1. Heredity

2. Reflection Questions…… Using your graph answer the following using complete sentences – page 68 Did you share a trait with another classmate? Did you find a trait that was unique to you? Why do some of the traits have such a big difference in the number of students that have the trait and the number that do not have the trait? If we took a poll of the entire school would the results be similar? Explain your answer.

3. Vocabulary to Know! START YOUR FLASH CARDS NOW allele chromosome codominance DNA dominant allele gene genotype heredity heterozygous homozygous pedigree phenotype Punnett square recessive allele trait

4. Gregor Mendel Gregor Mendel is known as the father of Genetics He was an Austrian Augustinian monk and scientist who studied the inheritance of certain traits in pea plants

5. What did Mendel do?? Gregor Mendel had two significant discoveries in the mid-nineteenth century: The first is that organisms have “factors” or what is more commonly known as genes, that control their physical traits Secondly, organisms pass on their genes to their offspring in predictable ways

6. Because of Gregor Mendel……. Scientist can now predict the likelihood that children, not yet conceived may inherit certain diseases Scientists are also using this knowledge of genetics to alter the biology of plants, animals and humans.

7. Heredity Heredity refers to the passing of traits from parents to their offspring. Genes control the traits that appear in those offspring. When organisms reproduce, they give genes to their offspring, and those genes cause traits to appear.

8. More About Heredity Each gene is a small piece of a long complicated molecule called DNA. DNA is an abbreviation for Deoxyribonucleic Acid. In the reproductive process, DNA arranges itself into structures called chromosomes found in the nucleus of the cell.

9. Write the term that matches each definition. 1.A section of a DNA molecule that controls a trait is called ___________________. 2.The passing of traits from parents to offspring is known as ___________________. 3._____________________ is a complicated molecule that contains genes. 4.A characteristic in an organism ___________________. 5.The structure into which DNA arranges itself: ___________________.

10. Answers! A section of a DNA molecule that controls a trait is called a Gene The passing of traits from parents to offspring is known as Heredity DNA is a complicated molecule that contains genes. A characteristic in an organism: Trait The structure into which DNA arranges itself: Chromosomes

11. Phenotype and Genotype Phenotype – Scientists can study traits by examining how organisms look on the outside. The outside expression of a gene is called a phenotype. Example: Chris has a widow’s peak. A scientist will say that Chris is expressing the widow’s peak phenotype.

12. Phenotype and Genotype Genotype – Humans have two copies of each gene, called alleles, one from the biological mother and one from the biological father. When a scientist determines which two alleles a person has, they are determining the person’s genotype.

13. Dominant vs. Recessive A dominant allele causes a widow’s peak in humans. Scientists use an upper case letter (W) to indicate a dominant allele and a lowercase letter (w) to indicate a recessive allele. The widow’s peak gene has three possible genotypes: WW, Ww, or ww. Chris has a widow’s peak. Therefore we know that he has at least one dominant allele. His genotype is either WW or Ww.

14. Homozygous vs. Heterozygous If a person has two identical alleles, in Chris’s case, if he has WW as his genotype, then he is homozygous dominant for the trait. If a person has a dominant and a recessive allele, in Chris’s case, if he has Ww as his genotype, then he is heterozygous. Amy doesn’t have a widow’s peak. Write the letters for her genotype. ____________ What is Amy’s genotype: homozygous dominant or homozygous recessive? ______________________

15. Heterozygous or Homozygous?? AA ____ Bb ____ Cc ____ Dd ____ Ee ____ ff ____ GG ____ HH ____

16. Punnett Square A Punnett square shows the possible combinations of alleles that children can inherit when two people produce offspring. The Ameba Sisters help us to understand! https://www.youtube.com/watch?v=i- 0rSv6oxSY&index=14&list=PLwL0Myd7Dk1F0i QPGrjehze3eDpco1eVzhttps://www.youtube.com/watch?v=i- 0rSv6oxSY&index=14&list=PLwL0Myd7Dk1F0i QPGrjehze3eDpco1eVz