CELL DIVISION (MITOSIS)
Introduction:
Somatic or body cells divide at the end of a process called the cell cycle. During the cell
cycle there is a division of replicated or doubled chromosomes (karyokinesis) and a
division of the cytoplasm or non-chromosome parts of the cell (cytokinesis). The
function of the cell cycle is to build an exact copy of each chromosome and then
distribute an identical set of chromosomes to each of the two daughter cells.
During a part of the cell cycle called interphase each chromosome replicates or doubles,
making an exact copy of itself. This doubling produces a chromosome with two identical
strands that are attached to a common centromere.
During a part of the cell cycle called mitosis chromosome movements are continuous, but
four distinct phases are easily recognized: prophase, metaphase, anaphase and
telophase.
In this exercise, you will observe and identify the various phases of the cell cycle in plant
and animal cells. You may want to use your text as a reference.
Events of the Life Cycle
INTERPHASE Replication or doubling of chromosomes.
A spherical nucleus is visible.
PROPHASE Chromosomes become condensed and visible in the light
microscope as sister chromatids. Spindle fibers appear and the
nucleus, nucleolus and nuclear membrane, disappears.
METAPHASE Chromosomes line up on the equator or center of the cell.
Centromeres attach to the spindle fibers.
ANAPHASE The chromatids separate at the centromere and move to the poles or
ends of the cell.
TELOPHASE The chromatids are at the poles. The chromatids uncoil and become
less and less visible in the light microscope. The spindle fibers
disappear and the nucleus reappears, including the nucleolus and
the nuclear membrane.
CYTOKINESIS Division of the cytoplasm of the cell. In a plant cell, a cell wall is
formed. In an animal cell, the cell furrows at the outer edges of the
cell and cleaves the cell in two.
52010 Cell Division (Mitosis) Lab 12-1
Introduction:
Somatic or body cells divide at the end of a process called the cell cycle. During the cell
cycle there is a division of replicated or doubled chromosomes (karyokinesis) and a
division of the cytoplasm or non-chromosome parts of the cell (cytokinesis). The
function of the cell cycle is to build an exact copy of each chromosome and then
distribute an identical set of chromosomes to each of the two daughter cells.
During a part of the cell cycle called interphase each chromosome replicates or doubles,
making an exact copy of itself. This doubling produces a chromosome with two identical
strands that are attached to a common centromere.
During a part of the cell cycle called mitosis chromosome movements are continuous, but
four distinct phases are easily recognized: prophase, metaphase, anaphase and
telophase.
In this exercise, you will observe and identify the various phases of the cell cycle in plant
and animal cells. You may want to use your text as a reference.
Events of the Life Cycle
INTERPHASE Replication or doubling of chromosomes.
A spherical nucleus is visible.
PROPHASE Chromosomes become condensed and visible in the light
microscope as sister chromatids. Spindle fibers appear and the
nucleus, nucleolus and nuclear membrane, disappears.
METAPHASE Chromosomes line up on the equator or center of the cell.
Centromeres attach to the spindle fibers.
ANAPHASE The chromatids separate at the centromere and move to the poles or
ends of the cell.
TELOPHASE The chromatids are at the poles. The chromatids uncoil and become
less and less visible in the light microscope. The spindle fibers
disappear and the nucleus reappears, including the nucleolus and
the nuclear membrane.
CYTOKINESIS Division of the cytoplasm of the cell. In a plant cell, a cell wall is
formed. In an animal cell, the cell furrows at the outer edges of the
cell and cleaves the cell in two.
52010 Cell Division (Mitosis) Lab 12-1
