1. Cell Division

2. 3.1 Cell Division Cell division occurs in all organisms, but does different things or functions. Unicellular organisms reproduce through cell division. Multicellular organisms use cell division to grow, develop, repair themselves, and reproduce.

3. Genetic Material The genetic material of a cell contains information needed for the cell’s growth and other activities. When a cell divides into two new cells, each cell receives a full set of genetic material. The genetic material is contained in DNA molecules.

4. DNA DNA stands for deoxyribonucleic acid DNA is a molecule that contains information for an organism’s growth and functions. James Watson and Francis Crick discovered the shape of DNA and made a model of it in 1953. They showed that DNA Twists like a ladder or a Double helix

6. DNA and Chromosomes DNA is stored in the nucleus of a cell DNA is wrapped around proteins to be made smaller or more compact in structures called chromosomes. DNA is replicated or copied so each new cell gets a copy.

8. Chromosomes Chromosomes consists of 2 chromatids held together by a centromere. Humans have 46 chromosomes, 23 from mom and 23 from dad

9. Cell Division Cell Division is involved in growth, development and repair. Through cell division a single cell becomes 2, and then they divide into 4 cells and so on. Even when a person, animal or plant stops growing cell division still occurs because old cells need replaced with new ones. Cells don’t live forever Throat cells only last a few days

10. Cell Growth A large organism (animal or plant) does not have bigger cells then a smaller organism, it simply has more cells. Cells grow in size but there is a limit to how big they can grow. If cells get to big they can’t function properly (do their jobs correctly)

11. Cell Development A multicellular organism starts as a single cell and grows into a larger one through cell division. But as an organism develops each cell specializes and takes on a specific job. Blood cells, muscle cells etc. All cells have the same DNA and parts but they perform a specific job.

12. Cell Repair If you have ever had a cut or broken bone, your body has repaired itself through cell division. As cells age and die, they need to be replaced. Some cells last a long time and others wear out quickly Skin cells- age very quickly Brain cells- live very long and don’t get replaced often

14. 3.1 Question: ____is a molecule that contains the information for a cell to grow and develop and is stored in a nucleus. A. Chromosomes B. RNA C. DNA D. Ribosomes E. Water

15. 3.1 Question: DNA is wrapped around proteins to be made into_____. A. Nucleotides B. RNA C. DNA D. Ribosomes E. Chromosomes

16. 3.1 Question: Cell Division helps multicellular animals to ______. A. get smarter B. grow, develop, and get smarter C. grow, develop, and repair D. turn purple E. reproduce

17. 3.2 Cell Cycle Living things grow, reproduce, and die in a process called a life cycle. Cells have life cycles too, called the cell cycle. The cell cycle is the normal sequence of development and division of a cell. Cell cycle has 2 phases Interphase and Mitosis (Cell Division)

18. 3.2 Cell Cycle Interphase is the part of the cell cycle during which a cell carries out its normal functions and it is NOT dividing. Mitosis is the part of the cell cycle during which the nucleus divides. Only eukaryotic cells go through mitosis. The purpose of mitosis is to move DNA and other material in position for cell division. Cytokinesis- division of the cytoplasm and all organelles

19. Interphase: normal activities

20. Mitosis- Division of the Nucleus

21. Cytokinesis- Division of cytoplasm and other organelles

22. 3.2 Cell Division Cell division produces two genetically identical cells- they have the same DNA If a skin cell divides you then have 2 identical skin cells Mitosis has 4 phases- Prophase, Metaphase, Anaphase, and Telophase

24. 3.2 Prophase The first phase of mitosis DNA condenses (becomes smaller) into chromosomes The chromosomes become visible The membrane around the nucleus breaks down

25. First

26. 3.2 Metaphase Second phase of mitosis Chromosomes line up in the middle of the cell

27. 3.2 Anaphase Anaphase is the 3 rd phase of Mitosis The chromosomes split and are pulled to opposite sides of the cell.

28. 3.2 Telophase Telophase is the 4 th phase in mitosis A new membrane forms around the chromosomes to form a nucleus Chromosomes return to their threadlike form

29. Recap Interphase- The cell is doing its daily functions or jobs Mitosis- Nucleus is preparing for Division and there are 4 phases- prophase, metaphase, anaphase, and telophase Cytokinesis- The cytoplasm divides resulting in 2 identical cells.

30. 3.2 Question: ____is the part of the cell cycle during which the cell is not dividing and just carrying out its normal functions. A. Prophase B. Mitosis C. Cytokinesis D. Anaphase E. Interphase

31. 3.2 Question: ____is the division of the cytoplasm at the end of mitosis. A. Prophase B. Mitosis C. Cytokinesis D. Interphase E. Anaphase

32. 3.2 Question: ____ is the phase of mitosis where the chromosomes first appear. A. Metaphase B. Prophase C. Telophase D. Anaphase E. Interphase

33. 3.2 Question: is the part of mitosis where a new nuclear membrane forms and chromosomes turn threadlike. A. Metaphase B. Prophase C. Telophase D. Anaphase E. Interphase

34. 3.2 Question: This is the phase of mitosis where the chromosomes line up in the middle. A. Metaphase B. Prophase C. Telophase D. Anaphase E. Interphase

35. 3.2 Question: This is the phase in mitosis where the chromosomes separate and get pulled to opposite sides of the cell. A. Metaphase B. Prophase C. Telophase D. Interphase E. Anaphase

36. 3.3 Cell Division for Unicellular Organisms For unicellular organisms cell division produces 2 new organisms. This form of reproduction is called asexual reproduction. Asexual reproduction is where a parent organism produces offspring that are genetically identical to the parent. Asexual reproduction involves one parent

37. 3.3 Types of Asexual Reproduction Binary Fission is a type of asexual reproduction and occurs when the parent replicates it’s DNA and then splits in two. Budding- is a process where an organism develops tiny outgrowths called buds which break off to form a new organism. Regeneration- is a process in which missing body parts are replaced. (Starfish, some plants)

39. Binary Fission

40. Budding

41. Sexual Reproduction vs. Asexual Repro. Two parents involved Offspring’s genes are combined from two parents Reproduce more slowly Advantages: increased genetic variation Disadvantages: slower, more energy required, must find a mate One parent organism Offspring’s genes are identical to parents Reproduces quickly Advantages: fast and easy Disadvantage: not much genetic variation

42. 3.3 Question: _____is where a parent organism produces offspring that are genetically identical to them. A. Binary Fission B. Sexual Reproduction C. Asexual Reproduction D. Regeneration E. Splitting in half

43. 3.3 Question: _____occurs when the parent organism replicates its DNA and then splits in two. A. Binary Fission B. Sexual Reproduction C. Asexual Reproduction D. Regeneration E. Mitosis

44. 3.3 Question: ____is the process in which body parts can be replaced. A. Binary Fission B. Sexual Reproduction C. Asexual Reproduction D. Mitosis E. Regeneration

45. 3.3 Question: ____takes longer but results in genetically different offspring. A. Binary Fission B. Sexual Reproduction C. Asexual Reproduction D. Regeneration E. Mitosis