biology notes class

MECANISM OF DNA REPLICATION   -Dna replication occurs in the s-phase of inerphase of cell cycle due to which the amount of dna is dooble. -Replication of dna is a complex multistep process with each sky precisely controlled by a specific enzyme.many protein factor and ions are required for replication. ORIGIN OF REPLICATION;- -The origin of replication or ori is of a particular region of dna having a specific sequence of nucleo tides called autonomic replicating sequence. -Prokaryotic dna has a single replicon while eukaryotic dna has hundreds and thousnds of replicons. -Repucation proceeds on both sides from the ori site which is called bidirection replication. ACTIONVATION OF NULEOTIDES;- -The four types of deoxyribonucleotides required for dna replication are DEMP,DGMP,DTMP and DCMP. -These nucleotictes added phosphoric acid with the help of energy and phosphorylase to produce triphosphate state and water. UNWINDING OF HELIX:- -Unwinding of dna helix at t...

Development of frog  - In frog sex are separate with will develop sexual dimorphism. - Male has a testis and female has a pair of ovary. -During breeding season male Copulation and female compilations is called amphexsus. -Frog and ovary and female egg in water fertilization is external and development is direct and the larva called tadpole. Fertilization -It is monosperming only one spore fussed with egg fertilized rotated such a way that the animal hemisphere those above. -The jelly coat swells and increase in thikness 2nd mitotic division completed resulting in the release of  second polar. -Spawn enter in the egg the vitaline  member become  elevated and called as fertilization membrane. -Immediately after fertilization the black pigment animal pole placed above label vegital pole below. i -Before release of egg in water Jelly court in think and observed water and going to swell -The entire of sporm causes the movement of the pigment on one side just b...

                            SPERMATOGENESIS -The process by which sperms are from inside the testes is called spermatogenesis. -The tratarmation of the spermatid into spermatozoon spermis called spermatogenesis . -Spermatogenesis can be completed in 2phases-formation of spermatids and sperogenesis FARMATION OF SPERMATIDS -The formation of formatids fromgerminal epithelial cells can take place in the following 3 phases;- MULTIPLICATION PHASE;- -The primodial germ cells contain large sites and choromatin nucleous. -It divided rippitedly by reppited mitotic division and chromatin nucleous . -This cells have 2n cells of chromosome. GROTH PHASE;- -Are the end of multiplication phase the spermato gonia increase in size by accumulation of nutrient from the nourishing cells and also by the synthetic prot and nucleic acid. -The enlarged diploid cell...

                                       DECLARATION I do here by declare that the dissertation entitled “DISCOVERY OF FISHES OF GOPALPURCOAST” submitted to NILAMADHABA MAHAVIDYALAYA COLLEGE, KANTILO in partial fulfilment of the requirement of B.Sc. in Zoology is the outcome of the research work carried out by me under the guidance of   Mr Soraj Kumar Mishra, Lecturer Department of Zoology, NILAMADHABA MAHAVIDYALAYA COLLEGE KANTILO. The dissertation in an authentic record of investigation and has not been presented in any other degree of distinction of this or any other university. DATE:                                  ...