Cell Reproduction Mitosis Meiosis Medical ppt http hastaneciyiz

Cell Reproduction Mitosis & Meiosis Medical ppt http: //hastaneciyiz. blogspot. com

http: //biotech-adventure. okstate. edu/low/basics/mitosis-diagram/diagram. gif

Cell Cycle http: //www. bmb. psu. edu/courses/biotc 489/notes/cycle. jpg

Mitosis • One type of cell division Cell process in which the nucleus divides to form two nuclei identical to each other, and identical to the original nucleus, in a series of steps (prophase, metaphase, and telophase)

Mitosis allows for growth and replaces worn out or damaged cells.

Interphase • Period of growth & development • Hereditary information (DNA) copied (replicated / duplicated) • Cells that do not divide (nerves) are always in interphase

http: //biotech-adventure. okstate. edu/low/basics/mitosis/phases/interphase. gif

Prophase • DNA begins to shorten & thicken –Now called chromatids / chromosomes • Centromeres form • Nuclear membrane breaks apart • Spindle fibers form

http: //biotech-adventure. okstate. edu/low/basics/mitosis/phases/prophase. gif

Metaphase • Chromatids / chromosomes line up • Centromere attaches to spindle fibers

http: //biotech-adventure. okstate. edu/low/basics/mitosis/phases/metaphase. gif

Anaphase • Centromeres divide • Spindle fibers shorten • Chromatid pairs separate – move to ends of cell • Chromatids are now called –Each ½ of the pair is now called a chromosome

http: //biotech-adventure. okstate. edu/low/basics/mitosis/phases/anaphase. gif

Telophase • Spindle fibers disappear • Chromosomes uncoil • Nuclear membrane forms • Cell divides (cytokinesis)

http: //biotech-adventure. okstate. edu/low/basics/mitosis/phases/telophase. gif

Interphase Prophase Metaphase Anaphase Telophase Interphase http: //biology. nebrwesleyan. edu/benham/mitosis/

Mitosis Animation http: //www. johnkyrk. com/mitosis. html

Results of Mitosis • Division of nucleus – Nuclei are identical to each other • Same number & type of chromosomes

Asexual Reproduction A type of reproduction - fission, budding, and regeneration - in which a new organism is produced from one parent and has DNA identical to the parent organism.

Asexual Reproduction • Offspring produced from one organism • Hereditary information is identical • Mitosis is one form of asexual reproduction

Sexual Reproduction Meiosis

Sexual Reproduction A type of reproduction in which two sex cells, usually an egg and a sperm, join to form a zygote, which will develop into a new organism with a unique identity.

Sexual reproduction results in a great variety, or diversity, of offspring.

Meiosis • The nucleus divides twice – Meiosis II

http: //biotech-adventure. okstate. edu/low/basics/meiosis/diagram/

Interphase • DNA is duplicated

Prophase I • DNA shorten & thicken – Forms chromatids / chromosomes

http: //biotech-adventure. okstate. edu/low/basics/meiosis/phases/prophase/leptotene. gif

Metaphase I • Copied chromatids / chromosomes line up in middle of cell • Centromeres attach to spindle fibers

http: //biotech-adventure. okstate. edu/low/basics/meiosis/phases/metaphase-I. gif

Anaphase I • Chromatid pairs are pulled apart –They DO NOT separate • Move to ends of cell

http: //biotech-adventure. okstate. edu/low/basics/meiosis/phases/anaphase-I/anaphase-i. gif

Telophase I • Cell divides • No further replication of hereditary material

http: //biotech-adventure. okstate. edu/low/basics/meiosis/phases/telophase-I. gif

There are now two cells. Both cells have full sets of genetic material (chromosomes)

Prophase II • Similar to mitosis –Starts with TWO cells instead of one • Spindle fibers appear

http: //biotech-adventure. okstate. edu/low/basics/meiosis/phases/prophase-II. gif

Metaphase II • Duplicated chromatid / chromosomes line up in middle of cell • Spindle fibers attach to centromeres

http: //biotech-adventure. okstate. edu/low/basics/meiosis/phases/metaphase-II. gif

Anaphase II • Centromere divides –Chromatids separate & move to ends of cell • Chromatids are now individual chromosomes

http: //biotech-adventure. okstate. edu/low/basics/meiosis/phases/anaphase-II. gif

Telophase II • Spindle fibers disappear • Nuclear membranes form at each end of cell • Cells divide –Results in 4 cells • Each with ½ the original number of chromosomes

http: //biotech-adventure. okstate. edu/low/basics/meiosis/phases/telophase-II. gif

Meiosis Animation http: //www. johnkyrk. com/meiosis. html

In summary: Meiosis • Two cells form during meiosis I • In meiosis II, both of these cells form two cells • The two divisions of the nucleus result in four sex cells (gametes) • Each has one-half the number of chromosomes in its nucleus that was in the original nucleus Medical ppt http: //hastaneciyiz. blogspot. com