Genetics Who are you and why are you the way you are? There are some traits that are hard to figure out like how your hair color came to be, or height. However, Some things are controlled by one gene. They are easy to see !

Single Gene Traits On a piece of paper, copy this chart type √ you Class Average Earlobes Free   Attached Dimples Absent Present Chin Cleft No Cleft Hair Line Straight Widows peak Finger Hair Thumb Hitchhiker's PTC Taste Non-taste Hand Clasping Right over left Left over right Color Blind See Red/ Green See no difference Handed left handed right handed Tongue Rolling Roll Non-rolling

Earlobes Dimples Chin (Cleft) Hairline Finger hair PTC Tasting Hand clasping Thumb Color Blind Handedness Tongue Rolling

Fill out the chart for you, then we will figure out the class averages together. Questions: For each of the traits, which would be the “dominant” trait from your data? (use class info) How can you use this to determine a possibility of what traits your children would show? Take the chart home and survey your Mother and Father, and even grandparents (if you can) and bring back results.

Genetics Def: the study of reproduction and the results of the combination of chromosomes. Gregor Mendel – (1822 – 1884) Austrian Monk who is considered “Father of Genetics” He worked as a Teacher and Gardener He found that plants have “factors” that get passed from one generation to another. (Factors are now called Genes) He found that when two different pea plants were crossed, one factor seemed to disappear in the offspring. It reappears in the next generation

Mendel called the first generation the Parent or “P” Generation. He called the first offspring generation the First Filial or “F1” Generation. The second offspring generation, he called the Second Filial or “F2” Generation. Mendel’s Laws 1. Law of Segregation - Chromosomes separate (segregate) into different gametes during meiosis. 2. Law of Independent Assortment All Chromosomes segregate independent of each other. None are connected to each other

Example of Independent Assortment

A roll of the dice or a flip of a coin Mendel talked about traits and called the genes for those traits alleles. Allele - the different genes for a trait The traits that you got when sperm and egg came together was NOTHING but probability. A roll of the dice or a flip of a coin

Mendel also gave us the genetics terms Dominant and Recessive A trait that will ALWAYS show up if it is in the genes Dominant - Recessive - A trait that will ONLY show up if there are no dominant genes present Example: Your Mom gives you the gene for having a free earlobes (DOMINANT), and Dad gives you genes for attached earlobes (recessive) What are you? Mom Dad Free Free Attached

Recessive lighter color Let’s look at some traits DOMINANT Black color This dog’s genetics could be two ways We show it like this: “B” from one parent, “B” from the other parent OR “B” from one parent, “b” from the other parent “BB” is Homozygous for the trait. “Bb” is Heterozygous for the trait. Recessive lighter color This dog’s genetics CAN ONLY be shown one way: “b” from one parent, “b” from the other parent Recessive traits are ALWAYS homozygous; thus it would be “bb”

X b b B b OK, now for a problem: If I have a heterozygous black male and a golden female that mate, X what is the chances of having golden puppies in the litter? b b B b 50% black 50% golden 100% golden You can make a Punnett square b b Bb Bb 50% B bb bb b

Chart for some human traits So, what is the chances of having a child with dimples if the parents neither have dimples? CC or Cc WW or Ww DD or Dd BB or Bb FF or Ff EE or Ee AA or Aa Cc ww dd bb ff ee aa d d dd dd 0% d dd dd d What is the chances that two Heterozygous dominant, freckled People will have a child with no dimples F f FF Ff 25% F Ff ff f

Definitions to know: Genotype: what the genes say (heterozygous or homozygous). Phenotype: physical appearance of the organism (black or golden).

What do we do if we want to predict the offspring with two traits? Dihybrid Cross: tool used to predict the offspring of parents with TWO traits Ex:

Writing Assignment: On one piece of paper, give your own definition for the following: Dominant Recessive Heterozygous Homozygous Genotype Phenotype On a separate sheet of paper write a two paragraph answer to the following: Knowing what you do about Genetics so far, answer this: In what way can scientists use genetics to determine the traits of offspring of a mating of two individuals. How do animal breeders use genetics to keep traits that they want and get rid of traits they do not want in offspring?

Everything is not always clear cut: Incomplete Dominance: One allele can not completely dominate the other. Codominance: When both dominant alleles show in the offspring. Red White Roan offspring

Type A, Type B, Type AB, Type O Black, Brown Blonde & Red Multiple Allele Traits: Example: Traits having more than one allele that can be found in the population. Human Blood Types Type A, Type B, Type AB, Type O Four distinctly different types Polygenic Traits: Example: Traits that are controlled by several genes at the same time. Human hair color Black, Brown Blonde & Red Four major colors blended through more than a dozen different allele groups.

All of these things are products of selective breeding Genetic Engineering Definition: manipulating the genes of an organism due to selective breeding or microbiological processes Selective Breeding: selecting certain individuals to be the parents of the future generations. All of these things are products of selective breeding

Hybridization: Hybrid Vigor: Crossing two “wild” species to try to get a hybrid with the best traits of the parent species. Hybrid Vigor: Having an offspring species that is better in many ways than either of the parent species

No Is everyone’s DNA the same? DNA “Fingerprints” Karyotyping Def: Isolating differences (variables) in the DNA among groups of organisms. Is everyone’s DNA the same? Karyotyping No Therefore, if we can isolate the differences, we have a unique set of characteristics for the individual. This can involve different methods. Gel Electrophoresis

Gel Electrophoresis: Def: scientist do several things. Take samples of DNA Use enzymes to cut the DNA at specific places Place sample in gels. Use electric current to draw the DNA through the gel Smaller pieces move faster and go further into the gel. The bands differ from person to person.

Karyotyping: This involves catching the chromosomes when they are compacted ready for cell division. Then they must be paired up with their “match” When all the chromosomes in the human genetic makeup are paired, it looks like this: For simplicity, geneticist only use one half of each of the Chromosome to do the matching. Each half is a Chromatid