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DNA fingerprinting Animation

By: HWC, Views: 3591

DNA fingerprinting enables a scientist to compare the DNA from two biological samples, such as a blood stain and a suspect's blood. A restriction enzyme is added to the samples to be compared. The enzyme cuts the DNA into smaller fragments. The DNA fragments are placed on an electrophor...

Muscle cell structures - actin, myosin and titin filaments

By: HWC, Views: 6786

Once the muscle cell has been excited it will contract. • A muscle action potential will trigger the release Of Ca2+ ions into the sarcoplasm. • The Ca2+ ions bind to the regulatory proteins and trigger contraction. • Within skeletal muscle cells are structures that provide the ability...

What are the Parts of a Plant Cell?

By: HWC, Views: 5702

Every chloroplast in a plant cell is packed with stacks of flattened sacs called thylakoids. The thylakoid membranes contain chlorophyll, as well as most of the other components required for the light reactions of photosynthesis. The chlorophyll-containing structures within the membranes are c...

Frequency of stimulation and force (Recruitment of motor units and force)

By: HWC, Views: 7004

• Muscle tension depends on the frequency of stimulation. • Muscle twitch: First stimulus. • Wave summation: When a second stimulus excites a partially relaxed muscle, producing a stronger contraction. • Unfused tetanus: Successive stimulations at the same frequency, producing a se...

Neural regulation of mechanical digestion- CNS voluntary, ANS & ENS controlled involuntary movements

By: HWC, Views: 6589

• The gastrointestinal [GI] tract is basically a muscular tube that contains and processes food as it moves from the mouth to the anus. • Mechanical digestive functions consist of both voluntary and involuntary muscle contractions and relaxation including: • Chewing and swallowing food....

Body plan of euglena Animation

By: HWC, Views: 992

Euglenoids are single-celled organisms that live in lakes and ponds. A contractile vacuole pumps out the water that diffuses into the cell from its hypotonic surroundings. The body is covered by a translucent pellicle composed of flexible strips of a protein-rich material. Light passe...

Interpreting a cladogram Animation

By: HWC, Views: 295

Using a cladogram to determine relative relatedness and whether the lungfish is more closely related to a human or to a trout. To determine the relative relatedness, we begin by tracing the branches from the human and the lungfish to the point where they meet. We'll call this node 1. Now...

Condensation and Hydrolysis Animation

By: HWC, Views: 540

A condensation reaction joins two molecules together to form one larger molecule. An enzyme removes a hydroxyl group from one molecule and a hydrogen atom from another, then speeds the formation of a bond between the two molecules at their exposed sites. Typically the discarded atoms join t...

Photosynthesis overview Animation

By: HWC, Views: 406

Illustration of the interrelationships of the light-dependent and light-independent reactions of photosynthesis. The light-dependent reactions split water, and produce ATP and NADPH. Oxygen is a by-product of these reactions. ATP and NADPH, together with carbon dioxide, are reactants in ...