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1 Mrs. B. SAILAJA ASHOK Zoology Senior Faculty UNIT 4 LOCOMOTION AND REPRODUCTION IN PROTOZOA (Continued from Sakshi - Vidya Page ) AMOEBOID LOCOMOTION; Energy required for the flagellar movement is obtained from ATP. Flagella exhibit undular movements, side wise lash movements and spiral gyration movements. In the beating of flagellum two phases are effective stroke and recovery stroke. Ciliary locomotion is the fastest mode of locomotion in protozoans. Ciliates are characterized by neuromotor system that coordinates the beating of cilia. Two types of ciliary beats are synchronous and metachronous movements. Gliding locomotion in flagellates, sporozoans cnidosporans and in some ciliates is brought about by myonemes. In many protozoans proteinaceous strips of pellicle cause weiggling motion called metaboly. Reproduction in protozoans:- Asexual reproduction is the common method of reproduction in protozoans. Genetic recombination does not occur in asexual reproduction. In binary fission karyokinesis is followed by cytokinesis. Binary fission is irregular in Amoeba proteus longitudinal in Euglena, transverse in Paramecium. Binary fission occurs during favourable conditions.

2 As the daughter individuals formed in the binary fission of euglena are mirror images, this fission is described as a symmetrogenic division. In Paramecium, during binary fission micro nucleus divides mitotically and macronucleus divides by amitosis. The transverse binary fission in Paramecium is called homothetogenic. Multiple fission is seen in the sarcodines and the sporozoans. Schizogony is asexual multiple fission whereas gamogony and sporogony are the multiple fissions related to sexual reproduction. Budding is common in suctorian protozoans. Plasmotomy is the division of a multinucleate protozoan into multinucleate daughter individuals by cytoplasmic division but without nuclear divisions. SEXUAL REPRODUCTION Sexual reproduction is by the fusion of pronuclei. It is either syngamy or conjugation. Conjugation occurs during unfavourable conditions, between two different mating types. In the conjugation of vorticella, It divides by longitudinal unequal binary fission to form macro and micro conjugants. Macronucleus dissolves in cytoplasm before prezygotic nuclear divisions. Cytokinesis does not occur during prezygotic nuclear divisions. The macroconjugant forms a zygote after the fusion of pronuclei. Post zygotic nuclear divisions are three series of successive mitotic divisions.

3 Series of three successive post conjugation fissions results in the formation of seven daughter individuals. Conjugation brings nuclear reorganization. Other methods of nuclear reorganization are autogamy, cytogamy and endomixis. 6. Identify the type of flagellum in monas.urceolus and polytoma in their sequential order from the following [EAMCET-2008] a.the flagellum is stichonematic b.tow or more rows of lateral appendages on the axonemes. c.the flagellum is pantacronematic. d.lateral appendages are abscent and axoneme ends as naked axial filament. 1)A B D 2)A C D 3)B A C 4)B C D Ans: 4 Practise Questions: 1) During amoeboid locomotion, protein molecules at uroid end. 1) Fold by absorbing water 3) unfold by absorbing water 2) Fold by losing water 4) unfold by losing water 2) Match the following:- I II III IV A. Monopodial i) Eliphidium 1. A C B D B. Polypodial ii) Collozoum 2. C D A B C. Reticulopodia iii) Entamoeba 3. D C A B D. Axopodia iv) Amoeba 4. C D B A 3) Number of flagella are four in 1) Euglena 2) Trichomonas 3) Giardia 4) Trypanosoma 4) Microtubules in basal body of flagellum are 1) 9 doublets + 2 singlets 2) 9 doublets only 3) 9 triplets + 2 singlets 4) 9 triplets only 5) Kinetosome is derived from 1) Nucleus 2) Blepharoplast 3) Centriole 4) Plasma membrane

4 6) In ciliates neuromotor centre is located near 1) Oral groove 2) Cytopharynx 3) Cytosome 4) Cytopyge 7) Flagella of Monas differs from the flagella of Urceolus by the absence of 1) Lateral appendages 2) Axoneme 3) Terminal naked axial filament 4) Basal body 8) Stichonematic flagella is present in 1) Astasia 2) Polytoma 3) Peranema 4) Urceolus 9) Undulating membranes are formed by 1) Pseudopodia 2) Flagella 3) Myonemes 4) Cilia 10) Flagellates move in forward direction by undulation from 1) Tip to base causing pulling forse 2) Tip to base causing pushing forse 3) Base to tip causing pushing forse 4) Base to tip causing pulling forse 11) Find out the wrong statement 1) Fastest locomotion in protozoans is ciliary locomotion 2) Pseudopodia form in the direction of advancing end. 3) In flagellar locomotion, the beating of flagellum is at right angles to the water. 4) In ciliary locomotion the movement of water is parallel to the body axis. 12) Assertion (A): Protozoans reproduce only by asexual reproduction. Reason (R): Protozoans lack gonads. 1) A and R are true, and R explains A 2) A and R are true, and R does not explain A 3) A is true and R is false 4) A is false and R is true 13) In the binary fission of Euglena, the organelles that disappear and appear newly in daughter individuals are 1) Contractile vacuole, stigma, paraflagellar body 2) Flagella, stigma, nucleus 3) Basal body, chloroplasts, nucleus 4) Stigma, basal body, vacuole 14) Find out correct pair in the following:- 1) Acineta Exogenous budding 2) Vorticella Monotomic budding 3) Ephelota Endogenous budding 4) Both 1 and 3.

5 15) Arrange the following in sequence a) Disappearance of macronuclei b) Formation of conjugants c) Disappearance of microconjugant d) Disappearance of haploid muclei in macroconjugant 1) b a c d 2) c b a d 3) b a d c 4) c a d b Key: 1) 1 2) 2 3) 2 4) 4 5) 3 6) 2 7) 3 8) 1 9) 4 10) 1 11) 4 12) 4 13) 1 14) 2 15) 3 Previous EAMCET Questions:- 1. Assertion (A): Conjugation is a temporary union between two ciliates belonging to two different mating types for the exchange and reconstitution of nuclear materials. Reason (R): Conjugation occurs between two inactive individuals which have gained their vigor and vitality due to chromosomal imbalance in their macronucleii caused by repeated amitotic division. (EAMCET 2007) 1) Both (A) and (R) are true, (R) is correct explains to (A). 2) Both (A) and (R) are true, (R) is not correct explains to (A). 3) (A) is true, (R) is false. 4) (A) is false, (R) is true. 2. Which are the sites of ATPase activity in the cilia and flagella. (EAMCET 2007) 1) Base of cilia and flagella 2) Doublets 3) Basal granules of cilia and flagella 4) Dynein arms 3. The number of daughter vorticella formed after the second series of post conjugation fission is (EAMCET 2005) 1) 7 2) 6 3) 4 4) 2 4. Folding and unfolding of actin and myosin leads to amoebic movement. This is hypothesized by. (EAMCET 2005) 1) Allen 2) Goldacre and Lorsh 3) Berthold 4) Jennings

6 5. The flagella without mastigonemes is found in (EAMCET 2004) 1) Astacea 2) Monas 3) Polytoma 4) Urceolus 6. The type of pseudopodia seen in lecithium is (EAMCET 2003) 1) Axopodia 2) Reticulopodia 3) Filopodia 4) Lobopodia 7. The flagella in Astacea is (EAMCET 2004) 1) Pantonematic 2) Acronematic 3) Pentacronematic 4) Stichonematic Key : 1) 3 2) 4 3) 1 4) 2 5) 3 6) 3 7) 4