Genetics - study of heredity Gregor Mendel is the first UNIT : Genetics What are the genetics vocabulary words which explain patterns of inheritance?   Heredity – passing of characteristics (traits)from parents to offspring Genetics - study of heredity Gregor Mendel is the first scientist to succeed in predicting how traits are passed on from one generation to the next

Genetics - Mendel worked with pea plants and studied only one trait at a time.

Genetics He came up with the following laws: Law of Segregation (separation) states that gene pairs separate when gametes are formed, so each gamete (sex cell) has only one allele of each pair

Genetics He came up with the following laws: Law of Independent Assortment states that different pairs of genes separate independently of each other when gametes are formed.

Important Genetics Vocabulary!!! Allele – different forms of a trait (remember: genes are found on chromosomes and code for specific traits   Ex: Trait: type of earlobe in humans Alleles: free or attached earlobes Attached is recessive!= e Free is dominant!=E

Important Genetics Vocabulary!!! Ex: Trait: hair color in humans Alleles: brown, blonde, red, black, etc…

Genetics Vocabulary - Alleles are represented by letters when you’re predicting the probability of traits to be passed down to your offspring. B=brown eyes b=blue eyes  

Genetics Vocabulary Dominant – allele that is visible - represented by a capital letter B=Brown eyes Recessive – allele that is “hidden”; it is “masked” by the dominant allele represented by a lowercase letter b=Blue eyes

Genetics Vocabulary Homozygous - 2 identical or same alleles for a trait a.k.a. Pure or purebred BB=homozygous dominant bb=homozygous recessive Heterozygous - 2 different alleles for a trait a.k.a. hybrid Bb=heterozygous

Genetics Vocabulary Phenotype – the physical appearance of an organism - what the organism looks like - represented by words/descriptions Ex. I have BLUE eyes! Genotype – the genes that an organism has - the genetic makeup –what genes make up the organism represented by letters Ex. I have the genes=bb