Download Genetics student notes. File

Genetics Notes The Basics/Review. (slides 1 & 2) Use the terms in the box to label the diagram Genes provide instructions for the cell, telling it what proteins to make and which characteristics we will have. What is Heredity? (Slide 3) 1. Besides genes, what else can influence the traits that define you? Provide an example. 2. How many sets of chromosomes does your mother have? _______________________ 3. How many chromosomes does she have? _____________ 4. How many sets of chromosomes does your father have? _______________________ 5. How many chromosomes does he have? _____________ 6. What is conception? 1 7. All the cells in your body contain ______ sets of chromosomes or _______ chromosomes, except for _______________________ or sex cells which only have ________ set or ________chromosomes. 8. What are female sex cells called? ________________________ 9. Your mother gave you ________ set of chromosomes when you were conceived or _______ chromosomes. 10. What are male sex cells called? __________________________ 11. Your father gave you ________ set of chromosomes when you were conceived or _______ chromosomes. 11. What forms when a sperm and egg cell unit? ___________________________ 12. How many cells make up a zygote? ________ 13. How many sets of chromosomes does a human zygote have? ____________ 14. How many chromosomes does a human zygote have? ___________ 15. How many chromosomes do you have? ____________ Vocabulary Word Bank: Gametes Zygote Eggs Sperm 2 Use the terms you have just learned to label the diagram. Each term/number is used only once, and all terms/numbers are used. Gregor Mendel – Monk & Scientists (slides 4-­‐ 14) Isolated “purebred” plants for specific characteristics or traits 13. Experiment #1 involved a cross between? 14. What were the results? __________________________________________________________________. 15. This first cross is referred to as F1 generation. 16. Experiment # 2 involved a cross between? 17. What were the results? ________________________________________________________________. 18 The results lead Mendel to his first law called the Law of Segregation – this states that an offspring obtains genes from both parents and each parent has 2 factors (alleles) for every trait. 3 Alleles will separate during the formation of sex cells and each sperm or egg cell will get only get one allele from each pair. 19. The diagram to the right shows all sets of chromosomes from both parents. Based on this diagram, draw all possible chromosomes sets for chromosome 1 that a child could inherit from their parents. 20. Draw all possible chromosome sets for chromosome 23 a child could inherit from their parents. Since parents contribute chromosomes randomly to each new child, every child inherits a unique set of chromosomes. 21. How many combinations are there for each chromosome 1 through 22?______________. 22. How many combinations are there for chromosome 23? ______________ 23. How many possible complete chromosome sets are there ______________ + _____________ mom dad 246 or 70,368,744,177,644! What does this number tell you? What is a trait? 24. What is a dominant trait? In genetics how is it illustrated? 25. What is a recessive trait? In genetics how is it illustrated? 26. If you were to select a letter to represent a dominant gene for spots on a dog what would the letter be? ___________ What would the letter be for the recessive gene representing a solid coat without spots? ________ 27. The set of genetic information for each form of a gene is called an allele, the letters you wrote above are examples of alleles. 28. If you have two of the same alleles for a trait you will express that trait. 29. If you have 2 dominant alleles for a trait it is called ______________________________________. 4 30 If you have 2 recessive alleles for a trait it is called _____________________________________. 31. If you have 1 dominate and 1 recessive gene it is called _________________________________. Mendel’s second Law of Independent Assortment states that genes will separate independently when sex cells are formed. You do not get 1 identical chromosome from each parent. The genes on that chromosome can cross over and vary. Although Mendel did not see genes he was very perceptive in understanding how traits can be passed on and why we see such variety in all species. Single trait gene traits: Phenotype is the appearance, Genotype is the combination of alleles. 1. Tongue rolling: Dominant (R) non-­‐rolling is recessive (r). Your phenotype Roller or non roller? Your possible geneotype(s) ___________ ____________ 2. Hand clasping: Clasp your hands together, notice whether your left or right thumb is on top. If the left is on top you have a dominant trait (C), the right on top is recessive (c). Your phenotype? ______________________________________ Your possible geneotype(s) ___________ ____________ 3. Widow’s peak – The action of a dominant gene (W) results in a hairline that forms a distinct point in the middle of the forehead. The straight hairline is recessive (w). Your phenotype? ______________________________________ Your possible geneotype(s) ___________ ____________ 4. Dimpled chin – a cleft in the chin is a dominant trait (D) while the absence of a cleft is recessive (d). Your phenotype? ______________________________________ Your possible geneotype(s) ___________ ____________ 5