Notes Ghar

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 Coelom is one of the characteristic features of metazoans. The true coelom is a body cavity formed during embryo development from the three germinal layers. The body cavity meaning a fluid filled space that can accomodate organs. The coelom is lined by mesodermal epithelium cells. Presence or absence of coelom is one of the criteria for classifying animals.                                      Fig :- coelom Animal Kingdom:-  1. Acoelomate(no coelom)     Ex:-Porifera ; Coelenterata ; Ctenophora; Platyhelminthes 2. Pseudocoelomate(false coelom)          Ex :- Aschelminthes 3. Coelomate(true coelom)            Ex :- Annelida ; Arthropoda ; Mollusca ; Echinodermata ;Hemichordata ;Chordata Coelom Definition  “The coelom is the fluid-filled body cavity present between the alimentary canal and the body wall.” The true coelom has a mesodermal origin. It is lined by mesoderm. The peritoneal cavity present in the abdomen and similar spaces around other organs such as lungs, heart are parts of t

  Prototheria (Gr., protos-first + theria- beast) Primitive, reptile like , oviparous (Eg. Echina ‘spiny anteater’) General feartures  :- Marsupials brood pouch on the ventral side occupy a wide variety of niches and varied in diets Viviparous  warm blooded Body covered by hair Pinna well developed Mammary  glands have tits All digits are clawed Skull dicondylic Mandible is a single bone called is Dentary Orbital  and temporal fossa and are congruent  Seven cervical vertebrae is Y shaped bones in caudal vertebrae  4 th toe is largest in hind limb, serves as axis of foot Clavicle is well developed. Inter- clavicle is absent Penis is present in  some animal it is bifurcated Fertilisation and initial development is internal Young ones are born in an immature state Affinity with prototheria :-                                                                 Cloaca presents                                                Play vehicle present.                        Corpus callosum absent.    

 Canal system in sponges  There are three different types of canal system found in sponges are as follows :- 1.Ascon type:- eg. Leucosolenia Simplest type of canal system Spongocoel is lined by flagellated caller says or chanocytes Ostia open into is Spongocoel  which is a single , large , spacious cavity in the sponge body Spongocoel open to outside through a narrow circular opening called the osculum  located at the distal free end Flow of water is slow because the large is Spongocoel  contains much water that cannot be pushed out readily  through a single osculum Ingressing water - Ostia - spongocoel - Osculum - water outside 2.Sycon type :- eg - scypha, Grantia In more complex Sycon type  incurrent canals are irregular branching and anastomosing,forming large sub dermal spaces. There are two types of canals are found in as sycon type in current and radial Alernate with each other Incurrent pores (dermal Ostia) found on outer surface of the surface of the body open into prosopyles .

Placenta Placenta :-  Placenta is a temporary intimate  mechanical and physiological connection between foetal and maternal tissues for the nutrition, respiration and excretion etc.   The placenta is the passage that unites the fetus to the mother. The placenta facilitates the exchange of nutrients and oxygen to the fetus. It is also responsible for collecting carbon dioxide and waste materials from the fetus. In appearance, the placenta is disk-shaped and measures up to 22 cm in length. The placenta is also rich in blood vessels. The placenta is exclusive to mammals. The umbilical cord connects the foetus to the placenta, facilitating the transfer of materials. The placenta is usually attached at the top, bottom, side, front or back of the uterus. In extreme cases, the placenta gets attached to the lower part of the uterus resulting in a condition known as placenta previa. In human meta-distal placenta is present The placenta  is fully formed in 10 weeks and last throughout the pregna

 Origin of Bilateria                                        First meta zones are very likely to radial animals Believed that bilateral symmetry evolved in radical ancestor when it is started creeping There are several theories given by many scientists for the Bilateria symmetrical animals are as follows:- 1.Ctenophore polyclad Theroy  :-  Ctenophores provided a a bridge or intermediate forms between                 radiate coelonterate and ancestors  and bilateral polyclad flat warms. Based on resemblance:- Oval flat and shaped with dorsal ventral differentiation Creeping on entire ventral surface Presence of two dorsal tentacles Centrally located ventral mouth Radiating, anastomosing nervous system Swimming larval stages of polycalds have eight ciliated lobes and comparable  to 8 comb rows of ctenophore  Limitations:- Cleavage is biradical in ctenophore but spiral in polyclad  Acoel flatworms are now regarded to be a most primitive 2.Planuloid-Acoeloid Theroy:-   Ludwig Von Graft form

 Phylum : Onychophora External morphology :- Body is elongated cylindrical and electrical symmetrical External segmentation is unique clear and and jointed legs number from 14 to 43 pairs Each leg is stumpy pro tube bill ending in two clause 3 to 6 pets on the ventral side which serve as a walking souls which constant to the substratum Skin is covered in a tin cuticle covered in numerous Billberry possesses The skin is thrown in transverse ridges bearing a chronicle because in the city news the spines Anterior end is not differentiated as a head .bears  a pair of of eye , a pair of pre-oral Antennae and simple separating or a bailable and meet the ventral mouth with pair of Chetan years George Antony or not not homolog us to 3 segmented head is midway between Annelida and Arthropoda. Anus at the posterior end and genital aperture located is front of anus..

Major and Minor Phyla Concept of major or minor phyla depends on:- Number of species and individuals. Participation in ecological communities. 9 are regarded as major phyla : Protozoa, Porifera, Colenterata, Platyhelminthes, Nematodes, Molluscs, Annelida , Arthropoda, Echinodermata  Minor phyla  :  Rotifera , Acanthocephala, Nemertinea , Pogonophora

                  Branches of zoology   Zoology is the division of biology that deals with the animal kingdom. It is the scientific study related to the entire species of the  animal kingdom An ancient Greek philosopher, Aristotle, was a first-person to broadly classify the living things in the 4th century BC. Firstly he divided living things into animals and plants and then continued with his further classifications. Later the words like biology, botany, and zoology came into existence. The study of zoology includes animals physiology,  their behaviour, and their interaction with other species in their environment. It is a huge course that includes the distribution of every animal species on earth including extinct animals. Apart from the animal kingdom and ecosystems , zoology also explores the new areas of research. Later, Aristotle divided animals into two classes: one with red-blood and another without such as insects and crustaceans. Then, he further classified creatures into tho

ZOOLOGY  ( Zoo-Animal;Logos-Study of  ) It is the branch of biology that studies the animal kingdom.                   It includes the structure , embryology , evolution , classification , habitats ,  zoo-geography , embryology and animal behavior etc.. FATHER OF ZOOLOGY  :- ARISTOLE FATHER OF INDIAN ZOOLOGY :-ARISTOLE RANGE OF ZOOLOGY OF FAUNA KINGDOM :-  9LAC. - 12LAC. (acc.to zsi (2004)).                 History of zoology in india :- In India , zoological study start since ancient times when the animals are rearing and domesticated it was proved from bhimbetka painting (in M.P ) during Paleolithic and Mesolithic period of time..