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