Final answer:
Genetic mutations are changes in the DNA sequence that occur in all organisms and can be affected by environmental factors. They do not happen as a response to an organism trying to adapt; instead mutations are random, but selection can influence their prevalence in a population.
Step-by-step explanation:
Concerning genetic mutation, the following statements are true:
- A mutation is a change in the nucleotide sequence of DNA of a cell.
- It occurs in all organisms.
- The rate of mutation may be changed due to environmental factors.
However, it is a misconception that mutations happen in an individual organism striving to adapt to a new challenge; rather, mutations are random events that may provide an organism with an advantage or disadvantage in certain environments, with selection pressures determining the frequency of the mutation in the population. Mutations can be caused by errors during DNA replication or by exposure to mutagens such as radiation or chemicals. Some mutations have no effect while others can have significant impacts on an organism's phenotype and even lead to genetic diseases.