Do Now

1. Do Now • Write out the question, likely to see again: • With the use of your notes, explain how with the use of only blood types (type A, B,…), a person can only be ruled out as a potential father but not positively determined to be the father. • Hint deals with dominant & recessive traits. • Answer: • If the blood types are different then no parental involvement, but if they match then it is only a possibility.

2. Homework • 1. For Tuesday: Read pages 395 – 397 Read and take notes including the following: • Sex-linked genes • X-Chromosome Inactivation • Pedigree

3. Homework due already! • 1. Gattaca Worksheet & Summary due Friday • 2. Read pages 392 – 394 Read and take notes including the following: • Karyotype X & Y Chromosomes • Co-dominant Multiple Alleles • Genome Autosomes • Sex Chromosomes • Research paper Due today in class.

4. One more time with this • Explain Hitler’s “Master Race” • Blonde Hair & Blue Eyes. • Blonde hair – Is it dominant or a recessive trait? • Answer – Recessive (BB or Bb would be dominant). • Blue eyes- Is it dominant or a recessive trait? • Answer – Recessive (GG or Gg would be dominant). Are they heterozygous or Homozygous? • Homozygous. Why is this considered to be more pure? • Because it can only be Blonde & Blue eyes because bbgg (Homozygous), unlike BB/Bb & GG/Gg (which could be homozygous or heterozygous)

5. One more time with this • Explain Hitler’s “Master Race” • How would you set up a Punnett Square for this meaning what are the phenotypes and genotypes? • Phenotypes – Blonde Hair & Blue Eyes • Genotypes – bb (Blonde Hair) & gg (Blue Eyes) for Mom and the same for Dad: • bbgg & bbgg

6. For the Master Race Do the following – Blonde Hair & Blues eyes mom & dad bbgg for mom and bbgg for dad . No dominants bgbgbg bg • bg • bg • bg • bg

7. Genetics • For reproduction to occur two things must occur: • 1. Off spring inherit a single copy of each parent • Term is called what? • Segregation • 2. The sex organs must be separate so that each contain one set of genes. For example: males XY & females XX

8. Genetics • In humans, we have 23 sets of genes for a total number of chromosomes of 46.

9. Genetics • In humans, we have 23 sets of genes for a total number of chromosomes of 46. Errors do occur such as Downs, were one extra chromosome appears. In Downs it appears on 21. Can occur on 18 too.

10. Genetics • Most chromosomes are homologous – meaning each of the chromosomes has a pair from mom and from dad. • A cell containing both sets of homologous chromosomes is called diploid (2 sets). • Some cells contain only a single set of chromosomes called haploid.

11. New Material • Most follow the principle of dominance – meaning if a dominant allele appears then the dominant trait will express itself. • Hair color – BB, Bb or bb • (P. 394) Blood type for example, known as Rhesus. Rh+ & Rh- (Rh+ is the dominant) so an individual with Rh+ & Rh- will be Rh+ same as hair color. • Slightly different – Co-dominance & Multiple alleles such as in the ABO Blood group • This is determined by from 3 different alleles Ia Ib and i. Alleles Ia & Ib are both co-dominant, i is recessive. (look at chart on page 394. Please re-read codominant & multiple alleles.

12. New material • What is color blindness?

13. New material • Sex-linked inherence: • Colorblindness for example. Carried on the X chromosome. For a female to carry the recessive gene she would have to have it on both the X chromosome. Since males only have one X chromosome it cannot be cancelled out with the other sex chromosome gene since it is Y. • This is why it is far more likely to find a male with color-blindness than a female.

14. Inbreeding • Continuous breeding of an individual with similar characteristics. • What is the danger? • Too close to one another genetically so both the good genes and the bad can remain, and be expressed. Much like the Amish where after a few generations there is very little variation.

15. New stuff • X-Chromosome inactivation – in females since there are two X-Chromosomes, one of the X-Chromosomes typically is shut off. Sometimes they are both on, sometimes both off. • When shut off it is called inactivation. • In male cats, for example, since there is on one X-Chromosome, the cat will only have one additional color of fur.

16. Pedigree • Looks at the pattern of inheritance. The pedigree looks at the presence or absence of a particular trait. • For example looking Sickle Cell Anemia or hemophilia.

17. Human genetic Disorders • Sickle Cell Disease is most often found in people of African ancestry. • People with Sickle Cell Disease have a defective allele for beta-globin found in hemoglobin. Hemoglobin is the oxygen carrying protein in red blood cells. • The defect makes the Hemoglobin less soluble, causing Hemoglobin molecules to stick together and be less effective. • The molecules clump together giving them the half-moon shape and these get stuck in capillaries causing blood to clot.

18. Human genetic Disorders • Cystic Fibrosis is most often found in people of European ancestry. • It develops because three bases did not form. • This is a genetic trait, many people are carriers of the disease and never know it because they have no signs of it. They must mate with someone that is also a carrier of CF. • CF effects the lungs ability breath properly.

19. Typhoid Mary • Irish cook Mary Mallon (1869-1938) was dubbed "Typhoid Mary" by the media after she infected dozens of people with the dreaded disease. • When Mallon worked as a cook at the turn of the century, typhoid fever was a highly contagious disease and a serious threat to the public health. Mallon was the first identified person who carried and spread the disease without ever exhibiting the symptoms. At least three deaths and 53 cases of typhoid were directly linked to her, with thousands of other probable cases.

20. Was she immune or just a carrier? • Some question as to whether she had CF in some form. Many in Europe (those most affected by CF) had developed a resistance to typhoid. The CF allele blocks the entry of bacterium typhoid. Those with a heterozygous for CF would develop an immunity.

21. Gene therapy • Gene therapy is a technique for correcting defective genes responsible for disease development (four types) • 1. A normal gene may be inserted into a nonspecific location within the genome to replace a nonfunctional gene. • 2. An abnormal gene could be swapped for a normal gene. • 3. The abnormal gene could be repaired through selective reverse mutation, and returns it normal function

22. Gene therapy continued • 4. The regulation (the degree to which a gene is turned on or off) of a particular gene could be altered.

23. Human Genetic Disorders • Cystic Fibrosis- in your own words explain • 1. What does it do? • 2. How does it occur? • Sickle Cell Anemia • 1. What does it do? • 2. How does it impact?

24. Advantage of a genetic disorder? • Cystic Fibrosis – Thought to prevent Typhoid from occurring. In old Europe typhoid was common and the body seems to have adapted to prevent it by developing CF.

25. Sickle Cell Anemia • Remember that evidence points to higher survival rates for Africans where Malaria exists. Sickle Cell seems to have mutated and allowed Africans to survive in areas where Malaria exists

26. Nature’s way to deal with change • Organisms that face environmental change have 3 choices • 1. Adapt to the change in environment • 2. Move away from the new condition • 3. Die