Cells (Mitosis)
23.02.21
- Mitosis is a process where a single cell divides into two identical daughter cells (cell division).
During mitosis one cell divides once to form two identical cells. The major purpose of mitosis is for
growth and to replace worn out cells
Cell Cycle:
- Interphase
➔ The longest part of the cell cycle
➔ This is when the cell grows and copies its DNA
before mitosis
➔ G1 Phase; First gap phase, the cell grows larger
and organelles are copied
➔ S Phase; Synthesis phase; the cell synthesizes a
complete cop of the DNA in its nucleus
➔ G2 Phase; The cell grows more, makes proteins
and organelles and begins to reorganize in
preparation for mitosis.
- Mitosis
➔ The cell divides its previously-copied DNA and cytoplasm to make new identical daughter cells.
➔ Prophase
◆ The nucleolus disappears
◆ Chromatin condenses into chromosomes and
becomes visible
◆ Nuclear membrane disappears
◆ Centrosome divides in two, moves to opposite side of
the cell
◆ Centrosomes then begin generating microtubules
(spindle fibers)
➔ Metaphase
◆ The spindle has captured all the chromosomes and
lined them up at the (equator) middle of the cell,
ready to divide
➔ Anaphase
◆ Centromere divides
◆ Sister chromatids separate from each other and are
pulled towards opposite ends of the cell
◆ The protein ‘glue’ that holds the sister chromatids
together is broken down, allowing them to separate.
◆ Each is now its own chromosome one
23.02.21
- Mitosis is a process where a single cell divides into two identical daughter cells (cell division).
During mitosis one cell divides once to form two identical cells. The major purpose of mitosis is for
growth and to replace worn out cells
Cell Cycle:
- Interphase
➔ The longest part of the cell cycle
➔ This is when the cell grows and copies its DNA
before mitosis
➔ G1 Phase; First gap phase, the cell grows larger
and organelles are copied
➔ S Phase; Synthesis phase; the cell synthesizes a
complete cop of the DNA in its nucleus
➔ G2 Phase; The cell grows more, makes proteins
and organelles and begins to reorganize in
preparation for mitosis.
- Mitosis
➔ The cell divides its previously-copied DNA and cytoplasm to make new identical daughter cells.
➔ Prophase
◆ The nucleolus disappears
◆ Chromatin condenses into chromosomes and
becomes visible
◆ Nuclear membrane disappears
◆ Centrosome divides in two, moves to opposite side of
the cell
◆ Centrosomes then begin generating microtubules
(spindle fibers)
➔ Metaphase
◆ The spindle has captured all the chromosomes and
lined them up at the (equator) middle of the cell,
ready to divide
➔ Anaphase
◆ Centromere divides
◆ Sister chromatids separate from each other and are
pulled towards opposite ends of the cell
◆ The protein ‘glue’ that holds the sister chromatids
together is broken down, allowing them to separate.
◆ Each is now its own chromosome one
