Mutations and Genetic Variation
Changes in DNA
What mutations are
Mutations are changes in DNA sequence. They can happen when DNA is copied, or because of environmental factors such as radiation or certain chemicals.
Not all mutations are bad
Some mutations have no noticeable effect, some are harmful, and a few may be beneficial in a particular environment.
Variation and evolution
Mutations are one major source of genetic variation, which is the raw material for evolution.
Types of mutation effects
| Effect | Meaning |
|---|---|
| Neutral | No clear effect on the organism |
| Harmful | Reduces function or health |
| Beneficial | Improves survival or reproduction in a context |
What is a mutation?
A mutation is any change in the DNA code.
Correct answer: A change in DNA sequence
Can mutations ever be helpful?
Some mutations can increase survival or reproduction in certain environments.
Correct answer: Yes
Which is a major source of genetic variation?
Mutations create new DNA differences that can be passed on.
Correct answer: Mutations
Why is genetic variation important?
Variation allows natural selection to act and populations to change over time.
Correct answer: It gives populations differences that can help them adapt