Bio 263, Unit 1 Review: Cell Cycle & Mitosis, Negative & Positive Feedback

G1 (post mitotic), S (synthesis), G2 (pre-mitotic), G0 (amniotic cells)

Interphase. Cell regains normal size, very active. Varies in length of time.

Interphase. Cell manufactures second set of chromosomes.

Interphase. Cell produces additional organelles and cytoplasm needed to divide.

Interphase – amniotic cells. Don’t reproduce outside of womb (ie, neurons, myocardial cells).

Prophase, metaphase, anaphase, telophase, cytokinesis

Nucleoli and nuclear membranes disappear. DNA condenses into chromosomes. Centrioles separate and move to opposite ends of cell, anchored by astral fibers. Spindle fibers stretch from centromere to centriole on each DNA strand.

Chromosome pairs line up in middle cell on metaphase plate.

Spindle fibers shorten and pull chromosomes to opposite poles of cell.

Prophase events are reversed; nuclear membrane & nucleoli reforms, chromosomes become chromatin

Cell separates along cleavage furrow

Begins with a stimulus that triggers a body response. The response triggers a stronger stimulus, which causes a stronger response. Two examples: parturition & blood clotting. Seen in disease processes.

A stimulus (internal or external) is perceived that triggers a response. The response corrects the stimulus.