1. Gregor Mendel

584-586 on the History of Genetics and the Work of Gregor Mendel. Study the pictures and. Use this link to view A Kid's Guide To The Life Cycle Of A Flower. The scientist Gregor Mendel is considered the father of genetics because he made the first major discoveries in how genes and their characteristics are passed.

Is a molecule that contains the information to make proteins. Proteins, along with water, sugars, fats and DNA, constitute your cells and create the chemicals to make your body function. Your DNA is protein's recipe. It contains the unique formula for you. If you look at DNA through an electron microscope, you see a structure that resembles a ladder twisted into a spiral shape called a double helix. The twisted strands of DNA are very elegant and beautiful. The design of you comes from that amazing work of art, itself to create the same exact pattern over and over again in each new cell as your cells divide.

Gregor Mendel's Cool Beans. A 19th-century Austrian monk, named, was the first person to solve the mystery of why traits appear generation after generation. Gregor Mendel experimented with garden peas in his monastery to find out why two different plants in the same species produced certain characteristics time after time. He crossed plump round peas with wrinkly peas - and got all round peas. Then he pollinated those round-seeded plants together and got some round peas and some wrinkled peas. This was how he discovered. The recessive trait - wrinkled peas - reappeared in about every fourth plant after the first generation.

The same thing happened when he worked with yellow plants and green plants. The yellow plants were dominant, and the greens were recessive. Mendel didn't have a powerful microscope or know anything about genes, chromosomes and DNA.

However, he discovered and wrote about the principles that scientists use to examine genetics today, so we call him the 'Father of Genetics' for his groundbreaking work. Dominant and Recessive The patterns work like this: two genes for blue eyes, one from mom and one from dad, will give you blue eyes. A pair of genes for tallness will make you grow like a weed. Same for attributes like blond or curly hair, skin color, heavy or delicate bones, nearsightedness, and farsightedness. As long as you get the same genes from both parents, those characteristics will show up as you. Dominant genes are the strongest and are usually labeled with a capital letter - 'B' for brown, for instance. Recessive genes are typically hidden by dominant genes.

Label the recessive gene for blue eyes 'b' - lowercase. If you get two dominant genes for eye color - BB - you're a brown-eyed beauty. Inherit a dominant and a recessive gene - Bb - you get the dominant color: brown.

When both parents contribute a recessive gene, in this case blue-blue or bb, you've got blue eyes. That's the basic version. Genetics is a little more complicated than that. You can inherit traits that are in your parents' DNA but that aren't expressed. For example, your brown-eyed dad may pass along the gene from his blue-eyed great grandfather.

Match that to your mom's blue-eyed gene, and you've got baby blues, even with a brown-eyed dad. Be a Geneticist Extract your DNA using plain household ingredients! It's the real deal - but you might want some help from those parents who conveniently loaned you their chromosomes. You can't see the double helix without a very sophisticated science lab and expensive electron microscope. You can from your spit with a sports drink, soap and ice-cold alcohol. Materials. Small paper cups (dentist-office size).

Lemon Ice Gatorade, or any clear sports drink. Clear liquid dish soap. One tablespoon of pineapple juice. 90 percent to 100 percent isopropyl alcohol. A clear (glass or plastic) test tube with a stopper.

Test tube stand or a small jar or glass to hold it. One skinny wood or bamboo skewer Directions. Put the alcohol in the freezer the night before. (It won't freeze, but you need it ice-cold.). Set all of your equipment on a table in a well-lit space. Take a big swig of the sports drink and swish it around in your mouth, the way you rinse at the dentist.

Use your teeth to gently scrape the sides of your mouth as you swish, to loosen more cheek cells. Swish a lot - count to at least 100. Spit the sports drink into a paper cup. Pour the contents of the paper cup into the test tube until you've filled the tube about 1/3. Carefully add just enough dish soap to fill the test tube halfway. Put the stopper in the tube.

