What is the differencebetween the hydra’s
offspring growing off of the parent hydra and the two
beetles mating to create their offspring?
How could a cell make an exact copy of itself?
Engage/pH 0708
Remember chromosomes?
Explain/pH 0708
Mitosis
• Mitosis-division of the cell nucleus.
• Cytokinesis-division of the cytoplasm.
Cell Cycle
• During the cell cycle, a cell grows, prepares for division, and divides to form two daughter cells, each of which then begins the cycle again.
Exploring Mitosis
Mitosis
• Cell Division – Cell copying– Creates new cells with identical DNA– If a human cell goes through mitosis, it starts
with 46 chromosomes and ends up with 46 chromosomes in the new cell.
– These cells are called 2n – they have two copies of each chromosome• Diploid
Interphase
• The cell grows and replicates its DNA and centrioles.
Stages of Mitosis-Prophase
• First and Longest Stage of Mitosis
• Chromosomes appear
• Nuclear envelope breaks down
Metaphase
• The chromosomes line up across the center of the cell.
Anaphase
• The chromosomes are separating and moving to opposite sides of the cell.
Telophase
• The chromosomes gather at opposite ends of the cell and lose their distinct shapes.
• Two new nuclear envelopes will form.
• Last phase of Mitosis.
Cytokinesis
• The cytoplasm divides in half.
• Each daughter cell has an identical set of duplicate chromosomes.
Video of Mitosis
• Mitosis Video
The Cell Cycle If a cell “gets stuck” in the cell cycle and divides uncontrollably, a tumor (mass of cells) will form.
The cell is a cancer cell.Cancer cells lose the ability to regulate mitosis and do not recognize the signs to stop dividing (Contact Inhibition).
SOME TUMORS
MRI of Brain Tumor
Asexual Reproduction
• One individual organism creates offspring that are genetically identical to itself.
• This occurs through MITOSIS.– Sea stars, Sea anemones, hydra, some
plants
Hydra Budding
