Zoology concept

what is the zoology
                                 Zoology or animal biology is the branch of biology.that is the related to kingdom ,including structure  embryology evolution  habitat and distribution of all animal and living organism.   Zoo i.e animal a and logos i.e knowledge or study.
                                    It deal with both animal and extinct organism.Zoology is derived  from the Greek word Zoon ( animal)+ logos(study).Zoologies studies everything  including structure habitat evolution embryology etc.


 Mitochondria
                        the mitochondria is a double membrane bound organelle found in most eukaryote cells.the word mitochondria comes to from the Greek mito that is 'thread' and chondria that is granule or gram like.
                       mitochondria are commonly between 0.75 and 3µm in diameter but very considerable in size and structure.unless specifically stained, thy are not visible.mitochondria have been described as "the powerhouse of the cell because they generate most of the cell's supply of adenosine tri phosphatase ATP used as a source of chemical energy.

 History
              the frist observations of intracellular structure that probably represented mitochondria were published in 1840 Richard altmann.in 1894 established than as cell organelles and called then 'bioblasts'  the tram 'mitochondria' was coined by carl benda  in 1898.
                   Friedrisch meves, mode the first recorded observation of mitochondria in plant in cell of  the white waterlily Nymphaea alba.
                                       

Origin 

            A mitochondria contains DNA,which is organized as several copies of a single,circular chromosome. this mitochondrial chromosome contain genes for  redox protein ,such  as those of the respiratory chain. the CoRR hypothesis propses that location is required for redox regulation. the mitochondria  genome codes for same RANs of messenger RANs into protein.the circular structure  is also  found in prokaryotes.  

Structure

                 mitochondria contains outer and inner membranes composed phospholipid and protein. the two membranes have different properties. because of this double-membrane organization,there are five distinct part to a mitochondria.

1-the outer mitochondria remembrance

2-the intermembrance . space( the space between the 

outer and inner membrancs)
3-the inner mitochondrial membrane
4-the cristae space(formed by infloding of the inner membrane)
5-the matrix(space within the inner membrane)
                                                       

Outer membrance.
                                the outer mitochondrial membrane, which encloses the entire organelle,is 60 to 75 angstroms thick.it has a protein to phospholipid ratio similar to that of the eukaryotic plasma membrane.
Inter membrane space 
                                      the intermembranec space is between the outer membranes and inner membranes .it is also know as perimitochondrial space.
Inner membrance 
                              the inner mitochondrial membranes contains proteins with five type of fountions.
1-thise that perform the redox reactions of oxidative phosphorylation.
2-ATP syntheses which generate ATP in the matrix.
3-specific transfer proteins that regulation mettabolite passage into and out of the matrix.
4-protein import machinery.
5-mitochondrial fusion and fission protein. its contain more than 151 different polypeptides and has very hight protein to phospholipid ratio(more than 3:1 by weigh,which is about protein far 15 phospholipid.

Cristae   
              the inner mitochondrial membrane is compartmentalized into memerous cristae,which expand the surface area of the inner mitochondrial membranes.enhancing its ability of produce ATP

Matrix 
             the matrix is the space enclosed by the inner membrane.it contains about 2/3 of the total protein in a mitochondria.the matrix is important in the production of ATP with the aid of the ATP.
synthase contained in yhe inner membrane.the matx concentraed mixture of hunddreds of enzymes. special miotchondrial ribosome. tRNA and sevral copies of the mitochondrial DNA genome of the enzyme, the majar fuctions include oxidation of pyruvate and  fatty acid and citric acid cycle.

Make energy
                      Mitochondrial are aften  referred to as power house of the cells. the generate the energy that our cells need  to do their job. for ex-brain cells  need a lot of  energy to be able to communicate with  each  other and also  to communicate  with parts of the  body  that many  be for away.
mitochondria generate chemical energy, similar to the type of energy you get from the battery .the energy made by the mitochondria is in the form of a chemical called adenosine tri phosphoate or ATP for short from. ATP is the energy currency  that every cell in  our body can use and  it keepsus  alive. the  machinery that mitochondria use to mkr ATP is called the electron transport   chain.




