Genetic Mutations

What Are Mutations? Changes in the nucleotide sequence of DNA May occur in body cells and are not passed to offspring May occur in gametes (eggs & sperm) and be passed to offspring

Are Mutations Helpful or Harmful? Mutations happen regularly and often neutral Many mutations are naturally repaired by enzymes Causes of mutations: Natural Chemicals Radiation Other environmental factors

Are Mutations Helpful or Harmful? Some mutations are harmful and can cause: Cancer Birth defects Physical impairments Other life altering conditions Some mutations may improve an organism’s survival This is know as evolution

Chromosome Mutations and Gene Mutations Types of Mutations Chromosome Mutations and Gene Mutations

Chromosome Mutations May Involve: Changing the structure of a chromosome The loss or gain of part of a chromosome

Types of Chromosome Mutations Five types exist: Deletion Inversion Translocation Nondisjunction Duplication

Due to breakage, a piece of a chromosome is lost Deletion Due to breakage, a piece of a chromosome is lost

Inversion Chromosome segment breaks off Segment flips around backwards Segment reattaches

Occurs when a gene sequence is repeated Duplication Occurs when a gene sequence is repeated

Translocation Involves two chromosomes that not homologous Part of one chromosome is transferred to another chromosomes

Nondisjunction Caused by a failure of chromosomes to separate during meiosis As a result, the gamete will have too many or too few chromosomes

Gene Mutations

What are Gene Mutations? Change in the nucleotide sequence of a gene May only involve a single nucleotide May be due to copying errors, chemicals, viruses, etc.

Types of Gene Mutations Include: Point Mutations Substitutions Insertions Deletions Frameshift

Point Mutation What is it? Example: Change of a single nucleotide Includes the deletion, insertion, or substitution of ONE nucleotide in a gene Sickle Cell disease is the result of one nucleotide substitution Occurs in the hemoglobin gene

Frameshift Mutation Inserting or deleting one or more nucleotides Changes the “reading frame” like changing a sentence Causes proteins to be built incorrectly

Food inc Class Discussion

Discussion See teacher for details

Modern Genetics

Objectives Describe ways of producing organisms with desired traits State the goal of the human genome project

Selective Breeding Definition: The process of selecting organisms with desired traits to be the parents of the next generation This process has been used for hundreds of years Two Types: Inbreeding- crossing two individuals that have similar characteristics Hybridization- crossing two genetically different individuals

Cloning Cloning- a technique used to produce offspring with desired traits (identical to the traits of another organism) Clone- an organism that has identical gene as the one from which it was produced WATCH - BrainPop: Dolly the Sheep

Genetic Engineering Genetic engineering- genes from one organism are transferred into the DNA of another Examples …. Gene therapy- use of genetic engineering to correct genetic disorders. Concerns…

The Human Genome Project Genome- all of the DNA in one cell of an organism Goal of the Human Genome Project: Identify the sequence of every gene in the human genome Interesting Facts: The DNA of humans consists of at least 30,000 genes Each gene has about 3,000 bases (A, T, G, C) Other Uses: DNA Fingerprinting Technology used in the Human Genome Project can be used to identify people and show whether people are related