The effect differs. It could produce a different amino acid in the sequence because the corresponding codon has changed. It could also prevent the production of the originally intended sequence by changing one of the amino acids of a "start" codon (aka AUG) or extend the protein's sequence by modifying a "stop" codon (UAA, UAG, UGA or UGG), producing a new protein that might be useless or have different effects on the cell.
Crossing over occurs but on in meiosis 1
Explanation:
The cell must be lysed (broken open) to release the nucleus. the nucleus (if present) must also be open to release the DNA. at that point the DNA must be protected from enzymes that will degrade it, causing shearing. [[ once the DNA is released, it must then be precipitated in alcohol...]
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