GOLGI BODY/ GOLGI COMPLEX/GOLGI APPARATUS
                                                                                                   In 1890, Camillo Golgi first discovered this complex in the cytoplasm by silver nitrate staining  method.
In 1941,Raman cajal,named Golgi apparatus and studies its function.
In 1910,Perroncito  studies in  plant  and called  dicytosomes
Golgi complax occurs in  all living  cells except RBCs, prokaryotic cells,and mature  sperm mature sieve tubes bryophytes, pteridophytes  ,etc
                                            Both morphologically and functionally it is related  to  the endoplasmic  reticulum. Golgi complex  consist of group of membrane bound spaces  which are the following type;-
1-CISTERNAE 

                          Cisternae form the  central  plate like group of tubular  or flattened compartment  of about 20 Angstrom wide and enclosed  by unit membrane.these are  parallel bundles  one above the the other are separated  by  intercisternal  spaec of  about  200-300 angstrom there membrane varies form 3-12.these are  slightly curved.the convex surface  is  called  firming face or cis face  and toward  nuclear  envelop or  ER while  concave surface  is called  maturing  face  or trans face  and toward  the  plasma  membrane.

2-Tubules

                Cisternae forms sa peripheral complex  network called  tubules.

3-Vesicles 

                 These  are small  drop  like structure  about  400-800 Angstrom in diameter. these are associated with convex forming face  of golgi complex and  that is  next  to smooth ER.these devlop from  the cisternae of  ER and  fuse to from golgi cisternae.

4-secretory vesicles

                                 these are present  on the side  of from the trans face of golgi cisternae.these  are pinched off product  of golgi  and are  finally  converted  into  zymogen  granules or lyosomes.

5-Coated vesicles

                                           in the some cell types.the secretory  vesicles  are coated  with  a layer of protein. these  are called coated vesicles.these  are associated  with the secertion  of  highly specialization  cell  products.

       

Functions 

                 1-Secretion-

                                      Golgi complex is mainly associated with the secretory  activity of the cell.thought the  channels of  golgi there is a  continuous traffic  of  are substances from  cell to  the outside.these substances are synthesized  elsewhere  in the  cell and concentrated  and modified  by the  golgi  complex. finally  these  are  secreted  outside.these  include enzymes,hormones, endocrine secretion etc.

2-Conecntration and  storage   of secretory products

                                                                                       Golgi complex is associated with conecntration storage, condensation  and parking  of material. the glycoproteins  and lipoprotein  are  concentrated  and  packed  in secretory vesicles which bud of  from golgi cisternae.

3-Formation  of lysosomes

                                             primary lysosomes  are formed from golgi cisternae in  the same way as the secretory  vesicles.

4-Synthesis of glycoproteins

                                               Golgi complex  facilities  the  linking  of  carbohydrate  and  protein  in the  formation  of glycoprotein.

5-synthesis of carbohydrate

                                              Golgi  apparatus  is  considered  to  the main  agency of  building  of  large molecules  of carbohydrate  from simple sugars.

6-Formation of cell plate

                                           Golgi complex produces vesicles  during  anaphase  of  mitosis.these vesicles  fuse  to  from the  cell plate.

7-Formation of  cell wall

                                          Substances  necessary  for  the  formation of  cell wall are synthesized and  secreted  by golgi  complex

8-formation of acrosome  

                                           Acrosome of  sperm develops from golgi complex.

NITROGEN CYCLE

                                   Nitrogen is found in the atmosphere  in the highest concentration  about 79% in the from  of  nitrogen. It is essential  component  of protein  and chlorophyll  found in organisms. Nitrogen   not directly taken by animal and plants  from the atmosphere. nitrogen gas is converted into  combined  from  by  a biological  mean ( for ex- though lighting  and  rain fall  or artificially  in the  fertilizer industries  at a very  high temperature and pressure) and by same prokaryotic  microorganisms (for ex- bacteria and cyno bacteria).The nitrogen is made available to plant as protein  though  free-living  and symbiotic  microbes the animal ingest  plant  protein.Thus nitrogen becomes a building  block of a.a (amino acid)protein  and cell well of all organisms.Upon death  their organisms  undergo  decomposition  and make  building  block in free elemental forms.The nitrogen fixing  micro organisms are called  diazotophs and  the phenomenon  of this  activity  is  know as diazotophy. 

