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Which factors determine the way we look?

Which factors determine the way we look?. CST Review-Introduction to Meiosis and Fertilization. BI5. a. Students know the general structures and functions of DNA, RNA, and protein.

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Which factors determine the way we look?

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  1. Which factors determine the way we look? CST Review-Introduction to Meiosis and Fertilization

  2. BI5. a. Students know the general structures and functions of DNA, RNA, and protein. • BI1. d. Students know the central dogma of molecular biology outlines the flow of information from transcription of ribonucleic acid (RNA) in the nucleus to translation of proteins on ribosomes in the cytoplasm. • BI2. a. Students know meiosis is an early step in sexual reproduction in which the pairs of chromosomes separate and segregate randomly during cell division to produce gametes containing one chromosome of each type. • BI2. b. Students know only certain cells in a multicellular organism undergo meiosis. Standards:

  3. explain the genetic factors that influence the way we look. • recognize that DNA contains the genetic information that determines the way we look. • explain the structure and function of DNA. Objectives:

  4. Review-The Cell Cycle-DNA is copied and the cell divides

  5. Review-DNA contains the information to make more cells (in the nucleus).

  6. The central dogma describes the flow of information from DNA to RNA to proteins. (Review)What is the central dogma?

  7. Double helix=twisted ladder • Chromosomes=chains of DNA and proteins. • Contains your genetic info (instructions to make proteins) • Sequences of DNA=Genes • Genes=codes for proteins=instructions for traits DNA Basics

  8. If DNA contains the info to make cells, and we are made of cells…then DNA determines our cellular and molecular make-up which determines what we look like. DNA

  9. Why do we look like our parents, but not exactly like our parents?

  10. ½ your chromosomes from your momma • ½ your chromsomes from big poppa • You have 23 pairs of chromosomes (46 total) Where does our DNA come from?

  11. Homologous chromosomes- chromosomes that each have a corresponding chromosome from the opposite-sex parent • Crossing Over – exchange of portions of chromatids, genetic recombination Meiosis Vocabulary

  12. Scientific name–gametes (sperm and egg) • In humans, gametes have 23 chromosomes (haploid=1 set) • Half of 46 • Fertilized egg contains 23 chromosomes from each parent (diploid= 2 sets) What are sex cells?

  13. Two stages (Meiosis I & II) • Meiosis 1-divides homologous chromosomes, crossing over • Meiosis 2-divides sister chromatids • 1 diploid cell produces 4 genetically different haploid cells What happens during meiosis?

  14. Meiosis

  15. Sex cells (gametes) are produced by our parents (meiosis) and then fuse together during fertilization to combine their genetic information (chromosomes). • That’s why we look like our parents, but not exactly like our parents. How does the DNA get from our parents to us?

  16. Fertilization

  17. Perfection!!!

  18. Describe the structure and function of DNA. • How many chromosomes are in human body cells? Where do the chromosomes come from? • Which types of cells are produced during meiosis? • What occurs during fertilization? • What are the major events of Meiosis I and Meiosis II? Summary Questions:

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