Basics of Genetics

Introduction Why are your eyes the color they are? Why is your hair the color that they are? Do any of these traits have something in common with your parents?

Introduction Things like hair color are passed from parents to their offspring The parents give offspring DNA that expresses proteins in their body By giving their offspring segments of their DNA, parents give certain genes to their children Heredity is the passing of traits from one generation to the next

Introduction Genetics is the field of biology dedicated to studying how information is passed from parent to offspring Genetics is one of the hottest fields in science right now

Gregor Mendel In 1851 a monk named Gregor Mendel entered the University of Vienna to study science After learning about math and science he returned to his monastery and resumed his job as a high school teacher and gardener

Gregor Mendel While he was working in his garden, Mendel started to notice that there were patterns in some of the plants that he was planting He thought that there might be a scientific reason for the patterns that he was observing

Gregor Mendel Mendel decided to start studying the patterns in his pea plants He decided to study certain traits in pea plants Traits are distinguishing feature of an organism Remember, Mendel had no knowledge of DNA

Mendel’s Experiments Mendel’s experiments changed modern biology as we know it Since they did it is important to understand what he did and what results he obtained … even if they were fraudulent

Mendel’s Experiments Mendel started by stopping the pea plants ability to self fertilize Then he opened individual flowers and cross fertilized them with other individual flowers Once he did he documented the resulting crosses and what offspring came from them

Mendel’s Experiments Mendel studied seven different types of characteristics Flower Color Flower Position Seed Color Seed Shape Pod Shape Pod Color Stem Length He called the first generation of each of these plants the “P” of parental generation

Mendel’s Experiments He called the next generation of plants the “F1” generation of plants P  F1 The generation after F1 was called the F2 generation P  F1  F2 What do you think the next generation was called?

Mendel’s Experiment What happened when Mendel crossed his true breeding P generation? The F1 generation showed traits of only one of the P generation it was crossed with When purple flowers were crossed with white flowers, only purple flowers were observed

Dominance This was because some of the traits are dominant over others This means that when a trait is expressed over a second trait, it is considered dominant When one trait is not expressed over another it is considered recessive

Dominance The term given to a possible trait based on genetics is allele Each trait has the same number of alleles from the mother and the father This means alleles can be dominant or recessive

Dominance Round Green A round seed is crossed with a wrinkled seed The F1 generation is round Which allele is dominant? A green pod is crossed with a yellow pod The F1 generation has green pods Round Green

Video https://www.youtube.com/watch?v=GTiOETaZg4w