if there are at least 4 risers (steps) in the stairway, standard railings or handrails depending on the width and type of stairway. If the stairway is less than 44 inches wide and is enclosed on both sides, only one handrail is required, and if one side is open, only a railing on the open side is required. If both sides are open, standard railings are required on both sides. A standard railing for stairways would be between 30 and 34 inches above the forward edge of each riser.
If the stairway is between 44 and 88 inches in width, a handrail is required on each enclosed side and a standard railing is required on each open side. Any stairway over 88 inches wide must also have an intermediate railing halfway across its width. A winding stairway must also have a handrail offset for any portion of the risers with less than 6 inches depth.
An insertion changes the DNA sequence by adding one or more nucleotides to the gene.
Explanation:
As a result, the protein made from the gene may not function properly. A deletion changes the DNA sequence by removing at leats one nucleotide in a gene.??
