Genetics Part 1 You have your genes to thank – or blame for how you look • Genes are your body's instruction manual. • They affect the way you look, your health, and the way your body works. Heredity is the passing on of characteristics from one generation to the next. • It is the reason why offspring look like their parents. • The study of heredity is called genetics and scientists that study heredity are called geneticists. Genes and Inheritance • Your genes are unique – unless you have an identical twin. Genes and Inheritance • Half of your genes are from your mother • the other half are from your father, • who, in turn, received their genes from their parents, • and so on, right back to your earliest ancestors DOMINANT & RECESSIVE • Certain genes are dominant, and you only need one of the pair to give you its trait. • Dominant genes are represented as capital letters and recessive genes as lower-case letters. Some Human Traits Some Human Traits 6 Fingers and Toes Are Dominant Alleles • Are all the possible genes for a trait The Gene Locus • Is the location of a gene on the on the chromosome Genotype vs Phenotype • Genotype Is the actual genes that an • Phenotype individual has the physical for a trait expression of the genes Let’s check your understanding with………. A Game of X’s and O’s 1 2 4 7 3 5 8 6 9 Scoreboard 1 2 3 X 4 5 6 O 7 Click Here if X Wins Click Here if O Wins 8 9 1 What structure on chromosomes carry the instructions for a trait? 1 Home Genes 2 What is the passing of characteristics from one generation to the next? 2 Home Heredity 3 What is the study of heredity? 3 Home Genetics 4 True or False: You get all of your genes from your mother. 4 Home False 5 You must have two of these genes in order for it to be expressed. 5 Home Recessive 6 All the possible genes for a trait 6 Home Allele 7 The location of a gene on a chromosome 7 Home Locus 8 True or False: The color purple is an example of genotype 8 Home False 9 True or False: Dominant genes are represented by capital letters 9 Home True Adapted From Presentation © 2000 - All rights Reserved markedamon@hotmail.com