Final answer:
True, mutations can have negative, positive, or neutral effects on an organism. Neutral mutations do not affect protein function, deleterious mutations reduce fitness, and beneficial mutations can increase an organism's ability to survive and reproduce.
Step-by-step explanation:
True, mutations can be negative, positive, or result in no observable changes. This is because mutations are essentially changes in an organism's DNA and can vary widely in their effects. A mutation may have no effect and be considered neutral, such as silent mutations that do not change the amino acids in proteins they encode. On the other hand, some mutations may be deleterious and reduce an organism's fitness, thereby lowering its likelihood of survival and reproduction. Conversely, there are also beneficial mutations which can increase an organism's fitness and help it better adapt to environmental changes. An example of a beneficial mutation is the CCR5-Δ32 mutation, which confers resistance to HIV, while an example of a harmful mutation could be those causing genetic disorders like cystic fibrosis.