Put your thumb on the stopper and rotate the tube back and forth, up and down, a few times. Don't shake it - you don't want a bunch of bubbles or foam. Uncap the test tube. Add a couple of drops of pineapple juice - just drip a few drops into the mix. Then stopper and rotate the test tube again. Retrieve the alcohol from the freezer and unstop the test tube again. Tilt the test tube so you can pour a slight trickle of alcohol into the tube.

You want the cold alcohol to float on top of the rest of the mix. It helps to trickle the alcohol down the side of the tube - take your time. Place the test tube in the holder and let it rest upright for at least one minute. As soon as you see a layer of white gooey stuff between the alcohol float and the rest of your cheek-cell spit cocktail, slowly poke the skewer into the test tube, so its tip touches the white goo. Swirl the skewer gently in one direction, so the goo wraps around it, and you can pull your DNA sample out of the test tube. What's Happening The sports drink contains salts that help to break down cell membranes to release DNA.

Detergent attracts both fat and water molecules, so the liquid dish soap helps to pull the fats and water from the cells away from the DNA. The enzymes in the pineapple juice break down the cell membranes even more.

DNA dissolves in water but not in alcohol. So the cold alcohol 'pulled' the DNA out of the liquid solution. It collected just under the alcohol float, and that's when you could see it. Strands of DNA naturally want to coil, so they will wrap themselves around a skewer if you only spin it in one direction.

If you want to keep your DNA around for a while to admire it, plop it into a clean, empty baby food jar in some alcohol. You can use this experiment to extract DNA from fruit like strawberries or kiwis.

Spells it out for you. Fun Flabbergasting Facts.

All people with blue eyes had a who lived some time between 10,000 and 6,000 years ago. The of genetic traits is red hair and blue eyes. Both of those genes are recessive, and only one percent of humans have the combination.

Every single human has some genes from a common ancestor, a woman who lived at least 200,000 years ago whom scientists call '.' You inherit those genes from your mother. If you hate to eat your broccoli, blame it on your genes. Some people have inherited taste buds that react strongly to the and other plants in the Brassica genus.

Broccoli may be good for you, but tell that to your tongue. Good luck sharing this handy fact with your mother. Bananas are a genetic cross called a hybrid., from Africa, were hard, not very tasty, and full of seeds. Humans experimented with different variations to create the seed-free, sweet and soft fruit we eat today.

Human and gorilla DNA are 98 percent the same. People are than to other apes, such as orangutans. A single chromosome determines whether you are a boy or a girl. Girls have two 'X' chromosomes; XX equals female. Boys have one 'X' chromosome and one - XY.

The DNA in a single cell of your body is longer than you are. If you stretched all your DNA strands straight and laid them end-to-end, the ribbon would be about of the entire solar system. More to Explore The American Museum of Natural History has an interactive online website, Ology, that offers tons of activities on its page.

Explore cool models you can make, experiments to try, and a cloning section all about Dolly the sheep. DNA is Here to Stay by Dr. Fran Balkwill is a kid-friendly, wonderfully illustrated clear look at genetics accessible to school age children but crammed with easy-to-grasp information for older kids as well. Try your library or an for a new or used copy.

Genes are Just the Beginning Genetics is a fascinating and developing science with many mysteries to unravel. It reveals a lot about why living things look and act the way they do. Farmers and botanists experiment to find the healthiest plants with the most blossoms or fruit, or carefully preserve heirloom species for future generations. Animal breeders match males and females of a species with the best traits to produce vigorous offspring. A test can sometimes tell you whether you have inherited a family gene for a health problem. Genetics gives you information you can use.

But it doesn't define you. Your environment has a big effect on your health, how you learn, what activities you choose, or whether you have a sunny or solemn disposition. In the end, genetics can explain a great deal about you. However, the real force of nature that decides how to shape your life is you.

