The Cell Cycle
As eukaryotic cells grow and divide, they move through three distinct stages.
These stages make up what is known as the cell cycle. The stages
of the cell cycle are interphase, mitosis, and cytokinesis. Cells grow and
prepare to divide during interphase. Cell division occurs during mitosis and
cytokinesis.
As eukaryotic cells grow and divide, they move through three distinct stages.
These stages make up what is known as the cell cycle. The stages
of the cell cycle are interphase, mitosis, and cytokinesis. Cells grow and
prepare to divide during interphase. Cell division occurs during mitosis and
cytokinesis.
Interphase
Interphase is the longest stage for most cells, but it is not a resting stage. During interphase, the cell is carrying out all life activities except division.
These activities include growth, cellular respiration, and any specialized functions of that cell type. During this stage, the genetic material, DNA
, is in very long, thin, invisible strands. When the cell prepares for cell division, the strands are duplicated so that there are two
identical strands of the genetic material. More organelles are also formed.
Interphase is the longest stage for most cells, but it is not a resting stage. During interphase, the cell is carrying out all life activities except division.
These activities include growth, cellular respiration, and any specialized functions of that cell type. During this stage, the genetic material, DNA
, is in very long, thin, invisible strands. When the cell prepares for cell division, the strands are duplicated so that there are two
identical strands of the genetic material. More organelles are also formed.
Cell Division
Cell division occurs in two stages: mitosis the division of the contents of the nucleus and cytokines is the division of the rest of the cell, such as cytoplasm, organelles, and cell membrane. Each cell division produces two genetically identical cells called daughter cells. Mitosis is composed of four phases: prophase, metaphase, anaphase, and telophase. The cells move gradually from one phase to the next.
Cell division occurs in two stages: mitosis the division of the contents of the nucleus and cytokines is the division of the rest of the cell, such as cytoplasm, organelles, and cell membrane. Each cell division produces two genetically identical cells called daughter cells. Mitosis is composed of four phases: prophase, metaphase, anaphase, and telophase. The cells move gradually from one phase to the next.
Prophase
As interphase ends, the cell enters the first phase of mitosis—prophase. The long strands of DNA condense into a compact form, becoming visible under a microscope as chromosomes. Because the DNA was copied during interphase, each chromosome consists of two identical strands called sister chromatids. An individual strand is called a chromatid. The sister chromatids are held together by a centromere. The nuclear membrane
dissolves during prophase.
As interphase ends, the cell enters the first phase of mitosis—prophase. The long strands of DNA condense into a compact form, becoming visible under a microscope as chromosomes. Because the DNA was copied during interphase, each chromosome consists of two identical strands called sister chromatids. An individual strand is called a chromatid. The sister chromatids are held together by a centromere. The nuclear membrane
dissolves during prophase.
Metaphase
During metaphase, the chromosomes line up in the middle of the cell. This stage is easily recognized. All the chromosomes must be in the line for mitosis to continue.
During metaphase, the chromosomes line up in the middle of the cell. This stage is easily recognized. All the chromosomes must be in the line for mitosis to continue.
Anaphase
In anaphase, the centromere splits and the sister chromatids separate. They are now called “daughter chromosomes.” These daughter chromosomes move to opposite sides of the cell.
Telophase
The daughter chromosomes stretch out, become thinner, and are no longer visible. A new
nuclear membrane forms around each group of daughter chromosomes. At
this stage, the cell appears to have two nuclei.
The daughter chromosomes stretch out, become thinner, and are no longer visible. A new
nuclear membrane forms around each group of daughter chromosomes. At
this stage, the cell appears to have two nuclei.
Cytokinesis
Cytokinesis is the final stage of cell division. The cytoplasm divides,
producing two genetically identical daughter cells. Th e process of cytokinesis
is slightly different in plant and animal cells. In a plant cell, a plate between
the daughter cells develops into a new cell wall (a). In an animal
cell, the cell membrane is pinched off in the centre (b).
Cytokinesis is the final stage of cell division. The cytoplasm divides,
producing two genetically identical daughter cells. Th e process of cytokinesis
is slightly different in plant and animal cells. In a plant cell, a plate between
the daughter cells develops into a new cell wall (a). In an animal
cell, the cell membrane is pinched off in the centre (b).
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Pick up line "you're like telophase, I admire your cleavage."
Pick up line "you're like telophase, I admire your cleavage."