Mutations Chapter 11, Section 6

What are Mutations? MUTATIONS are changes in the nucleotide sequence of DNA that are INHERITABLE. MUTATIONS are changes in the nucleotide sequence of DNA that are INHERITABLE. Changes can effect a single gene (GENE MUTATION) Changes can effect a single gene (GENE MUTATION) Changes can effect the number or structure of the chromosome (CHROMOSOMAL MUTATION) Changes can effect the number or structure of the chromosome (CHROMOSOMAL MUTATION)

GENE MUTATIONS POINT MUTATIONS POINT MUTATIONS Result of one nucleotide being substituted for another nucleotide in a DNA sequence Can change amino acid FRAMESHIFT MUTATIONS FRAMESHIFT MUTATIONS Result of a nucleotide being deleted or inserted into the DNA sequence Will change the remaining sequence of amino acids

Chromosomal Mutations Chromosomal mutations cause more variation than gene mutations Chromosomal mutations cause more variation than gene mutations Not all mutations are harmful!! Mutations are the ultimate source of genetic diversity in the living world! Not all mutations are harmful!! Mutations are the ultimate source of genetic diversity in the living world!

What Causes Mutations? They can be random mistakes in the replicating of DNA or chromosome crossovers in meiosis They can be random mistakes in the replicating of DNA or chromosome crossovers in meiosis Physical and chemical agents called MUTAGENS can also cause mutations Physical and chemical agents called MUTAGENS can also cause mutations EX: Physical = high energy radiation Chemical = chemicals that cause incorrect base-pairing Chemical = chemicals that cause incorrect base-pairing

Biotechnology and the Frontiers of Genetics Chapter 13

BIOTECHNOLOGY: Using Organisms to Perform Practical Tasks for Humans In the past… Breeders use selective breeding techniques to pass on desired characteristics Breeders use selective breeding techniques to pass on desired characteristics Hybridization: offspring are a blend of parents Hybridization: offspring are a blend of parents Inbreeding: offspring similar to parents Inbreeding: offspring similar to parents (higher rate of genetic defects)

Today… Scientists manipulate the living world on a molecular level to benefit human society Scientists manipulate the living world on a molecular level to benefit human society Use Recombinant DNA Technology (combines genes from different sources) Use Recombinant DNA Technology (combines genes from different sources) The DNA “code of life” is read and interpreted the same in all living things!! The DNA “code of life” is read and interpreted the same in all living things!!

Polyploidy Occurs when chromosomes fail to separate during meiosis and an organism inherits an entire extra set of chromosomes Occurs when chromosomes fail to separate during meiosis and an organism inherits an entire extra set of chromosomes 3N = triploid 4N = tetraploid Benefits: Makes plants taller and stronger; good for bananas and citrus fruits Benefits: Makes plants taller and stronger; good for bananas and citrus fruits Risks: Fatal in animals Risks: Fatal in animals

Genetically Modified Organisms (GMO’s) An organism with one or more genes acquired by artificial means An organism with one or more genes acquired by artificial means A TRANSGENIC has DNA from another species included A TRANSGENIC has DNA from another species included Benefits: Insulin producing bacteria, herbicide resistant crops, leaner meat, etc. Benefits: Insulin producing bacteria, herbicide resistant crops, leaner meat, etc. Risks: Food allergies, other negative health effects; introduced species or “superweeds” Risks: Food allergies, other negative health effects; introduced species or “superweeds”

Animal Cloning Benefits: Faster mass production of animals with desired characteristics; Reproduction of a GM animal Benefits: Faster mass production of animals with desired characteristics; Reproduction of a GM animal Risks: Loss of life; Ethical concerns, expensive Risks: Loss of life; Ethical concerns, expensive

DNA Fingerprinting Gel Electrophoresis is the technique used to create DNA fingerprints Gel Electrophoresis is the technique used to create DNA fingerprints Can compare DNA from multiple subjects to solve a crime, determine paternity, etc. Can compare DNA from multiple subjects to solve a crime, determine paternity, etc.

The Complexity of Genetic Expression in Eukaryotes From the time the egg is fertilized, gene expression is regulated as the cell divides into a multicellular embryo. 7 days after fertilization, a human embryo is mostly a hollow ball and about 100 embryonic stem cells. Adult bone marrow also contains stem cells. Stems cells have the potential to differentiate into any type of cell, therefore the potential use in the medical field is bountiful. The ethics of embryonic stem cell use continues to be debated.

Homeotic Genes Genes that control the direct development of body parts in specific locations Research helps use understand the diversity and relatedness of organisms