The Cell Cycle Flashcards
Name the phases of the cell cycle
G1, S , G2, M, G0 (only sometimes)
What happens in the G1 phase of the cell cycle
Prep for S phase
What happens in the S phase of the cell cycle
DNA synthesis when the chromosomes are duplicated in DNA replication
What happens in the G2 phase of the cell cycle
- cells with duplicated chromosome are held together at the centromere
- another prep phase, duplicate organelles and increase cytoplasm
What happens in the M phase of the cell cycle
- cell division
- nuclear division
What happens in the G0 phase of the cell cycle
Resting phase, no division is taking place
Which of the phases does interphase consist of?
G1, S, G2
What happens in prophase?
- chromosomes condense
- centrosomes move to opposite poles
- mitotic spindle forms
What happens in prometaphase?
- Breakdown of the nuclear envelope
- chromosomes attach to the mitotic spindle
What happens in metaphase?
- centrosomes are at opposite poles
- chromosomes are at their most condensed
- chromosomes line up at the equator or the mitotic spindle
What happens in anaphase?
- sister chromatids separate synchronously, each new daughter cell moves to the opposite spindle pole
What happens in telophase?
- Chromosomes arrive at the spindle poles
- chromosomes decondense
- nuclear envelope reforms
What happens in cytokinesis?
Actin and myosin accumulates between the poles of the mitotic spindle beneath the plasma membrane. The ring contracts and forms an indentation or cleavage furrow, which divides the cell into two new rings
What is a metaphase plate?
A cross section plane along which the chromosomes are lined up down the centre of the cells in metaphase
What are the three types of spindle microtubules?
Astral , kinetochore, interpolar
What is the function of the astral microtubules?
Orientation and positioning of the spindle inside the cell (also influences the site of cytokinesis)
What is the function of kinetochore microtubules?
They project from the centrosome and connect with the kinetochore
What is the function of the interpolar microtubules?
They extend from the poles and interact in the middle of the zone of interdigitation
What is a mitotic spindle?
A microtubule machine that separates the duplicated chromosomes