Mutations and Genetic Change. Section 14.1 Page. 319-324. What are mutations ?. Mutations are changes in the structure or amount of genetic material of an organism. Organisms whose DNA or chromosomes have mutations are called mutants. What causes mutations?.
Mutations and Genetic Change
Mutations are changes in the structure or amount of genetic material of an organism.
Organisms whose DNA or chromosomes have mutations are called mutants
Mutations occur as a result of:
Mutations as changes in DNA—when the wrong nucleotide may be paired or placed in a sequence during DNA replication
Point mutation is a change in a single base pair in DNA
Example: (When a letter is changed)
Insertion or Deletion is an insertion or deletion of one or more nucleotides in a sequence
THE DOG BIT THE CAT.
THE DOG BIT ETH ECA T. (Insertion) or
THE DOG BIT THC AT. (Deletion)
Mutations as changes in the results of gene
Missense mutation results when a codon is changed, the codon codes for a different amino acid
Example: AGC (codes for Serine) AGA (codes for Arginine)
Example: (When a letter is deleted)
Chromosomal Mutations—the process of meiosis creates the chance of mutations at the chromosomal level
Deletion occurs when a piece of chromosome is lost
Duplication occurs when a piece remains attached to its homologous chromosome after meiosis
Inversion occurs when a piece reattaches to its original chromosome in a different direction
Translocation occurs when a chromosome piece ends up in a completely different, nonhomologous chromosome
Gene Rearrangement occurs when an entire gene moves to a new location