Biology - Cell Cycle & Mitosis
karyokinesis
Another name for mitosis. Means nucleus dividing.
somatic cells
Body cells.
interphase (events)
Cell is forming and carries on with its normal metabolic functions. Cell obtains nutrients, duplicates its chromatids.
mitosis (events)
Cell is replicating itself.
centromere
Connects the doubled chromosomes together.
cell cycle
Events that take place in eukaryotic cell between its formation and the moment it replicates itself.
G1/Growth 1 Phase
First stage of interphase - cell creates organelles and begins metabolism. Occurs after cytokinesis. The major period of cell growth.
prophase (events)
First stage of mitosis. DNA molecules are shortened and condensed by coiling to form visible chromosomes. Enzymes break down nuclear membrane and nucleolus. Spindle fibers form.
spindle fibers
Form during prophase. Later attach to and move chromosomes.
telophase (events)
Fourth stage of mitosis. Chromosome pairs (chromatids are pulled to opposite poles of cell). Nuclear envelope and nucleolus reform. Chromosomes uncoil. Spindle fibers disintegrate.
3 Parts of Interphase
G1 (growth 1), S phase (synthesis), G2 (growth 2)
chromatin
Genetic material during interphase. NOT clearly seen because it isn't tightly coiled.
chromatid
Genetic material located in the nucleus of the cell. Made of DNA (one coiled DNA double helix molecule). Have a long arm and a short arm.
chromosomes
Genetic material that CAN be seen once prophase begins because they are shortened and condensed by coiling.
3 Things That Form During Cell Cycle
Hair, skin, blood cells
Examples of Cells in G0 Phase
Heart muscle, eyes and brain cells.
cleavage furrow
How animal cells divide the cytoplasm. Cell membrane is constricted in the middle, then cytokinesis occurs.
cell plate
How plant cells divide the cytoplasm. Cell plate is formed in the center to divide the cytoplasm.
2 Main Phases of Cell Cycle
Interphase and Mitotic phase (M mitosis).
equator
Middle of the cell. Chromosomes line up here during metaphase.
2 Main Stages of Cell Division
Mitosis (division of nucleus) and cytokinesis (division of cytoplasm).
cell division
Mitotic (M) phase and cytokinesis (C phase) together - division of the parent (original) cell into 2 daughter (new) cells, each with the same (identical) genetic information as the parent cell.
Does mitosis occur in prokaryotic cells?
NO. If there is no nucleus, there is no mitosis.
daughter cells
Name given to the two identical cells that are created after mitosis and cytokinesis.
G0 Phase
Phase that cells enter when they exit the cell cycle (usually from G1 phase). Cells are alive and metabolically active, BUT DO NOT DIVIDE, DO NOT COPY DNA AND DO NOT PREPARE FOR CELL DIVISION. These cells cannot be replaced if they are damaged.
interphase (definition)
Phase that occurs between the times when a cell is dividing (absence of cell division). Longest phase of the cell cycle. Where most cells spend majority of lifetime.
mitosis
Process in which a eukaryotic cell separates its already duplicated chromosomes into 2 sets of chromosomes so there will be 2 identical nuclei. Occurs after the G2 phase. NUCLEUS AND NUCLEAR MATERIAL DIVIDE DURING THIS PHASE. Cytokinesis (cytoplasm division) follows.
binary fission
Process used by bacteria to divide and reproduce (no nucleus).
cytokinesis
Process whereby a single cell is divided into two identical daughter cells whenever the CYTOPLASM and cell membrane are divided.
4 Stages of Mitosis
Prophase, metaphase, anaphase, telophase.
germ cells
Reproductive cells.
S Phase/Synthesis Phase
Second stage of interphase - DNA synthesis or replication occurs - the chromosomes of the cell are copied. (Creates 2 sister chromatids). The centromere is also copied.
metaphase (events)
Second stage of mitosis. Spindle fibers attach to centromeres of chromosomes. Chromosomes align at cell's equator (middle).
G2/Growth 2 Phase
Third and final stage of interphase - Shortest phase. Cell grows in preparation for cell division (rapid growth).
anaphase (events)
Third stage of mitosis. Spindle fibers shorten and centromere splits, separating two sister chromatids.
enzymes
Used to break down nuclear membrane during prophase.
mature organism
What a fertilized cell develops into during the cell cycle.