Mitosis

Cell Cycle

• Just like many other organisms cells have different stages in their life

• A cell has many different stages during its lifetime

• The cell cycle is the description of the different phases in the life cycle of a cell

Cell Cycle

• Cells have 4 distinct and different phases1. G1 Phase

Cell Growth2. S Phase

DNA Replication3. G2 Phase

Prep for mitosis4. M Phase

Cell Division

Cell Cycle

• Not all of the phases take the same amount of time!• Different phases take different amounts of time

Cell Cycle

• The M Phase has 4 distinct parts– Prophase– Metaphase– Anaphase– Telophase

• An easy way to remember this are the letters PMAT

Interphase

• Every stage of the cell cycle that is not part of cell division is part of interphase

• This includes the G1, S, G2 phases

Interphase In Flipbook1) Normal cell functions and normal metabolic roles.2) DNA Replication

Prophase

• First and longest phase– 50 – 60 Percent of Mitosis

• 1) When Chromosomes become visible for the first time

• 2) Two centrioles appear and move to opposite sides of the nucleus

• 3) The nuclear envelope breaks down

Prophase

• Spindles are long thin fibers that form in the cytoskeleton

• Tiny structures that help to organize the spindles

• They attach to the centromeres of the chromosomes during prophase

Prophase in Flipbook

• 1) When chromosomes become visible for the first time• 2) Two centrioles appear and move to opposite sides of the nucleus• 3) The nuclear envelope breaks down

Metaphase

• Very short, can last only minutes

• The chromosomes line up across the center of the cell

• The spindle fibers connect to the centromeres of each chromosome to the poles of the spindle

Metaphase in Flipbook• 1) The chromosomes start to migrate to the center of the cell• 2) The chromosomes line up across the center of the cell• 3) The spindle fibers connect to the centromere of each

chromosome to the poles of the spindle

Anaphase

• 1)The centromeres that join the sister chromatids separate

• 2) The chromosomes continue to separate until they are positioned near the poles of the cell

• 3) Anaphase ends when the chromosomes stop moving

Anaphase in Flipbook

1)The centromeres that join the sister chromatids separate2) The chromosomes continue to separate until they are positioned

near the poles of the cell3) Anaphase ends when the chromosomes stop moving

Telophase

• 1) The condensed chromosomes start to unravel

• 2) Nuclear envelopes start to reform around each cluster of chromosomes

• 3) The spindles begin to break apart

Telophase in Flipbook

• 1) The condensed chromosomes start to unravel• 2) Nuclear envelopes start to reform around each cluster of

chromosomes• 3) The spindles begin to break apart

Cytokinesis

• Once two distinct nuclei have formed, cytokinesis will occur

• Cytokinesis is the division of the cytoplasm

Cytokinesis

• The cell membrane is drawn inward until the cytoplasm is pinched into two equal parts

• Each cell retains the cytoplasm, nucleus and organelles inside of its membrane

Cytokinesis

• In plants, a structure known as a cell plate forms

• The cell plate forms midway between the two plant cells

• It gradually pushes the plant cells apart

• The cell plate then forms in the cell wall

Cytokinesis in Flipbook

• Cytokinesis is the division of the cytoplasm

Animations

• Mitosis