Unit 5 Genetics study guide concept 3

2. What is a mutation? Are mutations always harmful? Explain.

A mutation is a change in DNA - can happen in any cell in the body. No, Mutations can be neutral, beneficial, or harmful. An example of good mutation is Camouflage. Some mutations can lead to cancer (uncontrolled cell growth which is a bad mutation).

3. What causes mutations? What are external causes of mutations?

DNA replication (Internal) - Mistake during base pairing and/or Spontaneous (it just happens) Mutagens - Factors that cause mutations (External) Radiation (ex. X-Rays, UV light) and Chemicals (asbestos, benzene, formaldehyde (found in cigarette smoke))

5. Explain the difference between a gene mutation and a chromosomal mutation. Why do chromosomal mutations tend to have greater impact on organisms than gene mutations?

Gene Mutations affect only one gene and it typically changes in one or a few nucleotides. Chromosomal mutation affects numerous genes and changes structure of the chromosomes. Chromosomal mutations tend to have greater impact on organisms because it affects greater number of genes.

4. Explain the difference between mutations in sex cells and those in somatic cells

Mutations in sex cells can be passed to offspring (or children) whereas mutations in somatic cells only affects the individuals and will not be passed to the offspring.