Cell Cycle, Mitosis, & Meiosis Flashcards
What is the cell cycle?
It describes the cell’s life as it goes through phases of division.
What are the three parts that the cell cycle can be divided into?
Resting Phase (G0)
Interphase (G1, S, G2)
Cell Division (P,M,A,T)
What is the Gap 0 (G0) phase?
It is the resting phase. The cell does not participate in cell division during this phase.
What is mitosis?
Asexual reproduction of cells.
What is Interphase?
It is the phase when a cell prepares for divison. Roughly takes up about 90% of the time in the cell cycle. This is where growth and DNA Replication occurs.
What happens during the Gap 1 (G1), Synthesis (S), and Gap 2 (G2) phase?
G1 = growth
S = DNA replication
G2 = more growth
What happens in the G1 checkpoint (restriction point)?
At this checkpoint is when a cell commits to division. The presence of DNA damage or other external factors can cause a cell to fail this checkpoint and not divide.
What happens in the G2 checkpoint?
This checkpoint takes place before cell division and checks for DNA damage after DNA replication. If damage is detected, it “pauses” cell division until the damage is repaired.
What happens in Mitosis?
Cell division.
What are the four stages of Mitosis?
Prophase
Metaphase
Anaphase
Telophase + cytokinesis
What happens in Prophase?
The cell is prepared to go through mitosis. It involves condensing the DNA such that distinct chromosomes become visible as sister chromatids. The nuclear envelope and nucleolus disappear and the mitotic spindle and kinetochore forms.
What happens in Metaphase?
Chromosomes line up at the middle of the cell along the imaginary line, called the metaphase plate. Also has the final checkpoint. The cell checks to make sure that the kinetochores are attached properly to the microtubules of the mitotic spindle. This prevents improper separation which can lead to nondisjunction.
What happens in Anaphase?
Sister chromatids are separated and pulled to opposite sides of the cell by shortening the microtubules.
What happens in Telophase + cytokinesis?
The new nuclear envelope and nucleolus appears around each set of chromosomes. Finally, cytokinesis occurs and separates the cell into two daughter cells.
What is Meiosis?
It is the form of cell division essential for sexual reproduction and takes place in germ cells (sex cells)