Gel electrophoresis is a method of genetic analysis which involves seperating segments of DNA based on their size and charge.
It involves cutting DNA with various enzymes, then placing the DNA in an agarose gel. An electrical current is then run through the gel. Because DNA is a polar molecule the DNA segments will travel through the agarose cell as the current is applied. Larger fragments will travel shorter distances than shorter fragments. Two plates with 2 different DNA samples will be conducted and the orientation of the DNA strands will be used to make an analysis by comparing the 2 plates.
1) Are they reliable?
2) Are they relevant?
3) Are they recent?
4) Are they sound resources?
5) Are they a primary source?
6) Are they a secondary source?
<span>Some 120 prescription drugs sold worldwide today are derived directly from rainforest plants. And according to the U.S. National Cancer Institute, more than two-thirds of all medicines found to have cancer-fighting properties come from rainforest plants. Examples abound. Ingredients obtained and synthesized from a now-extinct periwinkle plant found only in Madagascar (until deforestation wiped it out) have increased the chances of survival for children with leukemia from 20 percent to 80 percent.</span>
Answer:
<u><em>All of the above.</em></u>
Explanation:
1. Their watertight skin minimizes moistures loss: <em>Reptiles have a reputation that they are “slimy” when we touch and hold them; however, they have dry skin, which has even fewer glands than mammals or amphibians. The main special feature of their skin is that the epidermis is heavily keratinized with a layer, which also prevents water loss.</em>
2. Amphibians must lay eggs in water or in moist soil to reduce moisture loss: <em>Because amphibian eggs don't have an amnion, the eggs would dry out if they were laid on the land, so amphibians lay their eggs in water.</em>
3. Reptile egg shells are harder than amphibians' eggs: <em>Reptile eggs are coated with a leathery or brittle coating, and the animals that hatch from them are miniature versions of the full-sized animal parent. In contrast, amphibian eggs are transparent and jelly-like. The animals that hatch from them still must go through metamorphosis.</em>
<u><em>Hope this helps you have a better understanding:) !!</em></u>
