1 / 40

The Nucleus Asexual Reproduction: Mitosis & Cell Division

The Nucleus Asexual Reproduction: Mitosis & Cell Division. General Info:. Nucleus: the “brain” of the cell controls the cells activities responsible for cell division, protein synthesis. General Info Cont. Nucleus: contains genetic material called DNA

wedna
Download Presentation

The Nucleus Asexual Reproduction: Mitosis & Cell Division

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The NucleusAsexual Reproduction: Mitosis & Cell Division

  2. General Info: Nucleus: • the “brain” of the cell • controls the cells activities • responsible for cell division, protein synthesis

  3. General Info Cont. Nucleus: • contains genetic material called DNA • DNA long chain (chromatin) of genetic information (eukaryotes) • In prokaryotes (bacteria) DNA is in the shape of a ring called a plasmid

  4. Nucleus Nucleolus Chromatin

  5. Chromosomes: • made of Deoxyribonucleic Acid  DNA wrapped around proteins • Chromosomes in eukaryotes are “rod shaped” structures made of DNA and proteins

  6. Chromosomes: • consist of 2 halves called chromatids • “sister chromatids” are connected in the center by a centromere

  7. Chromosome (Coiled chromatin)

  8. Ck question Topic: DNA and Chromosomes Date: 1-4-2010 • Genetic material of a cell is called … • The location of #1 • The ring of DNA found in Bacteria is… • Chromosomes consist of 2 halves known as…

  9. Chromosome Numbers: • Each species has a characteristic number of chromosomes in each cell. • ex. Fruit flies (drosophila) = 8 chromosomes • horse has 64 chromosomes • humans have 46 and chimpanzees have 48 chromosomes

  10. From 7 characteristics of living things: All living things  Grow • Growth occurs from the division of cells. • Cell Division (cellular reproduction) allows cells to: • Grow in size • Grow in number • Replace worn out, injured or dying cells

  11. 2 Forms of Cellular Reproduction (cell division): • Asexual Reproduction  involves only one parent cell • Occurs in Autosomes or somatic cells … body cells • Plants/animals

  12. 2 Forms of Cellular Reproduction (cell division) Cont… c. protists (protozoan) = single celled organisms (binary fission) d. fungi e. bacteria = binary fission

  13. 2 Forms of Cellular Reproduction (cell division): • Sexual Reproduction involves 2 parents cells • Gametes = sex cells • Making gametes!!!

  14. Sexual reproduction: Occurs in sperm cells and egg cells

  15. The Cell CycleAsexual Reproduction aka MITOSIS The Cell Cycle is responsible for: • birth and death of a cell • Cell division of nucleus, home of hereditary information…chromosomes • Cell division (Cell Cycle) consists in 3 processes

  16. Cell Cycle consists in 3 processes • Interphase • Division of the nucleus=mitosis 3. Division of the cytoplasm = cytokinesis

  17. Ck question Topic: Cell reproduction Date: 1-4-2010 • How many chromosomes does a normal humans have? • Identify 3 reasons cells divide. • The 2 types of cellular reproduction are… • Define gametes. • Define autosome.

  18. Before a cell divides…. Interphase (nucleus) • Cell spends most time here

  19. Interphase: • Divided into 3 phases • G1 – cells grow to mature size • S – DNA is copied or duplicated called DNA replication • G2 – cell prepares to divide • Some cells have a G0 phase, they do not replicate after maturity. Ex. Nervous System

  20. Mitosis: One cell (PARENT CELL) divides into 2 identical cells (Daughters) • divisions: nucleus divides • a series of chronological steps: • prophase • metaphase • anaphase • telophase Division of the nucleus (DNA)!!

  21. Mitosis

  22. Prophase: • Chromatin condenses, becomes visible strands of DNA called chromosomes • 2 chromosomes are made of “sister chromatids” • chromatids are connected by centromere • centrioles in animal cells begin to separate (opposite ends or poles)

  23. Prophase Cont. • spindle fibers form (football shape) from the centrioles and connect to centromere of each chromatid • nuclear membrane fades • chromatids (chromosomes) begin moving to center

  24. Spindle fibers Centrioles Centromere Chromosomes

  25. Metaphase: (middle) • chromosomes (chromatids) line up in the middle of the cell • centromere divide • chromosomes are pulled apart separate chromosomes (???)

  26. Spindle fibers Chromosome Centromere

  27. Anaphase: (away) • centromere divides • chromatids separate • move to opposite ends of cell • complete set of chromatids go to each pole

  28. chromatid

  29. Telophase: • final step of mitosis • chromatids unwind, spindle fibers disappear • nuclear membrane forms around each of chromatids

  30. Cytokinesis: • final step in the cell cycle • cytoplasm (and organelles) divide equally in cells • animals-pinching in of the cell membrane forming a cleavage furrow • plants - cell plate forms across the middle growing outward

  31. In animal cells • (begins outside the cell)

  32. In plate cells • (begins inside the cell)

  33. Results of Mitosis: • division of the nucleus (Asex. Reprod.) • products are 2 new cells with identical information to each other and to the parent cell • most cells reproduce asexually  mitosis • ex. Of cells produced through mitosis include: in animals: blood cells, skin cells, cheek cells, in plants: root cells, stem cells, leaves

  34. Parent Cell Identical Daughter Cells

  35. Identical Daughter Cells Two identical daughter cells Parent Cell

  36. mitosis

More Related