True or False: If a mutation occurs in a normal body, somatic, cell of an organism,
that mutation will be passed on to that organism’s offspring.
This question asks us about mutations that occur in somatic cells of an organism. You might recall that a mutation refers to a change in the DNA sequence. Mutations can occur in a single nucleotide of a DNA sequence or can occur over a
larger area and affect chromosomes. Mutations can be separated into two categories based on the type of cells they affect
and how they occur.
Some mutations can occur due to exposure to harmful environmental substances or
conditions throughout an organism’s lifetime. These are called induced, or acquired, mutations. Some examples include UV radiation from the Sun, certain chemicals, or
carcinogens. This is why smoking causes higher instances of lung cancer. The chemicals in cigarette smoke are carcinogens because they cause mutations to the
cells that are exposed. Induced mutations will only affect cells that come into contact with the harmful
environmental substance. These cells are usually somatic, or body, cells.
In contrast, spontaneous mutations occur due to errors in meiosis. You’ll recall that meiosis is a special type of cell division that produces gametes,
or our sex cells. As a result, spontaneous mutations occur mostly in gametes.
Because spontaneous mutations occur mostly in gametes, the resulting embryo will
inherit the mutation and this mutation will be passed on to the cells of the
organism as it develops. On the other hand, induced mutations will only exist in the body cells that were
exposed to the environmental substance or condition that caused the mutation. So these will not be passed on to the offspring.
Therefore, the statement “if a mutation occurs in a normal body, somatic, cell of an
organism, that mutation will be passed on to the organism’s offspring” is false.