mutations learning targets: describe different gene mutations
TRANSCRIPT
Overview
• Cells occasionally make mistakes in copying their own DNA, by inserting the wrong base or skipping a base all together.
• Mutations - Changes in the genetic material
Kinds of Mutations
• Gene Mutations – Mutations that produce changes in a single gene.
• Chromosomal Mutations – Produce changes in whole chromosomes.
Gene Mutations
• Point Mutation– Gene mutations involving changes in one or a few
nucleotides.– Include substitutions (one base changed to another)– Include insertions and deletions (base inserted or
removed from the DNA sequence)
• Frameshift Mutation– Gene mutations that shift the “reading frame” of a
genetic message.
Chromosomal Mutations
• Changes in the number or structure of chromosomes.– May change the locations of genes on chromosomes or the
number of copies of some genes
• Four types:– Deletion – Involves the loss of all or part of a chromosome.– Duplication – Produces extra copies of chromosome parts.– Inversion – reverse the direction of parts of a chromosomes.– Translocation – part of a chromosome breaks off and
attaches to another.
Genetic Disorders
– Hemophilia, – Sickle cell anemia, – Down’s syndrome, – Turner’s Syndrome,– Williams Syndrome,– Tay-Sachs disease, – Cystic fibrosis, – Color blindness and – Phenylketomuria (PKU).