1 Cellular Division copyright cmassengale

2 Cell Division All cells are derived from pre- existing cells All cells are derived from pre- existing cells New cells are produced for growth and to replace damaged or old cells New cells are produced for growth and to replace damaged or old cells Differs in prokaryotes (bacteria) and eukaryotes (protists, fungi, plants, & animals) Differs in prokaryotes (bacteria) and eukaryotes (protists, fungi, plants, & animals) copyright cmassengale

3 Identical Daughter Cells Parent Cell Two identical daughter cells copyright cmassengale

4 Chromosomes

5 Prokaryotic Chromosome The DNA of prokaryotes (bacteria) is one, circular chromosome attached to the inside of the cell membrane The DNA of prokaryotes (bacteria) is one, circular chromosome attached to the inside of the cell membrane copyright cmassengale

6 Chromosomes in Dividing Cells Duplicated chromosomes are called chromatids & are held together by the centromere Called Sister Chromatids copyright cmassengale

7 Karyotype A picture of the chromosomes from a human cell arranged in pairs by size A picture of the chromosomes from a human cell arranged in pairs by size First 22 pairs are called autosomes First 22 pairs are called autosomes Last pair are the sex chromosomes Last pair are the sex chromosomes XX female or XY male XX female or XY male copyright cmassengale

8 Cell Reproduction watch?v=9nsRufogdoI Mitosis and Meiosis song 3:50min. watch?v=9nsRufogdoI watch?v=9nsRufogdoI copyright cmassengale

9 Types of Cell Reproduction Asexual reproduction involves a single cell dividing to make 2 new, identical daughter cells Asexual reproduction involves a single cell dividing to make 2 new, identical daughter cells Mitosis & binary fission are examples of asexual reproduction Mitosis & binary fission are examples of asexual reproduction Sexual reproduction involves two cells (egg & sperm) joining to make a new cell (zygote) that is NOT identical to the original cells Sexual reproduction involves two cells (egg & sperm) joining to make a new cell (zygote) that is NOT identical to the original cells Meiosis is an example Meiosis is an example copyright cmassengale

10 Cell Division in Prokaryotes Prokaryotes such as bacteria divide into 2 identical cells by the process of binary fission Prokaryotes such as bacteria divide into 2 identical cells by the process of binary fission Single chromosome makes a copy of itself Single chromosome makes a copy of itself Cell wall forms between the chromosomes dividing the cell Cell wall forms between the chromosomes dividing the cell Parent cell 2 identical daughter cells Chromosome replicates Cell splits copyright cmassengale

11 Animation of Binary Fission copyright cmassengale

12 The Cell Cycle copyright cmassengale

13 Five Phases of the Cell Cycle G 1 - primary growth phase G 1 - primary growth phase S – synthesis; DNA replicated S – synthesis; DNA replicated G 2 - secondary growth phase G 2 - secondary growth phase collectively these 3 stages are called interphase M - mitosis M - mitosis C - cytokinesis C - cytokinesis copyright cmassengale

14 Cell Cycle copyright cmassengale

15 Interphase - G 1 Stage 1 st growth stage after cell division 1 st growth stage after cell division Cells mature by making more cytoplasm & organelles Cells mature by making more cytoplasm & organelles Cell carries on its normal metabolic activities Cell carries on its normal metabolic activities copyright cmassengale

16 Interphase – S Stage Synthesis stage Synthesis stage DNA is copied or replicated DNA is copied or replicated Two identical copies of DNA Original DNA copyright cmassengale

17 Interphase – G 2 Stage 2 nd Growth Stage 2 nd Growth Stage Occurs after DNA has been copied Occurs after DNA has been copied All cell structures needed for division are made (e.g. centrioles) All cell structures needed for division are made (e.g. centrioles) Both organelles & proteins are synthesized Both organelles & proteins are synthesized copyright cmassengale

18 What’s Happening in Interphase? What the cell looks like Animal Cell What’s occurring copyright cmassengale

19 Sketch the Cell Cycle Daughter Cells DNA Copied Cells Mature Cells prepare for Division Cell Divides into Identical cells copyright cmassengale

20 Mitosis ?v=VlN7K1-9QB MIN. ANIMATION… ?v=VlN7K1-9QB0 ?v=VlN7K1-9QB0 copyright cmassengale

21 Mitosis Division of the nucleus Division of the nucleus Also called karyokinesis Also called karyokinesis Only occurs in eukaryotes Only occurs in eukaryotes Has four stages Has four stages Doesn’t occur in some cells such as brain cells Doesn’t occur in some cells such as brain cells copyright cmassengale

22 Four Mitotic Stages Prophase Prophase Metaphase Metaphase Anaphase Anaphase Telophase Telophase copyright cmassengale

23 Spindle Fiber attached to Chromosome Kinetochore Fiber Chromosome copyright cmassengale

24 Review of Prophase What the cell looks like What’s happening copyright cmassengale

25 Sketch The Spindle copyright cmassengale

26 Review of Metaphase What the cell looks like What’s occurring copyright cmassengale

27 Anaphase Sister Chromatids being separated copyright cmassengale

28 Anaphase Review What the cell looks like What’s occurring copyright cmassengale

29 Comparison of Anaphase & Telophase copyright cmassengale

30 Cytokinesis Cleavage furrow in animal cell Cell plate in plant cell copyright cmassengale

31 Daughter Cells of Mitosis Have the same number of chromosomes as each other and as the parent cell from which they were formed Have the same number of chromosomes as each other and as the parent cell from which they were formed Identical to each other, but smaller than parent cell Identical to each other, but smaller than parent cell Must grow in size to become mature cells (G 1 of Interphase) Must grow in size to become mature cells (G 1 of Interphase) copyright cmassengale

