Cell Division
What is Cell Division used for?
2. Growth of multicellular organisms
3. Repair and Replacement of cells
4. Production of Sperm and Eggs
What are the 2 stages of the cell cycle and their phases?
Interphase: G1, S, G2
Mitotic Phase: Mitosis and Cytokinesis
Mitotic Spindle is fully formed and chromosome is aligned.
Metaphase
What is the difference between Anchorage Dependence and Density-Dependent Inhibition?
Anchorage Dependence- the need for cells to be in contact with a solid surface to divide.
Density-Dependent Inhibition- crowded cells stops dividing
What is purpose of the checkpoints within the cell cycle control system?
- Prevents over growth of cells
- stops an event if necessary
- Signal an events to proceed
How long does it take for Binary Fission to occur?
Where can you find Binary Fission?
20 minutes
Prokaryotes
When does duplication of the cell occur and DNA synthesize?
S phase of Interphase
Mitotic spindles grows out from centromeres and the Nuclear Envelope breaks into fragments and disappears.
Prophase
What is cell division controlled by?
1. Anchorage Dependence
2. Density-Dependent Inhibition
3. The Presence of essential nutrients
4. Growth Factors
Makes sure sister chromatids are correctly attached to the spindle microtubules.
M Checkpoint
What are 3 diffenreces between Prokaryotic chromosomes and Eukaryotic chromosomes?
Prokaryotes:
- Not enclosed in a nucleaus
- Singular circular DNA molecule
- Much Smaller
Eukaryotes:
- Enclosed in a nucleus
- Multiple Strands of Chromosomes
- More Complex and Larger
Mitosis is the division of _____, whereas Cytokinesis is the division of_____
Nucleus and Cytoplasm
Spindle microtubules doesn't attach to the chromosomes. Separates the poles resulting in a equal collection of chromosomes.
Anaphase
If a cell continues to grow over its limit it will result to cancer. In what part of the cell cycle does this describe?
Density-Dependent Inhibition
If a cell never passes the G1 checkpoint, it will never divide. What phase of the check points will the cell enter in?
G0 Phase
How do the sister chromatids result to daughter cells?
In other words:
When a cell divides, what happens to the sister chromatids?
They separate from each other and becomes chromosomes which then the chromosomes is separated and sorted into separate daughter cells.
What is the difference between G1 and G2 phases?
G1- growth, increase in cytoplasm
G2- growth, preparation for division
The cells continues to elongate with chromatin uncoiling dividing into 2 daughter cells
Telophase and Cytokinesis
In growth factors, what does proteins stimulate?
Division
_____Ensures cells do not initiate mitosis before they have a chance to repair the damage DNA after replication to begin apoptosis, whereas _______checks for cell damage, growth factors, nutrients, etc.
G2 Checkpoint
G1 Checkpoint
What are the 3 stages of Binary Fission?
1. Duplication of the chromosome and seperation of the copies
2. Continued elongation of the cell and movement of the copies
3. Division into 2 daughter cells
During Interphase:
What happens to the cytoplasmic contents?
How many centrosomes forms?
When chromosomes duplicate what does it form?
They double
2
Sister Chromatids
____usually forms near the cell equator from microfilaments causing a separation of the plasma membrane form 2 separate cells, whereas _____forms a cell wall in the equator that grows outward to reach the edges.
Cleavage Furrow
Cell Plate
In the presence of essential nutrients is important because?...
If you do not eat, then you will not grow healthy.
Write the sequence of the Cell Cycle, Checkpoints, and PMAT in order from start to end.
G0, Interphase, G1, S, G2, Mitosis, Prophase, Metaphase, Anaphase, Telophase/ Cytokinesis