Ch 10 and 11

1. Ch 10 and 11 Cell Reproduction, Mitosis

2. Limits on Cell Size • Diffusion • DNA • Surface area to volume ratio

3. Cell Cycle Cell Growth The sequence of growth and division of a cell Divided into Stages: Interphase Mitosis http://www.cellsalive.com/cell_cycle.htm

4. INTERPHASE Divided into Stages G1 stage (Growth) Rapid growth High protein production S stage (synthesis) DNA made Chromosomes replicates G2 stage (Growth) Other organelles are made Cell prepares for mitosis Majority of the cell’s life is spent in Interphase

5. CHROMOSOME Homologous Pair 2 Main Parts Sister Chromatids Two halves of the doubled structure of a chromosome Centromere Structure that holds sister chromatids together Centromeres (DNA) nonSister Chromatids Sister Chromatids

6. What is Mitosis? • Cell reproduction in which 2 identical cells or daughter cells are made from 1 parent cell • Mitosis results in the growth and repair of the body cells or somatic cells (such as skin, bone, muscles, or liver cell). • http://www.cellsalive.com/mitosis.htm

7. Prophase Centrioles Centrioles pull apart Spindle fibers form Nuclear membrane disappears Nuclear envelope Spindle fibers

8. METAPHASE centrioles Chromosomes attach the spindle fibers Chromosomes line up at the center of the cell chromosomes fibers

9. ANAPHASE centrioles Spindle fibers Centromeres spilt and sister chromatids are pulled to opposite poles Cytoplasm pinches inward Sister chromatids

10. TELOPHASE Nuclear envelope Spindle fibers break down Nuclear membrane reappear 2 identical cells formed Cytokinesis occurs (cell splits)

11. Regulation of the Cell cycle Enzymes (proteins) monitor a cell’s progress from phase to phase during the cell cycle

12. Enzymes are necessary to begin and drive the Cell cycle Enzyme production is directed by genes located on the chromosomes

13. Internal and External Regulation of the Cell cycle

14. Internal Regulation-proteins that respond to events inside the cell; they allow the cell cycle to proceed only when certain processes have happened inside the cell properly Ex: prevents anaphase until all chromosomes are attached to the mitotic spindle

15. External Regulation- proteins that respond to events outside of the cell; they speed up or slow down the cell cycle Example: prevents excess growth of the cell by using chemical messengers (signals) such as hormones (proteins)

16. Causes of Cancer Cancer is the result of uncontrolled cell division Can be both genetic & environmental

17. Environmental factors such as cigarette smoke;

18. air pollution; water pollution & exposure to ultraviolet radiation can cause Cancer Cancer may also be caused by viral infections

19. Cancer Prevention Diets low in fat & high in fiber content reduce the risk of cancer Vitamins & minerals may also help prevent cancers Daily exercise & not smoking

21. TYPES of ASEXUAL REPRODUCTION 3rd set of ch 10 and 11 notes

22. Asexual Reproduction is the production of new organisms without the fusion of nuclei of two specialized sex cells Mitotic Cell Divisions – the new organisms are genetically identical to the parent 1Diploid Cell(2n) 2 Diploid Cells(2n)

23. Binary Fission (evenly) Ex: amoeba, paramecium, (protists) The nucleus divides by mitosis along with cytoplasm to make 2 daughter cells that have the same # of chromosomes

24. Budding The division of cytoplasm is unequal so 1 daughter cells is larger than the other Ex: hydra, yeast

25. Sporulation Spores are made in large amounts that surround themselves with tough coats, large #s Ex: bread mold, fungi, bacteria

26. Vegetative Propogation-new plants are made from roots, stems, or leaves of the parent plant Cutting-new plants develop from cut end of plant, plant stem Ex: coleus, geraniums

27. Bulb-underground stem made from existing bulbs Ex: onions, tulips, lilys

28. Tuber-underground stem with food stored in it Ex: potato

29. Runner-horizontal stem close to the ground Ex: Strawberry

30. Grafting- cut twig attached to trunk or branch of another Ex: flowers, seedless fruits

31. Regeneration (unspecializes=invertebrates) Replacement or regrowth of lost or damaged body parts Ex: lobster, starfish

32. Ch 11 Meiosis 4th set of notes

33. MEIOSIS Process of nuclear division that reduces the # of chromosomes by half It is involved in SEXUAL reproduction It results in haploid(1n) eggs and sperm (animals) and spores that later lead to egg and sperm (plants) [gametes]

34. MEIOSIS It has 2 nuclear divisions : Meiosis I and Meiosis II Also called Gametogensis(Spermatogenesis – sperm (testes) and Oogenesis-eggs (ovaries))

36. Phases of Meiosis IProphase I Nuclear membrane and nucleolus disappears Synapsis occurs (pairing of homologous chromosomes) & crossing-over occurs Tetrad forms (packets of 2 chromosomes) tetrad Crossing-over

37. Metaphase I Homologous chromosomes attach to spindle fibers and move to the equator of the cell

38. Anaphase I Disjunction occurs (homologous chromosomes separate and move to opposite poles)

39. Telophase I Cytokinesis occurs 2 daughter cells form Nuclear membrane reappears

40. Phases of Meiosis IIProphase II Centrioles reappear Similar to mitosis

41. Metaphase II Chromosomes attach to spindle fibers and move to equator of cell

42. Anaphase II Chromosomes split at centromere Chromosomes move to opposite poles

43. Telophase II Cytokinesis occurs in both cells Nuclear membrane reappears 4 cells formed Males – 4 sperm cells Females-1 egg cell & 3 polar bodies

44. Fertilization and Development 5th set of notes for ch 10 and 11

45. Fertilization and Development Fertilization is the union of a monoploid (n) sperm nucleus with a monoploid (n) egg nucleus to form a zygote (2n) cell, the fertilized egg

46. 2 Types of Fertilization: Internal fertilization is the union of sperm and egg in the moist reproductive tract of the female. External fertilization is the union of sperms and egg outside the body of the female; usually done in water.

47. Stages of development: Development begins when the zygote undergoes a rapid series of mitotic cell divisions called cleavage.

48. 4. 8 cells 3. 2. 5. Ball of cells-stem cells 6. Blastula 1.

49. Blastula the formation of a hollow ball made up of one single layer of cells. Gastrulation the process in which one side of the blastula pushes inward or indents; resulting in an embryonic stage called the gastrula

50. Gastuala consists of 3 germ layers: Enduderm inner layer that gives rise to the organs Ectoderm outer layer that gives rise to the skin and nervous system Mesoderm middle layer that forms bonds between the ectoderm and endoderm; gives rise to the muscles, bone, and blood.