrow that will become red blood cells. ■ Promotes increased numbers of mature red blood cells. ■ More mature red blood cells carry more oxygen so blood oxygen level is restored to normal.

Search Results