Mara Bessinger - Unit #2: The Cell Cycle and Mitosis Flashcards
What are the two reasons why cells have to divide?
DNA overload
The cell has more trouble moving items across the cell membrane
Define DNA overload
The larger a cell becomes, the more demands the cell places on its DNA.
Explain what happens to the surface and volume ratio as a cell enlarges.
It decreases
Cell division occurs in two main stages. What are they?
Mitosis and interphase
What is the cell cycle?
Series of events that take place as the cell grows and divides.
Name the stages of the cell cycle in order.
G1, S, G2, m phase
What happens in the G1 phase?
Cells grow and new organelles are produced
What happens in the S phase?
DNA replicates and chromosomes are copied
What happens in the G2 phase?
Organelles and molecules required for cell division are produced
What are the 4 stages of mitosis in order?
Prophase
metaphase
anaphase
telophase
What is the G0 stage?
stage where cells never divide. (ex. Neurons, red blood, cardiac, sperm, egg))
What phases does interphase include?
G1, S, G2
What happens in prophase
nuclear envelope disappears, the first visible sign of cell division as well as the longest phase of mitosis.
What happens in metaphase?
shortest phase, chromosomes line up in the middle of the cell.
What happens in anaphase?
chromosomes pull apart and spindle fibers shorten
What happens in telophase?
final phase, cell separates into two identical daughter cells
