Mitosis Flashcards
What s Mitosis?
Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus (identical), typical of ordinary tissue growth. Gametes (sex cells) do not undergo mitosis.
Why is mitosis important for the body?
Important for growth and development
Repairs damaged tissues/cells and replaced worn out cells by making more cells
What are the effects of cells undergoing mitosis more than interphase?
There would be uncontrolled rapid growth leading to cancer. In the cell cycle, cells spend 10% in mitosis and 90% in interphase.
What is interphase?
Interphase is the phase of the cell cycle in which a typical cell spends most of its life (90%). It is the ‘daily living’ or metabolic phase of the cell, in which the cell obtains nutrients and metabolizes them, grows, reads its DNA, and conducts other “normal” cell functions. DNA replication takes place here.
What happens during interphase?
During interphase, cellular organelles double in number, the DNA replicates, and protein synthesis occurs. The chromosomes are not visible and the DNA appears as uncoiled chromatin.
What does mitosis start and end with?
Mitosis starts and ends with diploid cells. In humans there should be 46 chromosomes in each chromosome after mitosis. Diploid cells are cells with two sets of chromosomes. Sexually reproducing organisms are diploid (having two sets of chromosomes, one from each parent).
What are the Mitotic Stages?
PMAT Prophase: pro = before Metaphase: m = middle Anaphase: a = away Telophase = two
Prophase (P)
The chromosomes are condensing (they’re thickening and becoming visible) making them easier to pull apart later on. The nucleus disassembles.
Metaphase (M)
The chromosomes line up the middle of the cell.
Anaphase (A)
The sister chromatids separate from each other and are pulled towards opposite sides of the cell (to the centriole) via the spindle fibres (which are connected to the centromere and chromosome arms.
Telophase (T)
The chromosomes are right at complete opposite sides
and new nuclei (two) are forming on each side surrounding the chromosomes to make the two new cells. Nuclei membrane and nucleoli reappear
Cytokinesis
Overlaps with telophase. The division of the cytoplasm. The cell membrane constricts in the centre of the cell, forming a narrow area of cytoplasm, which consequently breaks forming two cells.
Centromere
The part of the chromosome where sister chromatids are held together.
Chromatids
strands of replicated DNA (one half of a chromosome)
Centrioles
Each of a pair of minute cylindrical organelles near the nucleus in animal cells, involved in the development of spindle fibres in cell division.
