Presentation on theme: "1 1 Asexual Reproduction presents: Mrs. Stewart Honors Biology: Cell Growth and Division."— Presentation transcript:
1 1 Asexual Reproduction presents: Mrs. Stewart Honors Biology: Cell Growth and Division
How do little elephants grow up to be BIG elephants? BELL WORK
Are the cells of the adult elephant larger than those of the baby? BELL WORK
CLE Describe the relationships among genes, chromosomes, proteins, and hereditary traits. 11/01/11
Evaluate the reasons for asexual reproduction in organisms Differentiate between the different stages of the cell cycle in terms of order of occurrence, and chromosome location 11/01/11
What do they look like? How many do humans have? They look like an “X” just before the cell divides and an “I” after they divide. 46 (23 pairs) (23 from mom, 23 from dad)
There are two different types of cell division Which type is performed depends on the kind of “daughter cells” that are desired Mitosis = identical daughter cells with same amount of DNA Meiosis = genetically different daughter cells with half the amount of DNA 11/01/11
Somatic Cells Every cell in the body EXCEPT reproductive cells Have all 46 chromosomes Gamete Sexual reproduction cells (Example: sperm for males, Ova/eggs for females) have half the amount DNA (23 chromosomes)
Somatic 11/01/11 OR Gametes
11/01/11 Why do animals shed their skin? THINK – PAIR - SHARE
11/01/11 How does a cut heal? THINK – PAIR - SHARE
Three reasons why cells reproduce by asexual reproduction: 1. Growth 2. Repair 3. Replacement 11/01/11
Cell Membrane not large enough to maintain needs coming in/going out DNA, used for protein synthesis, cant keep up with demands Organelles unable to keep up with demands (ie: waste removal)
Which phase does the cell spend the most time in? Interphase
Time between cell divisions 90% of a cell’s life 3 phases: 1.G1: Growth and everyday activities 2.S: DNA replication 3.G2: preparation for Mitosis (production of necessary proteins/organelles)
The process of dividing the nucleus to create two daughter cells, identical to the mother cell Mitosis
11/01/11 Mitosis Creates two daughter cells that are identical to each other AND identical to the parent cell Creates diploid cells (two sets of chromosomes in each daughter cell) Allows organisms to grow Allows organisms to replace damaged/worn out cells P-M-A-T-C
11/01/11 The DNA (chromatin) organizes into chromosomes The nuclear membrane disappears Centrosomes (centrioles) move to opposite ends of cell
11/01/11 Chromosomes attach to spindle fibers (by their centromeres), and line up at the center of the cell Spindle Fibers – microtubules that help separate chromosomes during division
11/01/11 Chromosomes separate at the centromere, and the sister chromatids are pulled toward opposite ends of the cell.
11/01/11 Chromosomes disorganize and the nuclear membrane begins to reform.
11/01/11 The division of the cell cytoplasm, usually beginning during Telophase and finalizing the production of two new daughter cells. Each new cell will have about ½ of the cytoplasm and organelles of the parent cell.
11/01/11 CLEAVAGE FURROW VS. CELL PLATE ANIMAL Cleavage furrow indentation of the cell membrane to form two separate cells Plants Cell plate A cell wall is rigid and cannot flexibly move and pinch together to separate the newly formed cells. So, a cell plate forms between the two new cells. This cell plate will harden and become a cell wall for each.
Interphase Prophase Metaphase Anaphase Telophase Cytokinesis I PLAY MUSIC AT THE CLUB 11/01/11 I P M A T C