Notes Ghar

  Regression analysis Regression like , relation is a study of a relationship between variables  Simple regulation : single explanatory variable  Multiple regression : includes any  number of explanatory variables Dependent  variables : The single variable being explained/ predicted by the regression model Independent variable : Explanatory  variables used to predict the dependent variable Residuals :Portions of dependent variables  is not explained by the model Correlation  tests or closeness and direction of relationship between the two phenomena . Regression  gives the nature and extent of this  relation, so that prediction  can be made about dependent variable, for any value of independent variable. Clearly designates one  variable as cause and the other effect , unlike the correlation Linear regression :straight line relationship, Y=mx+c  In least square method of regulation ‘m’ and ‘b’ are calculated by equating the differencal of Loss Function (Yi-Pi) to zero Formula:- =  de

Resisting worms 30/05/2021   Do worms have an immune system? How do they fight infections? Roundworms (Caenorhabditis elegans) are animals that lack dedicated immune cells. But they are constantly under attack from viruses and fungal parasites called microsporidia. Researchers from the U.S have now decoded the complex dynamics that are involved in how these organisms sense an infection. The paper published last month (Plos Pathogens) notes worms can sense changes in their metabolism and then unleash protective defenses, even if they don't directly sense the pathogens. The team studied an important biological pathway in the worms – the purine metabolism pathway. The results suggest that the host has developed ways to sense the theft of purine metabolites. It seems that when these key cellular building blocks are stolen by the pathogen, the host senses this theft to mount an immune response to the pathogen, explains first author Eillen Tecle in a release. The team adds that studying

  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 .

  Forensic Entomology  Forensic  entomology is the Scientific study of the invasion  of the succession pattern of arthropods with their developmental stages of different species different in species  found on the decomposed cadavers during the legal investigation.                     It is the application and study of insects , arachnids , centipedes ,  millipedes and crustacean to criminal or legal cases.It also helps to detect drugs and poisons, determine the location of an incident and find the presence and time of the infliction of wounds.                 Forensic entomology has 3 sub fields :- Urban forensic entomology:-    urban forensic entomology typically concerns pests infestation in building , gardens or that maybe basis of litigation between private parties and service providers such as landlord or extreminators. It helps to determine chain of custody , when all the possible infestation are examined in order to determine who is at fault. Stored - product forensic entomology

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