BMLT 117 CELL STRUCTURE
GROUP ASSIGNMENT-GROUP 2
PRESENTATION ON PROKARYOTES AND
EUKARYOTES.

PROKARYOTES
Prokaryotes are organisms whose cells lack a true
nucleus and membrane bound organelles.
Prokaryotes are classified into two distinct groups;
1.the bacteria(Escherichia coli, Cyanobacteria and
Streptococcus)
2.the archaeans( Thermosphaera aggregans,
Ignisphaera aggregans and Metallosphaera sedula
).

CELL STRUCTURE OF PROKARYOTES
Prokaryotes are extremely small organisms and have a relatively
simple structure. They are surrounded by plasma membrane, but have
no internal bound organelles within their cytoplasm.
The absence of a nucleus and other membrane-bound organelles
differentiates prokaryotes from the other class of organisms called
Eukaryotes
Most prokaryotes carry a small amount of genetic material in the form
of a single molecule or chromosome of circular DNA. The DNA in
prokaryotes is contained in a central area of the cell called the
nucleoid, which is surrounded by a nuclear membrane.

CHARACTERISTICS OF PROKARYOTES
 Prokaryotes are exclusively unicellular organisms.
 Prokaryotes do not have nucleus, instead their DNA
occupies an irregular-shaped area(nucleoid)
 Prokaryotes do not have membrane-bound
organelles.
 Most prokaryotes are extremophiles

Diagram of a prokaryotic cell

MODE OF REPRODUCTION IN PROKARYOTES
Prokaryotes reproduce either sexually or asexually in a
bacteria cell, sexual reproduction occurs via three
different methods; conjugation, transformation and
transduction.
Asexual reproduction in prokaryotes is only through
binary fission. Binary fission is the process by which a
bacteria cell split into two identical daughter cell.

ECONOMIC IMPORTANCE OF
PROKARYOTES
Prokaryotes are economically
important as these micro organisms
are used by humans for many
purposes. The beneficial uses of
prokaryotes include the production
of traditional foods such as yoghurt,
cheese and vinegar.

EUKARYOTES
The ‘eukaryote’ is used to describe organisms with true nucleus, where
‘eu’ means true and ‘karyon’ which means nucleus.
Eukaryotes contain membrane bound organelles and are larger and
more complex than prokaryotes. Eukaryotic cells may be classified into
two groups based on the number of cells that make an individual
organism. These are the unicellular eukaryotic cells and the multi-
cellular eukaryotic cell. Unicellular eukaryotes include the amoeba and
the euglena. Multi-cellular eukaryotes include plants, fungi and
animals.
CHARACTERISTICS OF EUKARYOTES
Eukaryotes have membrane-bound organelles and rod shape
chromosomes. Eukaryotes can reproduce either sexually or asexually.

Diagram of a eukaryotic cell

MODE OF REPRODUCTION IN EUKARYOTES.
 Eukaryotes can reproduce both asexually, through
mitosis and sexually, through meiosis and gamete
fusion.

Similarities between the prokaryotes and the
eukaryotes
 They both have a cytoplasm.
 They both contain ribosomes
 They both have cell membrane.
 They both contain DNA as the nuclear material.
DIFFEEMCES BETWEEN PROKARYOTES AND
EUKARYOTES.
 There is the absence of nuclear membrane in
the prokaryotes but eukaryotes have a nuclear
membrane.

 Prokaryotes have no membrane bound
organelles but there’s the presence of
membrane bound organelles in the
eukaryotes.
 Genetic material in the prokaryotes are made
up of a single circular DNA whiles in the
eukaryotes, genetic material is organised into
many chromosomes.
 Prokaryotes have a small ribosome and
eukaryotes have a large ribosome.
 Prokaryotes are simple small in size but
eukaryotes are complex and larger.