how do baby animals grow to be adults?. why do animals shed their skin?

How do baby animals grow to be adults?

Why do animals shed their skin?

Cells divide for three purposes:

• Growth of the organism

• Repair damaged structures

• Asexual reproduction

The Cell Cycle - Mitosis

A cell grows, prepares for division, and then divides into two new cells. These two new cells, called daughter cells, are identical to the parent cell because they have the same DNA as the parent cell.

3 stages of the Cell Cycle:

• Interphase

• Mitosis

–Prophase

–Metaphase

–Anaphase

–Telophase

• Cytokinesis

Interphase• Cell spends most of its life in this phase

• The cell grows to its full size

• DNA is copied in the nucleus of the cell

• Cell prepares to divide

Interphase

Prophase

• 1st and longest phase of Mitosis

• Chromosomes become visible

• Centrioles separate and move to opposite ends of cell

• Spindle fibers appear• Nuclear membrane

disappears

Prophase

Metaphase• 2nd and shortest phase of Mitosis

• Chromosomes attach to spindle fibers in center of cell

Metaphase

Anaphase

• 3rd phase of Mitosis

• Centromeres split apart and chromatids separate from each other.

• Chromosomes move to opposite poles

Anaphase

Telophase• 4th and last phase of

Mitosis• Chromosomes reach

opposite poles of cell• Chromatids unwind

back into chromatin• Nuclear membranes

begins to form around the chromatin at each end

• Spindle fibers disappear

Telophase

Cytokinesis• New cell membrane forms between two

nuclei.

• The cell splits into two new cells – each with identical chromosomes.

Cytokinesis

Interphase Prophase

Metaphase Anaphase

Telophase Cytokinesis

Mitosis Review

REMEMBER!REMEMBER!

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