Organism of the Day: Pink Fairy Armadillo The smallest of the family of the armadillos, the Pink Fairy Armadillo, Chlamyphorus truncatus, exists in parts of Argentina in South America. It is threatened by the destruction of its habitat and domestic dogs. It can be distinguished from the other members in the family, because it is the only armadillo with the dorsal shell almost completely separated from the body. This little digger can bury so fast that it can bury itself in a matter of seconds when it feels threatened. The armor plate functions as a cork to close the entrance to its burrow. They feed primarily on ants. Questions: 1. If this Armadillo has gametes that have 21 chromosomes, how many chromosomes are present in a diploid nerve cell? 2. Because this organism is a mammal, we know that their sex chromosomes consist of ____ for males and ____ for females. 1 ` Biology Thursday/Friday May 3/4, 2012 1. Organism of the Day: Pink Ferry Armadillo 2. Review Homework 3. Review DNA Notes 4. Genetics and Meiosis Notes 5. Start Homework Announcements Due Today: Read 12.1 and answer questions 1 ­ 3 on page 343 and 12.2. Due Monday: Read 11.1 and answer assessment questions 1 ­ 2 and read 11.4 and answer assessment questions 1 ­ 4. Biology EOC: EcologyReview: Sunday April 29th or Tuesday May 1st in room 311 Cell BiologyReview: Sunday May 6th or Tuesday May 8th in room 312 EvolutionReview: Sunday May 13th or Tuesday May 15th in room 326 2 Turn in Homework 3 Review DNA Structure Structure of Deoxyribonucleic Acid Hydrogen bonds (week Sugar­Phosphate Backbone • Sides run anti­parallel • Sugar = deoxyribose • Phosphate = PO4 makes DNA very negative Nitrogenous bases=rungs • Adenine • Thymine • Cytosine • Guanine Chargaff’s Rule • A=T (2 hydrogen bonds) • C­G (3 hydrogen bonds) 1 sugar + 1 phosphate + 1 base = a nucleotide 4 Genetics Notes 5 Genetics Notes 6 Genetics Notes 1. Genetics 2. Fertilization 3. Trait 4. Hybrids 5. Genes 6. Alleles 7. Principle of Dominance 8. Segregation 9. Gametes 7 Video Meiosis Notes I. Meiosis I ____________________ separate (each pair Homologous Pairs contains 1 copy of the chromosome from mom and one from dad). a. ____________________ chromosomes replicate ­­> Interphase sister chromatids. b. Prophase I chromosomes of each homologous pair are _____________ (Each pair has 4 chromatids)Partnered up *Genes are swapped in the process = _____________________.crossing over line­up c. Metaphase I: Homologous pairs ____________ (2 lines) d. Anaphase I: Homologous pairs _____________separate e. Telophase I and Cytokinesis: after cytokinesis each new cell contains ____ chromosome from each one homologous pair. Result: ___ haploid, daughter cells that contain sister 2 chromatids. 8 Meiosis Notes II. Sexual Reproduction: when the __________________ of two parents Chromosomes combine to produce offspring. a. The chromosomes that combine during sexual reproduction are contained in special cells called ______________ eg) eggs, Gametes sperm, and _______ (in some plants).Spores b. In humans, each gamete has ________ 23 chromosomes (haploid #). All other human cells (somatic cells) have ____ chromosomes 46 (diploid #). c. Definition of Meiosis in ____________ diploid cells: the process by which organisms produce haploid gametes. 9 Meiosis Notes 10 Meiosis Notes 11 Meiosis Notes III. Meiosis II ______________________ separate (like Mitosis)chromatids a. Chromosomes ______________ go through Interphasedon't b. Prophase II: chromosomes _____________condense c. _____________ sister chromatids lineup in the center of the Metaphase II cell. Anaphase II d. _____________ sister chromatids separate and go to either side. e. Telophase II and ______________: new nuclei form and Cytokinesis membrane divides. Result: ___ haploid, daughter cells.4 12 Meiosis Notes 13 Meiosis Notes 14 15 Meiosis Notes IV. Meiosis vs. Mitosis A. Cells divide twice during meiosis…. __ cell1 __cells4 B. Meiosis distributes a ______________ mixture of maternal random and paternal chromosomes to each gamete C. _________________ in meiosis adds to the genetic variety crossingover of the gametes 16 Meiosis Notes 17 Meiosis Activities Order the pictures with your partner, then answer the questions below in your notes. 18 Start Homework 19 Exit Question A gamete is haploid/diploid while a zygote is haploid/diploid. Reminders Due Monday: Read 11.1 and answer assessment questions 1 ­ 2 and read 11.4 and answer assessment questions 1 ­ 4. 20.