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Evolutionary tree of life Animation

By: HWC, Views: 1400

An evolutionary tree of life that reflects mainstream thinking about the connections among major lineages (bya = billions of years ago, mya = millions of years ago). By about 3.8 billion years ago, chemical and molecular evolution had produced the first living cells. The first major divergenc...

Mechanisms of capillary exchange

By: HWC, Views: 7890

■ The primary role of capillaries is to permit the exchange of nutrients and wastes between the blood and tissue cells (via interstitial fluid). ■ Oxygen and nutrients move from the blood to the cells. ■ Carbon dioxide and other wastes move from the cells to the blood. The three ba...

Methods of carbon dioxide transport - carbaminohemoglobin and bicarbonate ions

By: HWC, Views: 7794

• Carbon dioxide is transported three ways: • As bicarbonate ions in the plasma. • Bound to hemoglobin. • As a dissolved gas in the plasma. • A small percent of carbon dioxide is transported as a dissolved gas. • Some of the carbon dioxide is bound to hemoglobin, in the fo...

Glycolysis - and oxygen

By: HWC, Views: 7997

The first reactions involve a single 6-carbon glucose sugar undergoing phosphorylation using two ATP molecules and resulting in two 3-carbon compounds. • The rest of this pathway involves an oxidation reduction reaction, forming two reduced coenzymes, and generation of four ATP molecules. ...

Transferring genes into plants Animation

By: HWC, Views: 5098

Researchers extract DNA from an organism that has a trait they want to introduce into a plant. The genetic donor can be a bacterial cell, a plant cell. or even an animal cell. The desired gene will be transferred into a plasmid, a small circle of bacterial DNA. The gene is cut out of th...

Rh blood type and complications during pregnancy & Fertilization

By: HWC, Views: 5097

Complications can arise if an Rh- woman is impregnated by an Rh+ man. The fetus maybe Rh+. During childbirth, some of the fetal Rh+ cells may leak into the maternal bloodstream. The woman's immune system views the Rh+ as foreign and makes antibodies against it. If the woman becomes pr...

Sperm Formation Animation

By: Administrator, Views: 454

A man’s reproductive system is specifically designed to produce, store, and transport sperm. Unlike the female genitalia, the male reproductive organs are on both the interior and the exterior of the pelvic cavity. They include: the testes (testicles) the duct system: epididymis and vas def...

Nerve Type Animation (Part 1)

By: Administrator, Views: 330

Used to describe neuronal processes conducting impulses from one location to another. Nerve fibers: - Nerve fibers of the PNS are wrapped by protective membranes called sheaths. - Myelinated fibers have an inner sheath of myelin, a thick fatty substance, and an outer sheath or neurilemma compo...

Anatomy and Chemical Makeup of a Single Hair (Animation)

By: HWC, Views: 5936

The hair's outer cuticle surrounds hair cells filled with tough keratin macrofibrils. Each macrofibril consists of smaller microfibrils. A microfibril is made up of three keratin polypeptide chains. The chains are linked together by disulfide bonds. A hair consists of keratin chains held...