Poultry Farming - Economic Importance | Biology Class 12

Zoology | Notes
Poultry Farming
Class: 12

Poultry includes several types of birds like chicken, ducks etc. and rearing of poultry for the commercial production of meat and egg is called poultry farming. In Nepal poultry industry primarily includes culture of chickens for meet, eggs and fertilizer. In the poultry industry fast growing verities are used and are raised in the well ventilated sheds. There should be proper arrangement of food and continuous supply of fresh water is necessary. Following types of sheds are necessary for poultry farming.

Test Tube Baby (Invitro Fertilization Technology) | Biology Class 12

Zoology | Notes
Test Tube Baby (Invitro Fertilization Technology)

Class : 12

Normally conception occurs when an ovum from an ovary fertilizes with sperm in fallopian tube. The fertilized egg called as zygote travels towards uterus where it is implanted and grows. But many couples cannot conceive pregnancy because of low sperm count, blockage in fallopian tube abnormal sperm and others alike. Test tube baby technique is a method that enables the couples having fertility problems to bear child. In this technique, the ova and sperm are fused in test tube where all the essential nutrients are available. As fertilization is artificially done in test tube, the test tube baby technique is also called as in vitro fertilization (IVF technology) 

Amniocentesis (Amniotic Fluid Test) - Procedure | Biology Class 12

Zoology | Notes
Amniocentesis (Amniotic Fluid Test)

Class: 12

Amniocentesis also called as Amniotic Fluid Test (AFT) is a medical procedure in which amniotic fluid is taken out from the uterus of pregnant woman to determine genetic arrangement and sex of the fetus. Amniotic fluid contains fetal cells and wastes from the fetus and a fluid is used for prenatal diagrams of dmomosomal abnormalities, genetic disorder, sickle cell, anemia and Cystic fibrosis. Amniocentesis is performed between 14-16 weeks of pregnancy. The term amniocentesis refers to the process in which the fluid is tested between weeks 11 to 13. These are four purposes of amniocentesis:

Ionic Equilibrium - Postulates of Arrhenius Theory of Ionization | Chemistry Class 12

Chemistry | Notes
Ionic Equilibrium - Postulates of Arrhenius Theory of Ionization

Class : 12

In 1887, Svante Arrhenius, put forward a theory to explain the properties of electrolytes in solution. This theory is known as Arrhenius theory of ionization or electrolytic dissociation after his name. The main points of the modern form of the theory are given below.

Tissue or Organ Transplantation and Its Types | Biology Class 12

Zoology | Notes
Tissue or Organ Transplantation
Class : 12

Tissue transplantation is the process of replacing non-functional, damaged or lost body part with functional ones. It is carried out only when the survival of the patient is at danger. The most successful transplantation is one where tissue is taken from one place of person’s body and moved to another place in the same such as skin grafting from the thigh to replace burn tissue of hand. The tissue or organ which gets transplanted is called graft. There are many examples of tissue or organ transplantation on human beings such as skin grafting, heart transplantation, kidney transplantation etc. 

Vaccine Preparation - Types and Uses | Biology Class 12

Zoology | Notes
Vaccine Preparation 

Class: 12

Any substance that causes activation of an animal’s immune system without causing disease is called vaccine. Vaccine contains antigens that stimulates immune system for producing antibodies reacting to the antigen and increases immunity. The vaccine can be given orally or injected into the body and develops active immunity. Vaccine has harmless derivative of antigens and increase the defenses against the pathogens. The immune system of an animal produces photogenes chemicals against the antigens and is called as antibodies.

Energetic of Chemical Relations and Chemical Thermodynamics | Chemistry Class 12

Chemistry | Notes
Energetic of Chemical Relations and Chemical Thermodynamics
Class : 12

Some Thermodynamic Terms 

In order to study the laws of thermodynamics, it is essential to understand certain terms quite oftenly used in thermodynamics. These terms have definite meaning. Some of the most commonly used terms are given below.

Immunity System and Its Types | Biology Class 12

Zoology | Notes
Immunity System
Class: 12

The organisms are surrounded by and environment that has numerous bacteria and other disease causing agents called aspathogens. The pathogens after entering the host secret chemicals called as antigens. The antigens stimulate the host body to secret pretentious chemical as antibodies. The antibodies react with antigens and make the host free from disease. This ability of the body is called immunity and the system involved during the process is called immune system. The immune system has ability to recognize, remember and destroy different antigens.

Epithelium Tissue and Its Types | Zoology - Biology Class 12

Biology - Zoology | Animal Tissue
Epithelium Tissue

Class : 12

The word epithelium is composed of two words epi and thelis which mean on and grows respectively. Thus epithelium is a kind of tissue which grows upon another kind of tissue. Therefore it is also called covering tissue. The cells of epithelium are compactly arranged and form thin cover of single layer or multi layer. The epithelium tissue remains connected to another tissue by means of basement membrane which is permeable for exchanging useful and harmful substances.

Conductors and Non-Conductors - Classification | Chemistry Class 12

Chemistry | Electrochemistry
Conductors and Non-conductors
Class : 12

The substances which allow the passage of electric current through them are called conductors. It may, however, be pointed out that all conductors do not conduct electricity to the same extent. Depending upon the ease with which they allow the passage of electricity, they are termed as good conductors or poor conductors. Although it is not possible to sharply distinguish between the good and poor conductors, but a rough division is possible on the basis of relative ease with which the conductor allows the passage of electricity. The substances which do not conduct electricity are called non-conductors or insulators.