12/10 Daily Catalyst

1. 12/10 Daily Catalyst • 1. A child is born with blood type O. What are the possible genotypes of the parents? • 2. Give an example of pleiotropy. • 3. A round watermelon is crossed with a long watermelon an all of the offspring are oval. What type of dominance is exhibited?

2. 12/10 Daily Catalyst • 1. A child is born with blood type O. What are the possible genotypes of the parents? • iAi, iBi, or ii • 2. Give an example of pleiotropy. • Gene Q controls the gene for tail length. This gene also controls genes in other body systems. • 3. A round watermelon is crossed with a long watermelon an all of the offspring are oval. What type of dominance is exhibited? • Incomplete dominance

3. 12/10 Class Business • Quiz #12 on Friday • In-class essay on Friday • AP Biology Final Tuesday, 12/17 • Review Monday • Test corrections Wednesday and Thursday • All make-up work is due by 12/19

4. Why was the squirrel mad at Santa? Because he got NUT-in for Christmas

5. 12/10 Agenda • Daily Catalyst • Class Business • Non-disjunction quiz • Grade quiz and review • Notes • Pedigree Explore

6. 12/10 Objective • We will be able to explain how the inheritance patterns of many traits cannot be accounted for by Mendelian genetics.

7. Essential Questions • 1. What is nondisjunction? • 2. When/why does it happen? • 3. What is the result of nondisjunction? • 4. How is nondisjunction related to sex-linked genes?

8. Nondisjunction reading quiz • Directions: On a lined sheet of paper, answer the following questions. You do NOT need to write the questions. When you finish, turn your quiz into the basket and begin working on your packet. • Noise: 0 (silent) • Time: 6 minutes

9. Nondisjunction reading quiz • 1. Define nondisjunction. • 2. In what organisms is polyploidy most common? • 3. T/f:nondisjunction cannot occur during mitosis. If nondisjunction occurs in mitosis, what is the effect of nondisjunction in mitosis? • 4. What is the chromosome number of a trisomic zygote? • 5. What type of alteration of chromosome is exhibited below?

10. Nondisjunction reading quiz • 1. Define nondisjunction. • Homologous chromosomes do not separate properly in meiosis. Results are gametes with extra copies of chromosomes. • 2. In what organisms is polyploidy most common? • Plants • 3. T/f:nondisjunction cannot occur during mitosis. If nondisjunction occurs in mitosis, what is the effect of nondisjunction in mitosis? • False, nondisjunction can occur during mitosis and meiosis. The abnormal number of chromosomes will be transmitted to all cells since cells are exact duplicates.

11. Nondisjunction reading quiz • 4. What is the chromosome number of a trisomic zygote? • (2n+1) • 5. What type of alteration of chromosome is exhibited below? • translocation

12. Note Time • Nondisjunction • Key Point #1: Nondisjunction occurs when chromosomes do not separate from one another • Homologous chromosomes or in sister chromatids • Can be caused by a faulty centromere • Can occur during meiosis AND mitosis

13. Monosomy and Trisomy

14. We are getting to the disorders and the points when inheritance does not follow proper procedure. • Disorders can be inherited recessively and dominantly.

15. Recessively Inherited Disorders • Disorders range from mild to severe (albinism to cystic fibrosis) • Genes code for proteins. An allele that causes a disease may create a malfunctional protein • Key point #2: recessive disorders ONLY show up (phenotype) when the genotype is homozygous recessive (aa)

16. Recessively Inherited Disorders • Heterozygous genotype are phenotypically normal, but are CARRIERS A a At times, homozygous recessive may be lethal, so organisms are never able to reproduce. A a

17. Recessively Inherited Disorders • Tay-sachs: autosomal recessive • Common in Central European Jewish descent • 1 out of 3,600 • Due to geogrpahical isolation ( in gene pool) • High number of aa and Aa • Lacking the enzyme to breakdown fats

18. Recessively Inherited Disorders • Sickle Cell: autosomal recessive • 1 out of 400 African Americans • Due to a substitution mutation in RBC • Heterozygous (Aa) have mild symptoms and make both types of RBC (codominant) • Anti-malarial effects • Heterozygous advantage in evolution

19. Recessively Inherited Disorders • Interbreeding: traits increase in families because recessive traits now become more common and the chance to inherit homozygous recessive traits increase.

20. Dominantly Inherited Disorders • Achrondroplasia: Dominantly inherited (DD or Dd) • Homozygous recessive (dd) not dwarf • Key point #3: dominantly inherited disorders are less common because they are lethal. • Usually kill a cell early in embryonic development • Heterozygous can pass on recessive traits for healthy children

21. Dominantly Inherited Disorders • Huntington’s: Symptoms onset later in life • Lethal dominant allele • Located on Chromosome 4 • Would you want to know?

22. Diseases, environment, and technology • Diseases are affected by multiple factors: diet, physical activity, genetics, environment, etc. • We have used technology to help not only treat, but test for these genetics disorders. • Fetus testing (aminocentesis) • Newborns are screened at birth • Parents are tested • Would you go through genetic testing?

23. Book work • Page 272 • 1, 5, 6, 9, and 12