The study of genes and the inheritance of traits Genetics The study of genes and the inheritance of traits

What is Genetics? Genetics is the science of genes and how traits are passed on from one generation to the next.

Everything Has DNA! DNA is an amazing chemical present in every cell. It contains all the information cells need to make a fish a fish, or you YOU. DNA influences many individual traits, such as whether you are a boy or a girl and whether you are tall or short.

DNA is made up of Genes Where do traits, such as eye color and shape, come from? Why do you look more like your relatives than other people? The parts of your cells that determine these traits are called genes

DNA is made up of Genes Genes come in pairs. You get half of your genes from your mother, and the other half from your father.

Human Genes Today, scientists are studying human genes to learn about traits and diseases. There are so many genes in humans — at least 30,000 of them — that it will take a long time to study every one in detail and find out what it does.

Gregor Mendel Gregor Mendel was the “Father of Modern Genetics” Personal history Austrian monk Teacher of high school natural science- love of evolution, nature, meteorology “for the fun of it”: crossed peas and mice- saw inheritance patterns Pea plants- a formal test

Characteristics These are features you exhibit physically ( your looks) Example: Eye color - green

Traits The different versions of a characteristic Example: blue, green, and brown eyes

Inheritance Occurs when traits are passed down from parent to child.

Genes Bits of genetic information passed down from parent to child. Made of chemicals called DNA.

Genetic Diseases Can be passed on through genes from a parent to the child. Example : Marfan Syndrome (Individual is tall, has long arms and legs, may have arthritis and heart problems) Ex: Abraham Lincoln

Reproduction Sexual – Sperm fertilizes an egg to produce offspring Asexual – occurs when 1 organism copies itself to produce offspring

Fertilization Occurs when a sperm unites with an egg

Offspring Another name for the children of a male and female parent

Mutation Occurs when genes make a mistake mixing and produce new or different traits in the offspring.

Genotype B is dominant for black fur, b is recessive for brown fur A combination of alleles inherited from both parents Example: BB, Bb, or bb B is dominant for black fur, b is recessive for brown fur BB = black fur Bb = black fur bb = brown fur bb BB Bb 17

Phenotype They are the traits expressed by reading the genotype. Black, brown or Golden 18

Alleles TT – is dominant Tt or tT – is dominant tt - is recessive “T” – is considered a dominant allele “t” – is considered a recessive allele The dominant allele is stronger than the recessive allele and is the characteristic that is expressed. TT – is dominant Tt or tT – is dominant tt - is recessive

Allele types Homozygous Both alleles are identical tt, TT Heterozygous Both alleles are different Tt, Dd