Both parents must be carriers, which means they have the heterozygous gene (one uppercase letter & one lower case letter). They will still carry that mutated gene (because they have a lower case letter), and their offspring will have a 25% chance of getting a recessive disorder. The percentage is low but still possible.
The period you’ve described would be the G2 phase which is considered a “checkpoint” that determines whether or not a cell can enter the mitosis phase
Each one is made of one original strand and one new strand.<span>It bonds together the nucleotides in the new strand</span>
