1. Growth and Reproduction Characteristic of all living things – Growth 2 options – Cells can become larger (unicellular and multicellular) – More cells produced (multicellular) Needed for success of the individual – Reproduction 2 options – Asexual or sexual Needed for the success of the species/population

2. Growth and Reproduction Based on portion of cell theory – All cells come from preexisting cells Genes and chromosomes were inherited from previous generations – Parents, grandparents, great-grand, etc Continuation of life is dependant on this – Information must be passed from cell to cell, generation to generation Information is in the form of DNA for all living things DNA stored in chromosomes

3. Cell Size Cells are small – Surface area to volume limitation – 0.0004-0.0008 inches 100 trillion cells in a typical human – All cells are about the same size – Cell size and shape relate to function Remember: Structure determines function – Cells of organisms are all about the size Muscle cells of a whale is the same size as that of a mouse Whale just has more cells

4. Limitations on Cell Size All base on surface area to volume ratio Limited by 4 main factors – Availability of nutrients – How much cytoplasm the cell can control Supply with nutrients/remove waste – Relation of surface area and volume – Location of the cell Different cells have different jobs  different size

5. Differentiation/Specialization Found in multicellular organisms Have cells designed to complete specific task Cells take on characteristics to help the organism meet needs All cells have the same genetic info within an organism – DNA in a muscle cell is the same as a nerve cell

8. Major Terms for Mitosis Traits: daughter and parent cells have the same traits – Characteristics passed from parent to offspring – Height, eye color, hair color, facial structure, blood type, to many more to list

9. Major Terms for Mitosis Heredity: transmission of traits between generations – Information is carried in the chromosome – Asexual All genetic information comes from one parent Offspring are identical to the parent – Sexual ½ genetic info from each parent Human: 23 chromosomes from mom, 23 from dad

10. Major Terms for Mitosis Genes: Segment of DNA which controls hereditary traits – Points on chromosomes that control certain traits – Estimated number of human genes is currently at 20,000-25,000 Human genome project

11. Major Terms for Mitosis Chromatin – How the genetic information is organized when a cell is not dividing Uncoild Genes available to read Nucleic acid wraps around proteins – Proteins called histones

12. Major Terms for Mitosis Chromatid – Identical copies of the same genetic information – Each cell gets one when cell divides – Held together by a centromere

13. Binary Fission 1 parent cell divides into 2 daughter cells Binary Fission – Carried out by bacteria – Method of asexual reproduction – Bacteria only have 1 chromosome, no nucleus – Very simplistic division Can happen very rapidly E. Coli will colinize infant gastrointestinal tract within 40 hours (needed for survival)

15. Mitosis Process of cell division when chromosomes in the nucleus of the parent divide into 2 identical sets Cells produce daughter cells that contain same DNA as the parent – Daughter cells are genetic copies of the parent Involved in asexual reproduction of eukaryotes

16. Stages of the Cell Cycle Interphase (G1, G0, S, G2) Mitosis (M) – Prophase – Metaphase – Anaphase – Telophase Cytokinesis(C)

17. Interphase Period between division Genetic info in the form of chromatin Majority of a cells life When normal cell function is carried out

18. Interphase G1: Cell grows – Right after cell was produced from parent – Must get to functional size G0: When a cell does not divide – Nerve, muscle (in adults), kidney, liver S: Synthesis of DNA – DNA is copied in preperation for division – Each new cell will need its own copy G2: Growth and preparation for division

19. Prophase First stage of mitosis Chromatin shorten and thicken making visible chromosomes Each chromosome consist of 2 chromatids Chromatids held together by centromere Nuclear envelope starts to break down Nucleolus breaks down Centrioles (Centrosome) become visible

21. arm centromere

22. daughter chromosomes sister chromatids

23. Prophase

24. Metaphase Chromosomes move to the middle of the spindles between the two poles Line up side by side at the equator Chromatids attach to spindle fibers at the centromere Chromosomes are thick and coiled

25. Metaphase

26. Anaphase Chromatids separate and are pulled to opposite poles Ends when chromatids reach the sides Once they are split from each other they are considered a chromosome Each pole contains the same number of chromosomes as the parent cell

27. Anaphase

28. Telophase Exact opposite of prophase Chromosomes become fine threads (chromatin) Spindle fibers disappear Nuclear membrane reforms Nucleolus begins to reform

29. Cytokinesis Cytoplasm of the cell divides Produces 2 new daughter cells Cell pinches in forming a cleavage furrow Cell plate is formed in organisms with a cell wall

30. Cytokinesis

31. Reproduction Sexual reproduction – Union of 2 reproductive cells to form new cells – Requires meiosis – Reproductive cells called gametes Male = spermFemale = egg

32. Reproductive Terms Gamete – Cell with only half the number of chromosomes – Sperm/egg – Why do they need ½ genetic information?

33. Reproductive Terms Fertilization – Fusion of 2 gametes Zygote – Result of 2 gametes being fused – First cell of a sexually reproduced organism

34. Reproductive Terms Diploid – Cell with the complete number of chromosomes – Called somatic cells – 46 in a human (2n) Haploid – Cell that has half the number of chromosomes – 23 in human (n)

35. Reproductive Terms Meiosis – Cell reproduction that produces cells with haploid number of chromosomes – Broken into Meiosis I and Meiosis II Similar to mitosis cell cycle Everything happens twice – Except intephase – Do not need to reproduce genetic information between – Meiosis I Separates homologous pairs – Meiosis II separates chromatids

36. Asexual Reproduction 1 parent Offpring are exact copies of parent – One get copies of one parents chromosomes Several types based on organism Benefits – Quick, large amount of offspring, low energy input, difficulty of finding mate (sessile) Draw backs – Little/no genetic variation

37. Binary Fission Simple form of asexual reproduction Unicellular organism splits into two identical organisms

38. Budding Growth of a reproductive fragment from a parent Contains complete genetic information – Limited cytoplasm

39. Spore production Spores protected by hard shells Can survive harsh conditions

40. Vegatative Propagation Asexual in plants Make clone of themselves Why do plants need to be able to reproduce a sexually?

41. Meiosis Cycle Interphase Meiosis I Cytokinesis I Meiosis II Cytokinesis II

42. Meiotic Interphase Very similar to interphase for somatic cells Cell grows, DNA copied, cell prepares for division

43. Prophase I Very similar to Prophase from mitosis Crossing over happens – Homologous pairs exchange genetic information – Group together in a tetrad Tetra = 4 – Allows for more diversity in the population – What are homologous pairs?

44. Prophase I

45. Metaphase I Homologous pairs line up on metaphase plate Moved by spindle just like mitosis

46. Metaphase I

47. Anaphase I Separates the homologous pairs Creates huge possibility for genetic variation – Called independent assortment Amount of possible combinations is 2 n For Humans: 2 23 = 8,388,608 possible combinations

49. Metaphase II Chromosomes align on the metaphase plate again

50. Sister chromatids separated

51. Overall Meiosis Meiosis I : Separates Homologous Pairs Meiosis II: Separates sister chromatids