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Peas in a pod: Genetics of this extension. Introduction All children are curious about why they look the way they do. Adults frequently comment to them that they have their 'mother's eyes' or their 'father's chin.'

This lesson plan will introduce children to the basics of heredity in an approachable way. Genetics is a subject that can occupy an entire lifetime of study, and this lesson is meant to be an introduction. If your child is interested in further exploration, please see the extension activities at the end of the lesson plan. Learning Objectives After completing the lessons in this unit, students will be able to:.

Understand the basics of genetics. Create a Punnett Square. Apply understanding of genetics basics to reality-based problems Lesson 1: Introduction Genetics is the study of how you became the way you are.

Everyone inherits traits, or qualities, from their parents, but before Gregor Mendel, no one was quite sure how that happened. Even smart scientists like Charles Darwin had it all wrong.

They thought traits were blended like paint. They believed that if a tall person and a short person had a baby, the baby would be of medium height.

Then, in the 1800s, along came Gregor Mendel, a priest with an interest in science and horticulture (the study of plants). He was very curious about how traits were passed from one generation to another. He started experimenting with mice, but people complained, so he switched to peas. He experimented with peas (29,000 plants!) for seven years and used mathematical principles to figure it all out. That brings us to a question: when someone says two people are as alike as peas in a pod, what does that truly mean? How alike are two peas in a pod?

Mendel found out they can be very different. He identified eight different traits that followed the pattern he devised, although it turns out there are many more. Lesson 2: Traits Mendel determined that traits aren't blended but are instead passed on, intact, from parent to child. He found that everyone got two genes for each trait — one from the mom and one from the dad. Believe it or not, at the time it was a big deal to figure this out. He also concluded that some traits are dominant and some are recessive.

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Dominant traits show up even if you also have a different gene for the same trait; the gene that doesn't show up is the recessive one. For example, if you have a gene for dimples in your cheeks and a gene for no dimples, you will have dimples because dimples are a dominant trait. The way you look on the outside is called your phenotype; the way you really are deep down in your genes is called your genotype. One of the most amazing things Mendel discovered was how traits appeared to skip a generation. Mendel took a tall pea plant and crossed it with a short one. He expected medium pea plants, but what he got was all tall pea plants!

Mendel then crossed these tall babies (he called them the F1 generation) and he got three tall plants and one short plant! What's up with that? He used what is called a Punnett Square to show what happened. T T t Tt Tt t Tt Tt Originally, we know one parent is tall and its genotype is TT (remember, we're talking about what you look like in your genes, and you have two alleles, or gene options, for each trait), so we put those letters on one side of the square. The other parent is short and its genotype is tt, so we put those letters on the other side.

Every baby plant gets an allele from each of them. So when they have four pea babies, look what happens! Look carefully at the square.

What do each of these pea babies look like? They're all tall because, in peas, tall is dominant. Are they all truly tall deep down in their genotype? They're half tall and half short, but the short doesn't show on the outside (their phenotype). T t T TT Tt t Tt tt The really amazing thing is when the F1 Generation has pea babies. We call them F2 (they're the grandbaby pea plants of the first group).

Looking at this Punnett Square, can you tell how many look tall? (Hint: the ones with a big 'T' look tall).

How many look short? How many look tall but are really a combination? Because three look tall, we call this a 3:1 phenotypic ratio. Whoa, hold on there! We're using math! We'll do more of that later, but think of it this way: there are four possibilities, right? Of the four, three look tall, and how you look is your phenotype.

So, we have three tall to one short in this generation. Can you figure out the genotypic (what it really is, not just what it looks like) ratio if we go in order of all tall, hybrid (mixed), all short? What did you get? Check the 'Did you know' section on the next page to find out if you're right. Mendel figured this same thing out with eight different traits found in peas.

Not everything about you is inherited this way (the things that are we call 'Mendelian traits'), but other scientists have found out that more than 4,000 traits are! Did you know?. People used to think that eye color was a Mendelian trait, but it turns out it's not. If you have sticky earwax, it's in your genes. You'll feel right at home in Europe, where 90 percent of people do. However, only 4 percent of Chinese have sticky earwax.