The important stages of Nitrogen cycle are-

1-Ammonification 

2-Nitrification

3-Denitrification

                                                                           

1-Ammonification:-

                                  During the course  of organic complex from  of organic  nitrogen is  blocked by micro organisms into  the  more stable inorganic  form.This process is called nitrogen Ammonification.  As  a result, ammonia is  formed  and organic  nitrogen disappears.

The process is as follows-

       Complex organic matter + H2O________2NH3 +CO2

       NH2_C=O_NH2 +H2O__________ 2NH3 +CO2

Microbiology:-

                         A variety of   microorganisms  producers  ammonia  from  organic  ntirogen compounds. These include 

1-Bacteria-Ex Pseudomonas ,Bacillus,Clostridium, Micrococcus, etc

2-Fungi Ex- Alternaria, Aspergillus,Mucor, Penicillium, Rizopus, etc  

2-NITRIFICATION:-

                                     The process of oxidation  of ammonium ions  to nitrite ions  and  subsequently  to nitrite ions  is know as nitrification.Ammonium ion, the most reduced  firm of  inorganic nitrogen acts as the  starting point  for nitrification. Nitrification   was  discovered  to be a  biological  process  by schloesing  and   Muntz in 1877. Winogradsky isolated  the  bacteria  responsible   for  biological   nitrification in 1890.

                        

        

                   2NH3 + 3O2 ___________________ 2NO2 + 2H ions+ 2H2O

 in presence of nitrification  bacteria  and release of two hydrogen ions

                               2NO2 ions + O2 _______________ 2NO3 

nitrifying  bacteria presence on this reaction.

Microbiology:-

                         This process is usually  associated  with  energy  yielding reaction  in metabolism of  autrophic bacteria.Such  bacteria  that carry  by two separate groups of bacteria.-

 1- ammonia oxidizing bacteria or nitrosifying bacteria 

2- nitrite oxidizing bacteria  or nitrifying bacteria.

  

1-Ammonia Oxidizing bacteria- 

                                                    The bacteria are -Nitrosomonas , Nitrosococus,Nitrosolobus,Nitrosospirea, Nitrosovibria

2-Nitrite  Oxidizing Bacteria:-

                                                  The  bacteria   are  Nitro bacter  Nitrospira, Nitrococus.etc

Mostly  nitrification  is  carried by autotrophic bacteria  but  there  are some  hetrotrophic  bacteria  and  fungi  which also taken  part in the nitrification.

Ex- Nitrosomonas, aspergillus flavus.

3-DENITRIFICATION:-

                                           When nitrate and  is  added  to soil, NO2 ions, N2O(nitrous oxide) and N2 are formed  after  reduction  of nitrite. Microbial  reduction of nitrate  with  the liberation  of  molecular  nitrogen  and  nitrous oxide  is called  denitrification.

                             

 2HNO3 ___________2HNO2______ 2NO2_______ N2O______ N2

 presence of hydrogen and water ions.

Microbiology

                       Dinitrification ic carried out  only  by  Pseudomonas, Bacillus,  Paracocus, Thiobacillus, Denitrification  Chromobacterium, corybne bacterium, hyphomicrobium, etc

