(Module 2)Cell Divison and Stem Cells Flashcards
Why do cells divide
To grow bigger to repair and to replace dead or dying cells.
What is the first stage of the cell cycle
Interphase (G1, S and G2)
What is the second stage of the cell cycle
Mphase (Mitosis and Cytokinesis)
What happens in the first stage of cell division
Cell prepares to divide:
G1: Cell grows and new organelles and proteins are made
S: DNA synthesis. This is when the cell’s DNA is replicated
G2: Cell keeps growing
What happens in cell mitosis
(DNA is arranged into 46 chromosomes)
Chromosomes become shorter and thicker
Chromosomes line up alongside the centre of the cell
Chromosomes get pulled to opposite ends (opposite poles) of the cell.
What happens in cytokinesis
Cytoplasm divides to produce 2 genetically identical cells
The cell cycle summarised
G1 - Growth
S - DNA syntheis
G2 - Growth and preparation for Mitosis
Mitosis - Cell division
What is a chromosome
A chromosome is the part of the cell which carries genes
What is a gene
Genes are a small packet of information that controls a characteristic
What is a stem cell
This is a undifferentiated cell of an organism which is capable of:
Making copies of each other
Or differentiate to form different cell types
What are the two types of stem cell
Embryonic stem cells
Adult stem cells
What are embryonic stem cells
From IVF embryos - they can be cloned and can become differentiated into many types of cells
What are the problems with adult stem cells
They can only become different types of blood cells
How were stem cells researched
Used to treat paralysis in rats and diabetes
What are the stem cells in plants
In the meristem- where the plant grows - stem and roots
