H1 Gene Mutation slides

Understand the basis for genetic diseases Sickle-cell anemia Chronic, inherited anemia in which RBCs sickle & clog capillariesBreast cancer 5% of all cases Amyotrophic Lateral Sclerosis (ALS) Late-onset lethal degenerative nerve disease

• Central Dogma & the Genetic Code What happens when DNA is altered?

• 2(d) Explain what is meant by the terms gene mutation and chromosomal aberration. For gene mutation, knowledge of how substitution, addition and deletion could change the amino acid sequence (including frameshift) is required. 2(e) Explain how gene mutations can result in diseases (including sickle cell anaemia). PG 37

Definition: • Change in the sequence, amount or structure of the DNA of an organism. Pg.1PG 37 Gene Chromosome

• There are several ways to classify the types of mutations, by: Pg.1 Not in notes Cause of mutation Type of cell the mutation occurred in Nature of mutation

Pg.1PG 37 Somatic Germline Occurred in somatic cells - cells other than germ line cells. Occurred in the specialized cells that give rise to gametes Spermatogonia / oogonia

Pg.1 Somatic Germline Mutations are passed on to the daughter cells after mitosis, i.e. remains in same organism. A gamete with the mutation passes it on to the new offspring at fertilization PG 37

Germ-line mutations Not in notes Somatic mutations

Pg.1 Cause of mutation Type of cell the mutation occurred in Nature of mutation PG 37

Pg.1 Spontaneous Induced Happen naturally. No specific agents are associated. e.g. errors during DNA replication, recombination or repair e.g. mutagens DNA Pol’s error rateof 1/100,000,000 bp = ~0.6 to 1 mutation per replication of human genome PG 37