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Meselson & Stahl grew E. coli cells in a dense N15 nitrogen medium, then transferred to a lighter N14 nitrogen medium. Describe the observations of their experiment (until the third generation) and use it to explain the mechanism of DNA replication.

Observations: - After each generation, the amount of DNA will be doubled during the S phase of interphase- At the start, all DNA will be labelled N 15 - In the generation 1, all DNA will be labelled N 14 N 1...
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Outline how neurons generate a resting potential

Neurons use a sodium potassium pump to maintain a resting potential in the body. Inside a cell normally, there are more sodium in the cell and fewer potassium outside the cell, and hence there is a negative ...
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Where in the nephron does osmoregulation occur?

In the Loop of Henle. Here a salt gradient is established as the loop of Henle is permeable to both water and salts such as sodium.
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Describe the Process of DNA Replication

During DNA Replication, the existing molecule gets replicated, resulting in two semi-conservative DNA molecules. The enzyme helicase unwinds and unzips the double helix of the DNA, while topoisomerase moves ...
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Describe the structure of proteins

-Primary structure is the number and sequence of amino acids in a polypeptide.-The secondary structure of a polypeptide is the formation of alpha helices and beta- pleated sheets stabilised by hydrogen bondi...
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