Reproduction in protozoa

Asexual reproduction, sexual reproduction, binary fission, sporulation, plasmotomy, budding,

1. REPRODUCTION IN PROTOZOA By VYSHNAV P V M.Sc. Microbiology (2020-2022) Department of microbiology Central University of Punjab Mansa Road, Bathinda

2. WHAT IS PROTOZOA ?

3. WHAT is the Importance of protozoa? Parasitology , food chain PURPOSE OF REPRODUCTION Maintain the continuity of generation TYPE OF REPRODUCTION Sexual & asexual

4. ASEXUAL REPRODUCTION without the fusion of nucleus During favourable condition Clone Different examples are BINARY FISSION Common type Karyokinesis followed by cytokinesis Reconstruction of required materials Depending on the plane of fission binary fission is of the following types. LONGITUDINAL BINARY FISSION TRANSVERSE BINARY FISSION IRREGULAR BINARY FISSION OBLIQUE BINARY FISSION

5. LONGITUDINAL BINARY FISSION It is common in Mastigophores (e.g.: euglena cytokinesis takes place by a longitudinal furrow from the anterior end which proceeds towards the posterior end Besides the nucleus, the organelles that undergo division are blepharoplasts and chloroplasts . ' Symmetrogenic division ‘ What are Newly synthesized organelle? contractile vacuole, stigma and paraflagellar body etc.

6. TRANSVERSE BINARY FISSION Mainly seen in a ciliated organism like paramoecium Macronucleus able to controls vegetative function while Micronucleus controls reproductive function macronucleus divides by amitosis process, micronucleus divides by mitosis During cytokinesis a constriction appears in the middle of the body, by the deepening of the constriction transversely two daughter cells are formed The anterior daughter individual is called – PROTER T he posterior daughter individual is called - OPISTHE Organelle that is shared and newly appeared ?? homothetogenic binary fission

7. IRREGULAR BINARY FISSION no defined plane of fission Example: Amoeba OBLIQUE BINARY FISSION common in dinoflagellates the plane of fission is oblique to the body axis of the organism. Example : Ceratium

8. MULTIPLE FISSION OR SPORULATION Encysted animals nucleus get multiplied repeatedly Release of minute daughter nuclei Under favourable circumstances, the cyst bursts and these small animals come out common in sarcomastigophores and apicomplexans GAMOGONY : Example: plasmodium SPOROGONY It occurs following sexual fusion Motile spores are known as swarmers or swarm spores. The swarmers are of two types SCHIZOGONY OR AGAMOGONY It is an asexual reproduction method where schizonts were produced by the increased number of division in sporozoites .

9. LIFE CYCLE OF PLASMODIUM

10. PLASMOTOMY A type of asexual reproduction in which a multinucleate protozoan cell divides into two or more multinucleate daughter-cells without the occurrence of mitosis. e.g.: Opalina BUDDING daughter nuclei produced by mitotic division migrate into a cytoplasmic protrusion (bud) which is ultimately separated from the mother cell by fission monotonic budding, eg . Vorticella and multiple buds are formed in Suctorians exogenous budding eg . Ephelota endogenous budding e.g. Acineta

11. ACINETA

12. SEXUAL REPRODUCTION gametes fuse to form a new individual Able to survive unfavourable condition by creating genetic variability involves the meiotic division . SYNGAMY OR SEXUAL FUSION: complete and permanent union or fusion of two specialised protozoan unit or gametes resulting in the formation of a fertilized cell or zygote or oospore Depending upon the degree of differentiation of the fusing gametes syngamy may be of the following types

13. ISOGAMY When two fusing gametes are similar in size and shape isogamy examples are Chlamydomonas , Cryptomonas ANISOGAMY: When two fusing gametes, differ morphologically as well as in behaviour Example : Plasmodium and Volvox OOGAMY Large non-motile ga­metes are fertilized by smaller motile gametes, e.g., Plasmodium HOLOGAMY : The two ordinary mature protozoan individuals do not form gametes but themselves behave as gametes and fuse together to form a zygote. Examples are Sarcodina and Mastigophora

14. SIGNIFICANCE OF SYNGAMY: ( i ) Syngamy brings about a nuclear reorganization, and physiologically it has distinct effects (ii) It brings two previously separated lines of heredity in close association. (iii) It increases diversity among the offspring Automixis In protozoa the nucleus divides into two, the two nuclei fuse together, this is called automixis . If the two nuclei that fuse are present in a single cell, then the process is called autogamy if the two fusing nuclei are present in two different cells, then the process is known as paedogamy .

15. CONJUGATION

16. CYTOGAMY There is no nuclear exchange in cytogamy . This process resembles conjugation pellicle of the 2 individuals does not break down The early nuclear division is similar to those of conjugation ENDOMIXIS

17. HEMIXIS

18. THANK YOU