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Eukaryotes and Cell
Differentiation
2015/16
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What are eukaryotic cells?
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Eukaryotic cells are more complex than prokaryotic
cells. For example, prokaryotic cells such as bacteria do
not have nuclei. All animal and plant cells have nuclei
and are therefore eukaryotic. Each eukaryotic cell
contains membrane-bound cell structures called
organelles.
The organelles are found inside the cell’s cytoplasm. A
eukaryotic cell’s genetic material is contained within its
nucleus. A cell membrane surrounds a eukaryotic cell
and all its contents.
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Eukaryotic
Prokaryotic
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Eukaryotes
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The human body is made up of many
different kinds of cells.
For example, the cells that make up your brain
are very different from the cells that make up
your muscles.
Have you ever thought about how many different
kinds of cells make up your body? What makes
them different? How does the body make different
kinds of cells? Do other organisms contain different
types of cells?
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How do specialized cells form?
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Stem cells are unspecialized. One of the fundamental
properties of a stem cell is that it does not have any
tissue-specific structures that allow it to perform
specialized functions.
Stem cells are undifferentiated biological cells that can
differentiate into specialized cells and can divide (through
mitosis) to produce more stem cells
Stem cells can give rise to specialized cells. When
unspecialized stem cells give rise to specialized cells, the
process is called differentiation.
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How do specialized cells form?
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There are two broad types of stem cells:
Embryonic stem cells, which are isolated from the inner cell
mass of blastocysts, and
Adult stem cells, which are found in various body tissues
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The ability of the cell to differentiate into
different cell types (Potency)
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Totipotent stem cells can differentiate into embryonic and
extraembryonic cell types. Such cells can construct a complete,
viable organism.
Pluripotent stem cells are the descendants of totipotent cells and can
differentiate into nearly all cells, i.e. cells derived from any of the three
germ layers.
Pluripotent stem cells undergo further specialization into multipotent
progenitor cells that then give rise to functional cells. Eg.
Hematopoietic stem cells (adult stem cells) from the bone marrow
that give rise to red blood cells, white blood cells, and platelets.
Mesenchymal stem cells (adult stem cells) from the bone marrow
that give rise to variety of cell types, including: osteoblasts,
chondrocytes, myocytes and adipocytes.
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Totipotent
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Pluripotent
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