David could have explained to Goliath that his gigantic size was a Mendelian trait. Do you think he would have had as much success impressing Goliath with a drawing of the Punnett Square of his genotype as he did with the slingshot?. Almost 100 percent of Native Americans have type O blood. Lots of things we inherit aren't all good or all bad. For instance, people with sickle-cell anemia are more resistant to malaria than people without it.

Humans have 46 chromosomes, dogs have 78, and butterflies have 380. Like many ground-breaking scientists, Mendel's work was rejected during his lifetime and was only rediscovered in the 1930s and 1940s.

Answer to ratio question above: Did you get 1:2:1? That's correct. Ideas to remember: Can you answer these questions with words you've learned?. I want to use the word that describes what determines the trait. I don't want to use 'gene' — I want a different word. What word could I use?. You see a person on the street with dark, curly hair.

Are you seeing genotype or phenotype?. If I have the alleles for two different traits, but one is showing, then the trait that is showing must be what?. If you can see me at the level that isn't what I look like but rather is what I really am in my alleles, what is that level called?. Your friend comes to you with information about his parents' alleles and wants you figure out the odds that he will inherit a particular trait. What kind of diagram can you use to do this?. I have type O blood. How likely is it that my parents do, too?

Can you draw out some possibilities? Some other cool words:.

Homozygous: The same, like when you have two of the same allele for some trait. For instance, if you have two alleles for blue eyes, you are homozygous for that trait.

Heterozygous: Mixed, like when you have two different alleles for some trait. For instance, if you have one sticky ear wax allele and one non-sticky, you are heterozygous for that trait. Hybrid: This means heterozygous or mixed. In a Punnett Square, it's written with one big letter and one small one, like this: Tt. Mendelian Traits: These are traits governed by only one genetic locus (fancy word for 'place') and only two alleles. These are also called 'simple traits.'

. Principle of Segregation: This says that for any trait, the pair of alleles from each parent separate and only one of them is passed on to their child. This means that, even though your mom and dad each have two alleles for each trait they have, they only pass on one to you — you get one from each of them. That's fair, right? Lesson 3: The math of Mendel I love math.

Especially ratios. I also love bad jokes.) I love Mendel Math because Gregor Mendel loved ratios.

He liked probability, too, so I think you'll probably like that. Let me tell you about ratios first. I know you're saying to yourself, 'Horatio, what do I care about ratios?'

Well, let me tell you, you use ratios all the time. For instance, let's say you buy a bag of candy and your mom makes you share it with your brother. You divide it fairly — say, one piece for him, two for you — until the bag is gone. In the end, for every two pieces of candy you have, he has one. It doesn't matter if there were 30 pieces or 120, it's still the same. You now have a two-to-one ratio of your candy to his. That takes a long time to write, so we put it like this: 2:1.

Ratios can be very helpful because, if your brother tattles to your mom that you didn't divide the candy fairly, you can just tell her you used a 2:1 ratio to do it. She will be so impressed that she won't care that you cheated your brother. See how it works? Mendel used ratios to describe what happened in his experiments without using a lot of words. Instead of saying, 'There were three tall plants and one short plant in the such-and-such generation,' he just wrote '3:1 ratio tall to short' and everyone knew what he meant. So, if there were 16 plants altogether and 12 of them were tall plants, there would be four short plants because, for every three tall ones, there would be one short one. How simple is that?

Ratios are easy, and I love easy. If it weren't for loyalty to my fantastic name, I'd probably like probability even more than ratios. Probability is very cool! Have you ever asked your dad if you can stay up until midnight on a school night? If so, he probably said, 'Your chances are slim and none.' Well, probability tells you exactly what he means by that.

