What is the difference between 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