Mutations are changes that occur in the DNA sequence of an organism. In single-celled organisms that reproduce asexually, the DNA is copied exactly during cell division, and the offspring inherits the same DNA sequence as the parent. Therefore, any mutations that occur are also inherited by the offspring.
However, in organisms that reproduce sexually, the genetic material from two different individuals is combined to produce offspring with a unique DNA sequence. In this case, mutations that occur in one parent may not necessarily be inherited by the offspring if they occur in a non-reproductive cell or if they do not occur in the gametes (sex cells) that are used to produce the offspring. Additionally, some mutations may be lethal or cause a decreased fitness, so they may not be passed down to the next generation. Therefore, mutations are not always inherited in organisms that reproduce sexually.