Mitosis Flashcards
cycle of duplication and division.
Cell cycle
is a finely controlled process that results in the distribution of identical heredity material –DNA–to the daughter cells.
cell cycle
reasons why cell undergo cell division
-reproduction of the entire organism (unicellular organisms)
-growth and development, and
-tissue repair (multicellular organisms)
A cell reproduces by undergoing a coordinated sequence of events in which it duplicates its contents and then divides in two.
Mitosis
Sequential steps in cell division
-nuclear division(mitosis)
-cytoplasmic division(cytokinesis)
nuclear division
Mitosis
cytoplasmic division
Cytokinesis
the sister chromatids are pulled apart, resulting in segregation of two sets of chromosomes, one set at each end of the cell.
mitosis
the cytoplasm is divided, and two separate daughter cells are formed, each containing a single nucleus with one set of chromosomes.
cytokinesis
In plant cells, cytokinesis occurs by __________ across the parent cell’s midline.
cell plate formation
parent cell’s midline
old metaphase plate
Most of the life of a cell is spent in a non-dividing phase called _______.
Interphase
Phases in the Interphase
-first gap phase(G1)
-Synthesis (S) phase
-second gap phase (G2)
Which the newly divided cells grow
first gap phase (G1)
which the number of chromosomes is doubled and appear as chromatin.
Synthesis (S) phase
where the cell makes the enzymes and other cellular materials needed for mitosis.
second gap phase (G2)
Four stages of mitosis
-Prophase
-Metaphase
-Anaphase
-Telophase
formula for computing the average number of cell
𝑨𝒗𝒆𝒓𝒂𝒈𝒆 𝒏𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝒄𝒆𝒍𝒍𝒔 =
𝑹𝟏 + 𝑹𝟐 over 2
formula for computing the percentage of time the cell spend in mitosis.
𝑷𝒆𝒓𝒄𝒆𝒏𝒕𝒂𝒈𝒆 𝒐𝒇 𝑺𝒕𝒂𝒈𝒆 𝒐𝒇 𝑴𝒊𝒕𝒐𝒔𝒊𝒔
= (𝑻𝒐𝒕𝒂𝒍 𝑨𝒗𝒆𝒓𝒂𝒈𝒆 𝒂𝒗𝒆𝒓𝒂𝒈𝒆 𝒏𝒖𝒎𝒃𝒆𝒓 /𝒏𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝒄𝒆𝒍𝒍𝒔 𝒐𝒇 𝒄𝒆𝒍𝒍𝒔) × 𝟏𝟎𝟎
meristematic growth or zone
above the root cap
-the chromosomes that are held together by two sister
chromatids are condensed at the centromere during this stage.
-at this stage the nuclear envelope breaks down, hence the contents of the nucleus burst
out of its case and go to the cytoplasm.
prophase
the spindle fibers align the
chromosomes along the middle of the cell nucleus.
Metaphase
center line of the metaphase stage
metaphase plate
the sister chromatids have
already separated from each other then form as a new chromosome and then move to the opposite poles
of the cell.
anaphase
Chromosomes have reached
opposite poles of the cell. Spindle fibers disappear. Nuclear membrane forms around the chromosome
clusters. Chromosomes disappear from view as DNA re-extends, and nucleoli appear.
Telophase
cell divides
into two daughter cells
Cytokinesis
visible structures in the Interphase stage
the nucleolus and the nuclear
envelope.
the nuclear envelope is not visible and the
chromatids become visible which looks like a black lump of mass in the middle in a circular
shape.
Prophase stage
fibers attach to the
kinetochore looking like a lump of wires attached to the middle.
Metaphase stage
the visible structures are still the sister chromatids.
However, by this stage, they are at the opposite poles of the cell.
Anaphase stage
the visible structure seen is the forming of a new cell
membrane. They are seen as two cells with two nuclei however they still are connected.
Telophase and Cytokinesis
