How is prokaryotic cell different from eukaryotic cell?
Prokaryotic cells are organisms that lack a membrane-bound nucleus and
other membrane-bound organelles. They are usually smaller in size and
simpler in structure than eukaryotic cells. Prokaryotes are divided into two
domains: Bacteria and Archaea.
One of the main differences between prokaryotic and eukaryotic cells is the
presence of a membrane-bound nucleus. In eukaryotic cells, DNA is found in
the nucleus while in prokaryotic cells it is found in the nucleoid region of the
cytoplasm. The DNA of prokaryotic cells is usually circular and not associated
with histone proteins while eukaryotic DNA is linear and bound to histone
proteins.
Prokaryotic cells are also distinct from eukaryotic cells in the absence of
membrane-bound organelles such as mitochondria, endoplasmic reticulum,
and Golgi bodies. Instead, they have simpler structures like ribosomes,
cytoplasm, plasma membrane, and cell wall. Prokaryotes also do not have a
cytoskeleton to provide internal structure and support as in eukaryotic cells.
The processes of cell division in prokaryotes occur via binary fission, which
results in the division of one parental cell into two identical daughter cells.
Eukaryotic cell division, on the other hand, involves mitotic division in somatic
cells or meiosis during the formation of reproductive cells.
All living organisms are either prokaryotes or eukaryotes, and this distinction
has important consequences in terms of ecological niches, the evolution of
multicellularity, and the diversity of life on Earth.
In conclusion, prokaryotic cells are structurally different from eukaryotic cells
due to the absence of a distinct nucleus and membrane-bound organelles.
Their simplicity and small size have made them dominant organisms on Earth
that play important roles in biogeochemical cycles, symbiotic relationships,
and human health.
References:
1. Alberts, B. et al. (2014). Molecular Biology of the Cell. 6th edition. Garland Science.
2. Campbell, N. A. and Reece, J. B. (2005). Biology. 7th edition. Pearson Education, Inc.
3. Tortora, G. J. et al. (2011). Microbiology: An Introduction. 11th edition. Pearson
Education, Inc.