MITOSIS and INTERPHASE

What are the three parts of the cell theory?

Cells are the basic structure and function of life, all living things are made of cells, and all cells come from existing cells.

Why do old cells make new cells?

Because the body is changing, such as when healing a skin cut or undergoing growth.

Why can't old cells just get bigger instead of dividing?

Because of DNA overload (DNA doesn't grow with the cell and can't control it) and difficulty exchanging materials through the cell membrane.

What process do old cells go through to make new cells?

The cell cycle.

What are the two main phases of the cell cycle?

Interphase and M phase (mitosis and cytokinesis).

What is the primary goal of the cell cycle?

To obtain two genetically identical daughter cells by copying everything inside the cell and dividing in two.

What are the three sub-phases of Interphase?

G1 phase, S phase, and G2 phase.

What happens during the G1 phase of Interphase?

All of the organelles are copied.

What happens during the S phase of Interphase?

DNA is copied (replicated). Most of the cell's time is spent in this phase.

What happens during the G2 phase of Interphase?

The cell finishes any organelle copying that was not completed in the G1 phase.

What three features indicate a cell is in Interphase?

The nuclear membrane is clearly visible, DNA is in the form of chromatin (loose fibers), and centrioles are paired up together in the corner.

What is the main purpose of Mitosis?

Nuclear division.

What are the four parts of Mitosis in order?

Prophase, Metaphase, Anaphase, and Telophase.

How can you identify a cell in Prophase?

The nuclear membrane is starting to disappear, DNA is in the form of chromosomes, and centrioles are starting to move apart to opposite ends.

How can you identify a cell in Metaphase?

The nuclear membrane has completely disappeared, chromosomes are lined up along the middle of the cell, and centrioles at opposite ends attach spindle fibers to centromeres.

Where do spindle fibers attach on the chromosomes during Metaphase?

They attach to the centromere.

How can you identify a cell in Anaphase?

Centrioles pull on spindle fibers causing chromosomes to separate, sending each sister chromatid to opposite ends of the cell.

How can you identify a cell in Telophase?

The cell looks like a figure 8, two nuclear membranes start reappearing, spindle fibers dissolve, and centrioles pair up in the corners.

What is Cytokinesis?

The division of the cytoplasm that produces two genetically identical daughter cells (necessary to complete division, though not part of mitosis itself).