GENETIC NOTES Heredity is the passing of traits

GENETIC NOTES

Heredity is the passing of traits from parents to offspring.

Offspring are the new organisms produced by one or more parents. (children, babies, young)

The study of heredity in biology is called genetics.

The Father of Genetics Gregor Mendel was an Austrian monk who studied mathematics and science but became a gardener in a monastery.

Mendel thought there might be a connection between the color of a pea plant flower and the type of seed the plant produced. He began to experiment with garden peas in 1856. Mendel made careful use of experimental design to study pea plants and had the first recorded study of how traits pass from one generation to the next.

What are some patterns of inheritance in humans? Some human traits are controlled by single genes with two alleles, and others by single genes with multiple alleles. Still other traits are controlled by many genes that act together

What traits are controlled by a single gene with two alleles? Widow’s peak Cleft chin Dimples These human traits have two distinctly different phenotypes and, or physical appearances

What are some traits controlled by a single gene with multiple alleles? Multiple alleles – three or more forms of a gene that code for a single trait Remember: a person carry only two of those alleles Human Blood

What are some traits controlled by many genes? Height – at least four genes control height in humans Skin/Hair color

What are sex-linked genes? Genes for human traits that are carried on the sex chromosomes (X or Y) Colorblindness (most common -cannot distinguish between green and red)

What numbers do you see? 5 45

Mutations A change in genetic information • Can occur randomly (naturally) • Or can be deliberately caused in the laboratory by scientists • Inherited • Not always harmful http: //www. accessexcellence. org/

What are two major causes of genetic disorders in humans? Some genetic disorders are caused by mutations in the DNA of genes. Other disorders are caused by changes in the overall structure or number of chromosomes

Natural Mutations These are not albinos; they have pigmented eyes. White Bengal Tiger

Selective Breeding The Cama is the result of breeding a Llama to a Camel The mule is the results of breeding a horse and a donkey

The Zebroid is the result of breeding a female Horse and a male Zebra. The Zedonk / Zonkey is the result of breeding a female Donkey and male Zebra.

Vocabulary to Know Alleles- traits- symbolized with upper and lower case letters Dominant alleles – cover up other traits example : Bb Recessive traits- trait seems disappear or hide example : bb Genotypes – genetic makeup Phenotypes – the way an organism looks or behaves as a result of it genotype