This document discusses the reproduction of protozoa. It begins by defining protozoa and introducing their method of reproduction, which can occur through asexual or sexual means. Asexual reproduction methods include binary fission, multiple fission, budding, and plasmotomy. Binary fission involves mitosis followed by cytokinesis and can occur longitudinally, transversely, or obliquely. Sexual reproduction includes conjugation, where genetic material is exchanged between individuals, and syngamy, the fusion of gametes to form a zygote through processes like isogamy or anisogamy. Protozoa are also able to regenerate lost body parts.

2. PROTOZOA
protos means
‘first’
zoion means
‘animal’
• Term Protozoa was firstly introduced in 1818.
• Protozoa are eukaryotic, unicellular microorganisms,
which lack cell wall.
• Includes more than 65,000 species.

4. • A biological process by which new individual
organisms i.e. offsprings are produced from their
parent.
• Reproduction
• Protozoans reproduce by both asexual and sexual
methods.
Asexual
Sexual

5. • Binary Fission
• Plasmotomy
• Multiple Fission
• Budding
• Plasmogamy

6. • It is the division of one individual into two approximately
equal parts.
• It is the primary method of reprodution.
• This involves mitotic division of nucleus i.e. karyokinesis
which is immediately followed by cytokinesis.
• In ciliates (e.g. Paramecium), during fission, meganucleus
divides amitotically and micronucleus usually by mitotic
division.

7. • Longitudinal Binary Fission : Cytokinesis occurs along
longitudinal axis. e.g. Euglena
• Irregular Binary Fission : Cytokinesis may occurs along any
plane. e.g. Amoeba
• Transverse Binary Fission : Cytokinesis occurs along
transverse axis. e.g. Paramecium
• Oblique Binary Fission : Cytokinesis occurs along oblique
plane. e.g. Ceratium

8. • A special type of
fission in which a
multinucleate
protozoan divides
into two or more
multinucleate
daughter individuals.
e.g. Pelomyxa,
Opalinids etc.

9. In this, karyokinesis is not followed immediately by cytokinesis.
In this, firstly the nucleus undergoes a series of divisions, results
into a number of daughter nucleus, which usually arrange
themselves at the periphery.
Later the body cytoplasm
divides into as many parts
as there are daughter nuclei,
resulting into formation of
several daughter
individuals.
Example : Plasmodium,
Aggregata

10. Schizogony : Formation of numerous daughter nuclei is
followed by the formation of cytoplasmic buds, each contains
a nucleus.
e.g. Plasmodium

11. • In this, new organisms develop from an outgrowth or bud.
• It is a modified form of fission.
• When a parental body produce only one bud, it is known as
monotomic. e.g. Vorticella
• When a parental body produce several buds simultaneously, called as
multiple budding. e.g. Ephelota

12. • A type of reproduction in which the cytoplasm of two or
more parent cells fuse together without the fusion of
nuclei.
• After separation they remain unchanged.
• It usually serves for the purpose of digestion of large prey.

13. • Syngamy
• Conjugation

14. • Fusion of two gametes resulting in the formation of zygote.
• Fused nucleus of zygote is called as synkaryon.
Types :
(a)Hologamy : Type of syngamy in which
the two premature protozaon individuals
do not form gametes, but themselves
behave as gametes and fuse together to
form a zygote. e.g. Copromonas
(b) Isogamy : When two fusing gametes
are morphologically similar but differ in
behaviour, they are called as isogametes and
their union is called as isogamy.
Isogametes are generally produced by
multiple fission.
e.g. Chlamydomonas, Monocystis

15. (c) Anisogamy : When two fusing
gametes are differ in morphology as
well as in behaviour, they are called
as anisogamy and their union is
anisogamy.
• Usually small or motile gametes are
male or microgametes and large
non-motile ones are the female or
macrogametes.
e.g. Plasmodium, Volvox
(d) Autogamy : It involves the
fusion of gametes derived from the
same parent cell.
e.g. Actinophrys & Actinosphaerium

16. • Also called amphimixis.
• Firstly discovered by
Joshua Laderberg and
Edward Tatum in 1946.
• It is the temporary union
of two individuals where
exchange of genetic
materials take place by
direct cell-to-cell contact.
• Conjugation takes place
only between same groups
of individuals.
• Organisms which take part
in conjugation is called as
conjugants.

17. CONJUGATION

18. • A mode of asexual reproduction in which offsprings are produced
from an unfertilized egg.
e.g. Chlamydomonas, Actinophrys
A process by which
some organisms can
restore the lost or
amputated parts of
their body.
Most of the
protozoans can
regenerate their lost
body parts.

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