Cell division

2. Mitosis and Meiosis Timothy G. Standish, Ph. D.

4. Fertilization Results In A Diploid Zygote Egg 1n Haploid nucleus Sperm 1n Haploid nucleus

5. Fertilization Results In A Diploid Zygote Sperm 1n Egg 1n Haploid nucleus Haploid nucleus

6. Fertilization Results In A Diploid Zygote Sperm 1n Egg 1n Haploid nucleus Haploid nucleus

7. Fertilization Results In A Diploid Zygote Sperm 1n Egg 1n Haploid nucleus Haploid nucleus

8. From Zygote to Embryo Zygote 2n Zygote 2n

9. From Zygote to Embryo Cleavage

10. From Zygote to Embryo Cleavage

11. From Zygote to Embryo Cleavage

12. From Zygote to Embryo Cleavage

13. From Zygote to Embryo Morula

16. The Cell Life Cycle G1 M G2 S Gap 1 - Doubling of cell size. Regular cellular activities. transcription and translation etc. Synthesis of DNA - Regular cell activities cease and a copy of all nuclear DNA is made Gap 2 - Final preparation for division Mitosis - Cell division

20. Stages Of Mitosis Mother cell Interphase Anaphase Telophase Metaphase Mitotic spindle Prophase Nucleus with un-condensed chromosomes Equator of the cell Condensed chromosomes Disappearing nuclear membrane Poles of the cell Two daughter cells Metaphase plate

21. Packaging DNA B DNA Helix A T T A G C C G G C T A T A G C C G G C T A A T Histone proteins Histone octomer 2 nm

22. A T T A G C C G G C T A T A G C C G G C T A A T Packaging DNA B DNA Helix Histone octomer Histone proteins 2 nm

23. A T T A G C C G G C T A T A G C C G G C T A A T Packaging DNA Histone octomer B DNA Helix Histone proteins Nucleosome 11 nm 2 nm

24. Packaging DNA A T T A G C C G C G G C T A A T

25. Packaging DNA A T T A G C C G C G G C T A A T

26. Packaging DNA “ Beads on a string” Tight helical fiber Looped Domains A T T A G C C G C G G C T A A T Protein scaffold 11 nm 30 nm 200 nm

27. Packaging DNA Metaphase Chromosome G C A T Protein scaffold 700 nm 11 nm 30 nm 200 nm 2 nm Looped Domains Nucleosomes B DNA Helix Tight helical fiber

28. Chromosomes, Chromatids and Centromeres Centromere Chromosome arm Chromosome arm Two identical chromosomes Replication Identical chromatid Chromatid Anaphase A packaged chromosome

29. Chromosome Morphology Chromosomes can be distinguished on the basis of size and the relative location of centromeres. Chromosome arm Chromosome arm Centromere Submetacentric Acrocentric Telocentric Metacentric q arm p arm petite

31. p53

38. Stages Of Meiosis: Meiosis I Interphase Mother cell Meiosis II Prophase I: Tetrad formation/ crossing over Metaphase I Telophase I Prophase I: Condensing Chromosomes Anaphase I

39. Stages Of Meiosis: Meiosis II Telophase I The products of mitosis are 2 diploid cells with identical chromosomes. The products of meiosis are 4 haploid cells each with a unique set of chromosomes. Prophase II Metaphase II Anaphase II Telophase II

40. Crossing Over Because of crossing over, every gamete receives a unique set of genetic information. Prophase I: Tetrad formation/ crossing over Anaphase I Telophase II Metaphase I Telophase I

41. The End