Heredity and Genetics Chapter 11

Inhereting Traits What are some traits that you can think of? Eye color, nose shape, hair color are all examples All organisms are a collection of traits passed down from its parents.

Inheriting Traits Heredity- The passing down of traits from parent to offspring.

Learned vs. Innate Learned traits are traits that are gained through observation over time. Talking and walking Innate traits are traits that one is born with. Crying, breathing, eating

Genetics Genes are found on chromosomes. These genes describe an organisms function. The different forms of a trait that a gene may carry are called alleles.

How does this happen? Offspring get one set of genes from the father and one from the mother. The parent gives half the genetic information through sex cells formed through meiosis.

Genetics Genetics is the study of how traits are inherited through the interactions of alleles.

Father of Genetics The study of genetics was founded by Gregor Mendel by studying how traits were passed down from generation to generation in pea plants. Mendel was the first to trace on trait through several generations. He was also the first to mathematically predict traits in a generations.

Mendel’s Genetics When Mendel crossed two pea plants he noticed the offspring always looked like one of the parents. He called the offspring hybrids because they received different genetic information from both parents.

Purebred Mendel noticed some plants always produced the same type of offspring. Tall plants always produced tall plants.

Dominate vs. Recessive Mendel used pollen from two different purebred (tall and short) to breed. This is called cross pollination. He found they only produced tall plants.

Dominant vs. Recessive Mendel called the trait that is shown the dominant trait. This is because it dominated the other. The trait that is hidden was called recessive.

Homozygous/Heterozygous An organism with two alleles that are the same is called homozygous. This can be homozygous recessive or dominant. An organism with two different alleles is called heterozygous.

Genotypes A genotype is the genetic make up of an organism. The way an organism looks or behaves is its phenotype.

Alleles Most cells in your body have two alleles for every trait. These alleles are located on the chromosomes.

Probability of Heredity Probability is used to predict the chance of something to happen. 0% probability that UK wins NCAA!

Punnett Squares A Punnett Square is a tool used to predict the probability of an offsprings genetics.

Punnett Squares In Punnett Squares, letters represent dominant and recessive traits.

Punnett Squares An upper case letter= dominant trait A lower case letter= recessive trait

How to use a Punnett Square