The mutation that could be passed on to future generations is option C, in which a sperm cell has an extra nucleotide on chromosome 23 that was not in the parent cell.
Mutations are changes to the genetic material of a cell that can potentially be passed on to future generations. These changes can occur in the DNA of an organism's cells, as well as in the RNA molecules that are transcribed from DNA.
In option A, a nerve cell has an adenine substituted for a guanine base on one of its chromosomes. This is an example of a point mutation, in which a single nucleotide is changed within a strand of DNA. However, this mutation is not likely to be passed on to future generations, as it occurred in a nerve cell rather than in a reproductive cell.
In option B, a strand of mRNA has a mistake in it that was not in the original DNA strand. This is an example of a transcription error, in which a mistake is made during the process of transcribing DNA into RNA. However, this mutation is also not likely to be passed on to future generations, as it occurred in an RNA molecule rather than in DNA.
In option C, a sperm cell has an extra nucleotide on chromosome 23 that was not in the parent cell. This is an example of a chromosomal mutation, in which a change occurs in the structure or number of chromosomes in a cell. Because this mutation occurred in a sperm cell, it has the potential to be passed on to future generations through sexual reproduction.
In option D, a strand of replicated DNA in a liver cell has a mistake on it that wasn’t in the original DNA strand. This is an example of a replication error, in which a mistake is made during the process of copying DNA strands. However, like options A and B, this mutation is not likely to be passed on to future generations