Mjtosis Flashcards
What is the cell cycle?
Cell cycle is a repeating cycle of events in the cells life. Consists of 2 main stages, interphase and mitosis (cytokinesis)
What is meiosis
To produce reproductive cells, sperm or ovum.
Explain interphase
Interphase is where the cell grows gains nutrients and prepares for division, made up of 3 stages. G1, S, G2
Cells spend 90% KF their life in interphase, they take in nutrients grow and replicate DNA
Explain G1, S, G2
G1 - first growth phase, cell grows and produces new proteins and organelles
S - synthesis phase , cell replicated DNA
G2 - cell produces the organelles and structures needed for-cell division
Goal of mitosis?
When cell divides to have 1 complete copy of genetic material from the cell, to have 2 identical daughter cells
What happens in the prophase?
The uncoiled chromatin condenses into sister chromatids. The nuclear membrane disintegrates, spindle fibers appear and centriols appear at opposite poles.
What happends in metaphase
Spindle fibres attach to centromeres and sister chromotjds line up in middle of cell
Anaphase
Sister chromotjds get pulled apart by centromere to opposite side of cell by spindle fibers
Telophase
Spindle fibres break down, 2 nuclei start to form, nuclear membrane comes back, chromosomes turn into chromatin again. Cell divides into 2, called cytokinesis
What is a cleavage furrow
A cleavage furrow is cytokinesis in an animal cell, it’s what happends when cells divide into 2. It pinches inwards
How do plant cells divide
Since plant cells have a cell wall which is rigid and can not bend, they form cell plates to divide with vesicles which are fused in the cell wall.
Necrosis
Cell dies due to external factors
What’s apoptosis
Regulated cell death. Eg white blood cells r removed after fighting infections
