Mendel's Laws

Master Mendel's Laws! Learn genetics with our interactive worksheet on heredity.

Gregor Mendel: The “OG” of Genetics Born in 1822 in Austria, Gregor Johann Mendel would grow up to become the “Father of Modern Genetics”. Fast forward to nearly two centuries later, and scientists are still using Mendel’s principles of heredity to understand how genes are passes from parent to offspring.Believe it or not, Mendel’s groundbreaking discoveries didn’t take place in a fancy science lab…they took place in a garden. When Mendel was living in a monastery (a place where monks live) he became fascinated by the pea plants in the garden. He wondered how these peas plants could have so many different traits and what was causing theses plants of the same species to have different appearances.Mendel experimented with the pea plants by intentionally crossing peas with plants with specific traits. For example, he crossed a tall pea plant with a short pea plant (called the Parent Generation, or the P Generation). The result was all tall plants in the offspring (known as the F1 Generation). Then he allowed those offspring to self-pollinate. In the new generation (known as the F2 Generation) there were three tall plants and one short plant. This was shocking at the time! The shorter trait has seemed to “disappear” in one generation and “reappear” in the next. 1. Gregor Mendel is considered the Father of..... DNA Double Helix Evolution Modern Genetics Geology 2. Which trait seems to sometime "disappear" between generations? Dominant Recessive The Law of Segregation Mendel focused his research on seven different traits of pea plants, including things like seed color, seed shape, plant height, and flower position. The result of his experiments led him to some important generalizations about inheritance known as Mendel’s Laws. Mendel’s first law, the Law of Segregation states that every individual organism has two alleles for each trait (one from the mother and one from the father) that separate randomly during anaphase of meiosis so that each gamete (or sex cell) only contains one of the two alleles. So, each parent can only give one allele for a trait to their offspring. 3. Complete the following statement by clicking on the blanks and choosing the correction word(s) to complete the it. The Law of Segregation states that every individual organism has two alleles for each trait (one from the mother and one from the father) that separate randomly during anaphase of meiosis so that each gamete (or sex cell) only contains one of the two alleles. So, each parent can only give one allele for a trait to their offspring. The Law of Independent Assortment Mendel’s second law, the Law of Independent Assortment states that alleles for separate traits are passed to gametes independently of one another. By studying so many traits of pea plants, he was able to confidently state that the trait of seed color, for example, did not influence the trait of plant height. Tall plants didn’t always have green seeds, they sometimes had yellow seeds. Those alleles are passed to gametes separately from each other and do not influence each other. 4. Complete the following statement by clicking on the blanks and choosing the correction word(s) to complete the it. The Law of Independent Assortment states that alleles for separate traits are passed to gametes independently of one another. Those alleles are passed to gametes separately from each other and do not influence each other. The Law of Dominance Mendel’s third law, the Law of Dominance is now one that we understand to be very important today – some alleles are dominant, while others are recessive. An organism with at least one dominant allele will display the dominant trait. This is why that recessive “short” trait in pea plants was to “reappear” – it was being masked by the dominant trait in the F1 Generation. The only way a recessive is trait is expressed, is both gametes have the recessive allele. 5. Complete the following statement by clicking on the blanks and choosing the correction word(s) to complete the it. The Law of Dominance states that an organism with at least one dominant allele will display the dominant trait. The only way a recessive is trait is expressed, is both gametes have the recessive allele. 6. Match Mendel's Laws with the correct description by clicking on the law in the left column and the correct description in the right column. A line will be drawn between the two. Law of Segregation When gametes are formed during meiosis, each gamete receives just one gene copy, which is selected randomly Law of Independent Assortment Alleles for separate traits are passed independently of one another. Law of Dominance Some alleles are dominant and some are recessive, an organism with at least one dominant allele will display the dominant trait. 7. Classify each characteristic below by clicking on it and choosing the correct law it is describing. You should have 3 characteristics for each law. Law of Segregation When gametes are formed during meiosis, each gamete receives just one gene copy, which is selected randomly. Occurs during anaphase of meiosis. Each parent can only give one allele for a trait to their offspring. Law Independent Assortment Alleles for separate traits are passed to gametes independently of one another. One trait does NOT influence another trait. Alleles are passed to gametes separately from each other and do not influence each other. Law of Dominance An organism with at least one dominant allele will display the dominant trait. The only way a recessive is trait is expressed, is both gametes have the recessive allele. Some alleles are dominant and some alleles are recessive. 8. Complete the table by clicking on the table and choosing the correction option. Law Statement of the Law Additional Information Law of Segregation When gametes are formed during meiosis, each gamete receives just one gene copy, which is selected randomly. Occurs during anaphase of meiosis. Law of Independent Assortment Alleles for separate traits are passed independently of one another. One trait has does not affect the inheritance of another trait. Law of Dominance Some alleles are dominant and some are recessive, an organism with at least one dominant allele will display the dominant trait. The only way a recessive is trait is expressed, is both gametes have the recessive allele. 9. Which Mendel Law explains why a tall plant may pass a tall allele to a gamete or a short plant allele to a gamete? Law of Dominance Law of Segregation Law of Independent Assortment 10. Which Mendel Law explains why during his pea plant experiment the recessive “short” trait in the pea plant was able to “reappear” after it was being masked by the dominant trait in the F1 generation? Law of Dominance Law of Segregation Law of Independent Assortment 11. Which Mendel Law explains why some tall plants have yellow peas and some tall plants have green peas? Law of Dominance Law of Segregation Law of Independent Assortment 12. Which Mendel Law is bein demonstrated with the image below? Law of Dominance Law of Segregation Law of Independent Assortment 13. Which Mendel Law is being demonstrated in the image below? Law of Dominance Law of Segregation Law of Independent Assortment 14. Which Mendel Law is being demonstrated in the image below? Law of Dominance Law of Segregation Law of Independent Assortment