GIANT /LARGE CHROMOSOME

                                                     Polytene  Chromosome;-  polytene  chromosome  was  first time  seen by  an Italian cytologist  Balbiani  in 1881.But there not recognized  as chromosome. In 1933 Painter,Bover and Heitz described  their structure. The polytene chromosome occurs  in the nuclei of salivary glands,epithelial living of guts of Drosophila  and  some  fat bodies of the larval  stages of certain  insects  such as chromosome(class- Diptera),these are described as  polytene  chromosomes. In Drosophila malenogester (fruit fly) the size of polytene  chromosome is about  1000 time large  than the  of the somatic chromosomes. The  ploytene  chromosomes are  regarded  as multi stranded  structure  being composed of  a  number of fibers  or chromosomes.The  polytene chromosome also represent  a distinct pattern of transverse binding. Its consist of  colored bands alternating  with light  colored areas the inter bands.The dark bends  are  feulgen positive i.e they  are formed of  hetrochromatin. The inter bend are  feulgen negative and are  formed  of  coiled  30 nm chromatin fiber. The bend are genetically  active  sites. The are nearly  5000 bends in polytene  chromosomes of  Drosophila larva. Polytene chromosomes in the  addition to  bends and  inter bends  also have  special  enlargement  and extension  of  bends  into  lateral  loops or puffs. These large puffs  are called  Balbiani rings,These comes out into a series of  loops these loops increase  thickness or diameter of the chromosome.

                                                               

                                                           

LAMP BRUSH CHROMOSOME;-

                                                            The Lamp Brush Chromosomes  are  giant  size  chromosome  are   found in oocytic  nuclei  of those vertebrates  which  have large yolk  containing  egg.These  can be seen  by naked  eyes. Lamp Brush Chromosome  resembling  like  brush  used for  cleaning  lamps. Lamp Brush chromosome were first time  seen by  Flemming in 1882. and In 1892, Ruckert named  them Lamp Brush because of their shape. Lamp brush chromosome are found  in oocytes  of insects, Amphibians ,reptile,birds and sharks. These  have also  been  found in the plants and invertebrates. These may be  as long  as 1000 micro meter or  more and about  20 micro meter  in width.In salamander (amphibian)  oocyte  these  may attain  a length  of  about  5900 micro meter. A lamp brush chromosome in diplotene  stags consist of  two  homologous  chromosomes  which are in contact only at  certain points know as chiasmate. Each chromosome of the pair id formed  of two sister chromatids  which  present  parallel and  form the  chromosomal axis  or  the main axis. The axis is about  4000 micrometer  long  while  in  ordinary  chromosome its  is 10 micrometer.

It is differentiated  into the following-

1- Highly condensed darkly  stained  chromosomes alternating with  light colored  inter bends.

2-Large de condensed  chromatin loop or lateral loops.

3-Less de condensed chromatin that  joins  that  adjacent chromomeres.

4-The chromosome axis, the chromosomes and the loops axis  all are formed of DNA.

1- THE CHROMOMERES;- 

                                                 These are are found in pairs,one chromomeres on each  chromatial. These  are about 0.25 to 2.0 micrometer in diameter and  are spaced about 2micrometer   from   center  to   center along chromatid axis  these represent  hetero chromatic  regions which axial  filament remains  tightly  coded.these are  transcriptionally inactive.

2-LATERAL LOOPS;-

                                       These arise  from  the  chromosomes and are about  10,000in the  number in each chromosome in amphibian oocyte .Each  loops  extends on the side of  the  chromatid  axis  about  5-50 micrometer long  and about 30-50 Angstrom  in the diameter. Since there are two  chromosome and two chromatids, there are four copies  of  each  lateral  loops  at each given  position. each  loops  consist of an  axial fiber  formed  of DNA. It is  surrounding  with  matrix composed  of m-RNA and proteins.

this topic for M.sc(zoology) helpful 

  

         CORAL REEFS

                                     Corals  are animal belonge to the phylum coelentreta.these have foumd in the sea water.these salitary or colonical ploypoids from and live in the skelaton to calcium carbonate secreted by themselves.some of them grow into huge mounds while other are largeand  branched colonies.however,most of the corals belong to the class to yje amthozoa and few other to the class hydrozoa. the hydrozoa corals are colonical from and secrete massive exoskeleton belong to  the milleporia, egmillepora. these are corals founds with the other corals formin g huge mounds.

                   Sevral stony corals produce reefs of calcareous rocks and ulytimatly dry land. reef corals in living condition from one of the most complex and fascinating marine comnmunities and  as such as are of great interest from  ecological and  biological stand points.

