Genetics Notes

How does this happen?

Heredity The passage of genetic instructions from one generation to the next generation Traits are passed from parents to offspring through genetic material

Genetic Material: In the Nucleus DNA Genes Chromosomes Genetic material is located in the nucleus of each cell!!!

DNA Deoxyribonucleic Acid DNA has a double helix shape (twisted ladder) DNA is divided into segments called genes

Genes and Chromosomes Gene: A segment of DNA that codes for a specific trait Each of your cells has 46 strands of DNA inside (in the nucleus) Each DNA strand is wound up tightly around itself and is called a chromosome Replicated Chromosome

Karyotype: picture of all of the chromosomes in the nucleus of a cell

DNA, Genes, and Chromosomes

Traits Inherited traits: physical characteristics that are passed on from parent to child through DNA An organism can only pass its DNA to its children...nothing else! This means that an organism can only pass on traits that they are born with! Examples: eye color, height, gender, ear lobe shape, skin color, baldness, etc.

Traits Acquired traits: changes to physical characteristics that occur after conception/birth due to the environment Examples: broken bones, tattoos, haircuts, weight, bacterial/viral diseases, good grades, athletic achievements, etc. Acquired characteristics CANNOT be passed on from parents to offspring!

Environmental Influence Inherited traits are sometimes influenced or changed by the environment (these changes are NOT inherited/passed on) Example: height is affected by diet Example: muscle strength is affect by exercise

Inherited Traits and Genetic Material Inherited traits are governed in the genetic material found in genes, within chromosomes in the nucleus