Probability is ranked on a scale of 0 to 1. One is something that is definitely going to happen — like the probability that your mom is going to make you brush your teeth sometime this week is 1. A zero is something that is definitely not going to happen.

For instance, your teacher is definitely not going to tell you that, because you're such a great kid, she's going to buy you a new skateboard and let you ride it in the hall at school. The probability of that event is 0. If it's not, will you tell me who your teacher is?) Most things or events fall somewhere in between, so they're a fraction because all the numbers between 0 and 1 are fractions, or pieces. So if there are four people in your family and your dad brings home a cake and cuts it into four pieces, the probability of your getting one of them is one out of four, or ¼, right? (Well, if you bribe him, your chances might change, but that's a different thing.) Mendel used probability to explain why things didn't always do what he thought they would when he grew all those peas.

(By the way, do you think he made people eat all those peas? Just wondering.

I like peas almost as much as bad jokes.) Anyway, you know already that if two pea plants that were each hybrid (heterozygous) for tall (Tt) were cross-cultivated to grow another generation of pea plants, we'd expect three of the babies to look tall and one to look short, right? Well, it doesn't always work out exactly that way. With every new baby plant, you start over with your chances. You have a 3 out of 4 chance of getting a tall baby pea plant, but you might get three short plants in a row because every time you grow a baby pea plant, your chances are 1 in 4 that you will end up with a short one. What happens, though, is that if you raise a lot of pea plants, you will see that 3:1 ratio you were expecting. This is called the Law of Large Numbers. It makes me happy just to say that phrase: Law of Large Numbers.

No, really, try it. If you want to learn more about probability (What am I saying 'if' for?), check out our. Assessment You will now be the geneticist! D D D DD DD d Dd Dd. Imagine that a family comes to you to help them determine if a child claiming to be their long-lost daughter really belongs to them.

In the first meeting, you notice that both parents have dimples. You test their blood, and you find out that the mother has the recessive gene for no dimples, so although her phenotype (what she looks like) has dimples, her genotype was mixed, dimples/no dimples.

This Punnett Square shows what their children's genotypes are likely to be:. You test the long-lost daughter's blood and find out that her genotype is Dd. Let's say you notice that they have sticky earwax, too, but she doesn't. Since sticky earwax is dominant, that makes you suspicious.

Is it possible that she is their daughter?. Create a Punnett Square as if the parents are both heterozygous (mixed) for sticky earwax. Label the earwax gene 'E.' .

How likely is it that they would have a child without sticky earwax?. If I get a box of 100 pieces of candy, and I share it with my sister at a 3:1 ratio. (Of course the 3 is me! It's my candy!) How many pieces will my sister receive?.

Can you design a scenario similar to the one in question 1 in which the girl can be proved not to be the couple's daughter?. What do you think is the most important thing about Mendel's discovery?. Remember that blood type is co-dominant, meaning that if you have one allele for A and one for B, you will be AB. Neither is dominant to the other. With that in mind, create the Punnett Square for a couple whose blood types are both AB. Assessment key Extension.

Watch the movie Lorenzo's Oil about a boy with a rare genetic disease. With what you know about blood typing, try your hand. Read a book on genetics:. National Geographic investigates: Genetics from DNA to Designer Dogs by Kathleen Simpson. Genetics (What's the Big Idea?) by Martin Brookes. Watch.

Explore the. The NIH is also home to. Find at the Michigan Genetics Resource Center.

See how many questions on you can answer with what you learned. This series of lessons was designed to meet the needs of gifted children for extension beyond the standard curriculum with the greatest ease of use for the educator.

The lessons may be given to the students for individual self-guided work, or they may be taught in a classroom or a home-school setting. Assessment strategies and rubrics are included at the end of each section. The rubrics often include a column for 'scholar points,' which are invitations for students to extend their efforts beyond that which is required, incorporating creativity or higher level technical skills. This is just a sample Lorem ipsum dolor sit amet, consectetur adipiscing elit.

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Gregor Mendel

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