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Modern Genetics. Human inheritance. Some traits are formed from single genes (2 alleles) Some are formed from multiple genes (multiple alleles) Example: blood type. Blood types. Types: A, B, AB, O 3 alleles control the blood type A & B are co dominant O is recessive. SexChromosomes.
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Human inheritance • Some traits are formed from single genes (2 alleles) • Some are formed from multiple genes (multiple alleles) • Example: blood type
Blood types • Types: A, B, AB, O • 3 alleles control the blood type • A & B are co dominant • O is recessive
SexChromosomes • Carry genes that determine if a person is male or female • Each parent offers 2 alleles • Male X, Y • Female X, X • Alleles on the X and Y chromosome are not the same
Sex Linked Genes • Genes carried on the sex chromosomes • A female has 2 X chromosomes: if one x has a dominant gene and the other has a recessive, the dominant trait will show • In a male, there isn't corresponding alleles. If the X chromosome has a recessive trait, and there is no corresponding allele on the Y chromosome, then the recessive trait will show. • Therefore, males have a higher tendency to show recessive sex linked traits.
Carriers • A heterozygous person • Because they have the dominant allele, the recessive trait doesn't show, but they can still pass it along to offspring
Genetic Disorders • Def: an abnormal condition inherited through chromosomes • Some are caused by mutations • Some caused by an change in chromosome number • Cystic fibrosis • Sickle cell • Hemophilia • Down syndrome
Pedigree • Chart that tracks which family members have a certain trait
Managing Disorders • Karyotype: picture of the chromosomes in a cell--can determine if a mutation or extra chromosome is present • Genetic counseling: to help coping with disorders • Therapy: to assist with disorders
Modern Genetics Selective Breeding: is the process of selecting and breeding parent organisms to pass on particular traits to the offspring. Examples: Horses, pigs, corn, dogs Question: What do you thing the animal to the left is? It has been selectively bred.
Modern Genetics Cross Breeding: A cross between two pure breed parents creating a hybrid. Killer Bees: a cross between Brazilian bees with African bees to create a bee that would produce more honey.
Modern Genetics Genetic Engineering: is the process in which a sequence of DNA from an organism is first isolated, then inserted into the DNA of another organism, changing that organism’s DNA. Example: Taking genes from microorganism and inserting them into plants to produce a natural insect killing chemical. Inserting a bioluminescent gene into bacteria to make it glow.
Modern Genetics Genetic Engineering vs. Organic Most of you have eaten genetic engineered/ modified foods. Many plants have bacterial genes that make them more resistant to insects. How many of you have eaten fruits without seeds? Picture: Here is a tobacco plant that glows.
Modern Genetics Cloning: is a technique that uses technology to make copies. It can be applied to a segment of DNA or the whole organism. Examples: Bacteria: create human insulin which is used to help people with diabetes. A sheep named Dolly. (Nucleus Transfer)
Modern Genetics Cloning a Gene
Modern Genetics Genome: is all the genetic material in an organism.
Modern Genetics So why clone? • Medicine • Reviving endangered or extinct animals: Jurassic Park! • Reproducing a deceased pet • Cloning humans
Modern Genetics DNA Identification: The use of DNA to identify a person. DNA Fingerprinting: Chart representing repeating base pairs Example: Used in crime solving A fun case at NOVA. DNA Evidence Video
Modern Genetics What are Some Issues to Cloning? The Good vs. Bad What are the ethical issues?
Modern Genetics There are genetically engineered salmon that grow faster. They are breed in captivity, near rivers and stream. What might happen if they escape?
Modern Genetics Should we label genetically modified foods? Many companies already label food and products that have been genetically altered.