32 Identical Daughter Cells Chromosome number the same, but cells smaller than parent cell What is the 2n or diploid number? 2 copyright cmassengale

33 Draw & Learn these Stages copyright cmassengale

34 Draw & Learn these Stages copyright cmassengale

35 Eukaryotic Cell Division Used for growth and repair Used for growth and repair Produce two new cells identical to the original cell Produce two new cells identical to the original cell Cells are diploid (2n) Cells are diploid (2n) Chromosomes during Metaphase of mitosis ProphaseMetaphase Anaphase Telophase Cytokinesis copyright cmassengale

36 Mitosis Animation Name each stage as you see it occur? copyright cmassengale

37 Mitosis in Onion Root Tips Do you see any stages of mitosis? copyright cmassengale

38 Test Yourself over Mitosis copyright cmassengale

39 Identify the Stages Early, Middle, & Late Prophase Late Prophase MetaphaseAnaphase Late Anaphase Telophase Telophase & Cytokinesis ? ? ?? ? ?? copyright cmassengale

40 Locate the Four Mitotic Stages in Plants Metaphase Prophase Anaphase Telophase copyright cmassengale

41 Uncontrolled Mitosis If mitosis is not controlled, unlimited cell division occurs causing cancerous tumors If mitosis is not controlled, unlimited cell division occurs causing cancerous tumors Oncogenes are special proteins increase the chance that a normal cell develops into a tumor cell Oncogenes are special proteins that increase the chance that a normal cell develops into a tumor cell Cancer cells copyright cmassengale

42 tch?v=JcZQkmooyPk MITOSIS… MIN. 10 FACTS!!!!!!

Meiosis Gamete Production Gamete Production 43

Meiosis Similar in many ways to mitosis Similar in many ways to mitosis Several differences however Several differences however Involves 2 cell divisions Involves 2 cell divisions Results in 4 cells with 1/2 the normal genetic information. Results in 4 cells with 1/2 the normal genetic information. Vocabulary: Vocabulary: Diploid (2N) - Normal amount of genetic material Diploid (2N) - Normal amount of genetic material Haploid (N) - 1/2 the genetic material. Haploid (N) - 1/2 the genetic material. 44

Meiosis Meiosis results in the formation of haploid cells. Meiosis results in the formation of haploid cells. In Humans, these are the Ova (egg) and sperm. In Humans, these are the Ova (egg) and sperm. Ova are produced in the ovaries in females Ova are produced in the ovaries in females Process is called oogenesis Process is called oogenesis Sperm are produced in the testes of males. Sperm are produced in the testes of males. Process is called spermatogenesis Process is called spermatogenesis Meiosis occurs in 2 phases: Meiosis I & Meiosis II Meiosis occurs in 2 phases: Meiosis I & Meiosis II 45

Spermatogenesis & Oogenesis 46 Sperm formation Egg formation

Meiosis I Prior to division (S phase), amount of DNA doubles Prior to division (S phase), amount of DNA doubles 47

Metaphase I Metaphase I homologous chromosomes EQUATOR During Metaphase I homologous chromosomes line- up along the metaphase plate or EQUATOR connect CHIASMATA Areas of homologous chromosomes connect at areas called CHIASMATA Genes are exchanged at these connections Genes are exchanged at these connections 48

Crossing Over Segments of homologous chromosomes break and reattach at similar locations. Segments of homologous chromosomes break and reattach at similar locations. Results in new genetic combinations of offspring. Results in new genetic combinations of offspring. This is the main advantage of sexual reproduction This is the main advantage of sexual reproduction 49

50 Crossing-over multiplies the already huge number of different gamete types produced by independent assortment Crossing-Over copyright cmassengale

Chiasmata 51

Anaphase I During Anaphase I, each HOMOLOGOUS CHROMOSOME is pulled to opposite sides of the cell. During Anaphase I, each HOMOLOGOUS CHROMOSOME is pulled to opposite sides of the cell. Unlike mitosis, the CENTROMERES DO NOT BREAK. Unlike mitosis, the CENTROMERES DO NOT BREAK. Nuclei MAY OR MAY NOT reform following division. Nuclei MAY OR MAY NOT reform following division. CYTOKENESIS may or may not occur. CYTOKENESIS may or may not occur. 52

Meiosis II DNA DOES NOT double DNA DOES NOT double Chromosomes randomly line-up along metaphase plate like regular mitosis. Chromosomes randomly line-up along metaphase plate like regular mitosis. During Anaphase II, CENTROMERES BREAK and each SISTER CHROMATID is pulled to opposite sides of the cell. During Anaphase II, CENTROMERES BREAK and each SISTER CHROMATID is pulled to opposite sides of the cell. Nuclei reform and cytokinesis usually occurs (although it is often unequal). Nuclei reform and cytokinesis usually occurs (although it is often unequal). Sister chromatids 53

54 Meiosis: Two Part Cell Division Homologsseparate Sisterchromatidsseparate Diploid Meiosis I Meiosis II Diploid Haploid copyright cmassengale

Overview of Meiosis 55

56 Meiosis Animation copyright cmassengale

57 tch?v=16enC385R0w BOZEMAN… MIN. 10 FACTS !!!!!!! tch?v=rqPMp0U0HOA Meiosis..crossing over 6:45 10 facts!!!!!

58 MitosisMeiosis Number of divisions 12 Number of daughter cells 24 Genetically identical? YesNo Chromosome # Same as parent Half of parent Where Somatic cells Germ cells When Throughout life At sexual maturity Role Growth and repair Sexual reproduction Comparison of Divisions copyright cmassengale