Mutations

7. Lesson Summary

Lesson Summary

• Mutations are caused by environmental factors known as mutagens. Types of mutagens include radiation, chemicals, and infectious agents.
• Germline mutations occur in gametes.
  
• Somatic mutations occur in other body cells.
  
• Chromosomal alterations are mutations that change chromosome structure.
  
• Point mutations change a single nucleotide.
  
• Frameshift mutations are additions or deletions of nucleotides that cause a shift in the reading frame.
• Mutations are essential for evolution to occur because they increase genetic variation and the potential for individuals to differ.
  
• The majority of mutations are neutral in their effects on the organisms in which they occur.
  
• Beneficial mutations may become more common through natural selection.
  
• Harmful mutations may cause genetic disorders or cancer.

CK-12 Foundation, Biology. http://creativecommons.org/licenses/by-nc-sa/3.0/