Answer:
Columns in going side to side
Explanation:
Actually, the answer would be 4. Gasoline. Think about it: once you use gasoline, can you use it again? All the other answers can be used again (wind will never go away, trees can be recycled, corn can be composted) but gasoline can't be used twice.
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Answer:
It can help us determine the DNA's approximate sizes and charges.
Explanation:
Gel electrophoresis is a technique used to separate DNA fragments (or other macromolecules, such as RNA and proteins) based on their size and charge. Electrophoresis involves running a current through a gel containing the molecules of interest. Based on their size and charge, the molecules will travel through the gel in different directions or at different speeds, allowing them to be separated from one another.
Once the fragments have been separated, we can examine the gel and see what sizes of bands are found on it. When a gel is stained with a DNA-binding dye and placed under UV light, the DNA fragments will glow, allowing us to see the DNA present at different locations along the length of the gel.
A well-defined “line” of DNA on a gel is called a band. Each band contains a large number of DNA fragments of the same size that have all traveled as a group to the same position. A single DNA fragment (or even a small group of DNA fragments) would not be visible by itself on a gel.
By comparing the bands in a sample to the DNA ladder, their approximate sizes can be determined.
The yolk of an egg is the food and nutrient source for the chick as it grows, humans do not need this because they get all of the nutrients they need for development from the mother through the umbilical cord.