Copying and Mutations

Each time a cell, such as a skin cell, is replaced, ins chromosomes are copied. The DNA unwinds and unzips down the middle.

Ribonucleic acid (RNA) is generated to match each half-strand, and then used as a template on which new DNA forms from proteins within the cell.

The copying process is so accurate that there may be only one mistake, or mutation, in one gene, for every million copies: this would be like retyping these two pages five million times before typing one wrong letter.

These rare mistakes can create cancers, and may contribute to aging. Information is passed down the generations in a different way.

Egg and sperm cells contain only 19 chromosomes, each one half of a pair. At conception, the 19 chromosomes in the egg unite with the 19 in the sperm, creating a new, unique set of 19 pairs.

Each kitten inherits half of its genetic material from each parent. When chromosomes  pair up, the genes for each characteristic also pair up, side by side. Mistakes, or mutations, sometimes occur in egg or sperm cells, creating new traits.