                                           Reef building corals are strictly tropical and require warm, shallow water. therefore coral reefs are limiteds only to  continential and island shore in  tropical and sub tropical zones. these corals can bear tempreature below  18 degree cellcius. above 22 they flourish. Corals reefs thrive well in water deeper than live as deep as 80 meters and more.Coral reefs inhabit water including Florida, Bermuda The Baharmas and the west Indies and Indo pacific region. 

        

        COMPONENTS OF  CORAL REEFS

                                                                         In addition to stony corals,other components  in the formation of the corals reef are millipora, tubiora, heliopora,alcynaria,gorgonians, forminifera, coralline alge and branching  alge etc

       DEFINITION 

                                Vaughan 1917 has defined a coral reef "A coral reef is ridge or mound of limestone, the upper surface which is near the sea and which is formed of calcium carbonate  by the action of  organism chiefty corals."

       TYPE OF CORAL REEFS

                                                     Hyman 1940 describe  that there are three type of coral reefs

         1-Fringing reef

         2-Barrier reef

         3-Atoll

    

      FRINGING REEF

                                   It is a ridge of corals also referred to as shore reefs  formed from  the sea bottom they occurs very near the shore, a few feet to 0.4 km away having sometimes channels and pools, due to the reptured  in the  reef. Channel and  pools are inhabited bydiffrent type of colured  animals and coral. they are also found in mud, dead coral and  other masses of rocky fregments.

  

      BARRIER REEFS

                                      It is a just like a fringing reef but the main difference is that in this a wide  channel  is  presnt in which  large  ships  can sail.The example in great barrier reef of Australia. It is  a largest barrier reef and in 2160km in lenght and  is about 40 to 144 km,away from the shore. Navigble  channel  called lagoon  seperated  these  reefs from  the shore. The lagoon may be  20 to 40 fathoms deep becomes  navigable. Sometime, a barrier  reef  surrounded as  island  captain cook sailed  in the coral  reef of Australia and  for  960 km. after which his ship was wrecked.

  

      ATOLL

                   It is the coral island and consists of  a belt of coral reef having  central shallow  lake  communicating with the sea. It is horse-shoe shaped  or circular reef  enclosed the lagoon. These  lagoon  64 to 80 km across. sevearl  of such atoll  occur in  south pacific. The atoll  of biknii  is very famous and  has a land  of 459.2 squar km. And  a shollow  lake of 448 km. another atoll , which is very  famous  due to  prominence in world  war second is atoll of tarawa.

                                                                  

         REEF FORMATION

                                              Several theories  have  been put forword  about the problum of  reef  formation. As the coral,which are builder do not grow 45 meter at the outside  and its also  known that coral  in the  past ages  belonged  to sea-shore, the  difficulty arose how  those  coral reefs attained vertical  growth.theories propounded for  the explaination of the reef formation are as follows

1-Darwin-Dana subsidence theory

2-Semper-murray solution theory 

3-Daly glacial-contral theory

      1-DARWIN-DANA SUBSIDENCE THEORY 

                                                                                  Charles Darwin's theory explains the  formation  of reef. According to him the reefs began as  fring  around  slowly sinking shore. which  continue  to grow  upwords and  the land  sinks. thus  the fringing  reefs turn into a barrier  reef when  coast  subsides. the lagoon  sepreating it from the  reef become  wider  and wider  island surrounded by  barrier reefs finally sink beneath the   lagoon. thus,the  encircling reef is left on which islands   of wave  tossed. atoll are  formed as  accumulation  of loose fragment of rocks.

    2-DALY GLACIAL-CONTRAL THEORY

                                                                          Submerged bank theory and daly glacial-contral theory are wiedly favoured by zoologiests about  reef  formation.Darwin's theory od subsidence has also gained  great  support,In 1904 a socity  od london, which  started the work  of boring  on funa futi Atoll in the  south pacific , north  of fiji and  the result supported the subsidence theory. Cary 1931 made  three borning from  the shore  into a reefs in sanoa and  the result confirmed Daly Glacial-contral theory\.Two  boring were  done  in great  barrier  rref committee, each in 1928 and  in 1938. there is evidence that coral reef are growing today on sumerged land  and the foundation of reef are now at much greater depth than they were whn coral first began to grow.

   

   its topic helpful in m.sc in zoology