Category: Biology Second Paper

1. It builds immunity against germs.
2. It stops the growth of microorganisms.
3. It inactivates the antigen.
4. It destroys the effectiveness of the toxin.
5. It cures diseases in animal body.
6. Their molecular weight is 1,50,000-9,00,000.

Antibodies are proteinaceous substances that neutralize antigens. Antibodies are chemically known as globulins or immunoglobulins. The human body can produce about 100 million (10 crore) antibodies. 85% of immunoglobulins are polypeptides and 15% are carbohydrates. Antibodies are produced from spleen, lymph glands, bone marrow, tonsils, thymus, appendix etc.

There are three types of antigens in human blood. Namely- A, B and Rh.

Antigens can be mainly divided into two categories based on location. namely-

1. Exogenous antigens: Antigens produced outside the body are called exogenous antigens.
2. Endogenous antigens: Antigens that are produced inside the organism are called endogenous antigens. For example, Forsmann antigen, cardiolipin antigen etc

1. Antigens are toxic proteinaceous substances. However, polysaccharides and lipoproteins can also be antigens.
2. Its molecular weight is 10,000 daltons. But the best antigen has a molecular weight of 100,000 daltons.
3. It can bind to antibodies.
4. It may contain multiple epitopes or determinant groups.
5. Different organisms of the same species have species-specific antigens.
6. Organ specificity antigens are present in certain tissues or organs.

Antigens are toxic protein-like substances that bacteria release to weaken the host body

The immunity acquired by the transfer of antibodies from one body to another is called passive immunity. Passive defense is of two types. These are-

(i). Natural Passive Defence: Antibodies come from the mother’s body to the baby through colostrum and colostrum. It makes children immune to disease.

(ii). Artificial passive immunity: The body is made immune to disease by transferring antibodies from one body to another through injection.

The defense achieved through the production of antibodies in the body is called active immunity. Active defense is of two types. These are-

(i) Natural Active Defense: Infection occurs when humans are involuntarily exposed to microbes. All these germs are eradicated by naturally acquired abilities.

(ii) Artificial active immunity: Humans acquire this immunity through inoculation or vaccine. For example, DDP vaccine is taken for diphtheria, tetanus vaccine for scurvy and pertussis vaccine for whooping cough.

The ability to respond to microbes after birth is called acquired immunity. Acquired immunity is a specific immunity. It is of two types.

Active defense and passive defense

1. Active Immunity: The defense achieved through the production of antibodies in the body is called active immunity. Active defense is of two types. These are-

(i) Natural Active Defense: Infection occurs when humans are involuntarily exposed to microbes. All these germs are eradicated by naturally acquired abilities.

(ii) Artificial active immunity: Humans acquire this immunity through inoculation or vaccine. For example, DDP vaccine is taken for diphtheria, tetanus vaccine for scurvy and pertussis vaccine for whooping cough.

2. Passive Immunity: The immunity acquired by the transfer of antibodies from one body to another is called passive immunity. Passive defense is of two types. These are-

(i). Natural Passive Defence: Antibodies come from the mother’s body to the baby through colostrum and colostrum. It makes children immune to disease.

(ii). Artificial passive immunity: The body is made immune to disease by transferring antibodies from one body to another through injection.

1. Barriers: Human skin, alimentary tract, respiratory system, genital tract act as barriers.
2. Innate killer cells: Innate killer cells are a type of white blood cell or lymphocyte. It destroys virus infected cells and tumor cells.
3. Interferon: Interferon is a high molecular weight glycoprotein. It is produced by virus-infected cells and prevents the virus from multiplying.
4. Complement system: Complement system is a group of 20 types of plasma proteins. These inactive proteins are converted into active proteins that kill the bacteria.
5. Inflammatory response: Macrophages and neutrophils are activated and destroy the microbes.
6. Symbiotic bacteria: Symbiotic bacteria live in the body’s skin, genitals and digestive system. They destroy microbes by secreting chemicals.

Defenses that are acquired from the maternal body through immortality, are present in the body for life and are rapidly effective are called innate defenses. This is called genetic immunity.

Different types of innate defenses are-

1. Personal defense: When a person resists germs through his own immune system, it is called personal defense.
2. Species defence: Attacks by microbes are limited to specific species and only those specific species resist the pathogen. For example, the malaria parasite is limited to humans and mosquitoes.
3. Group immunity: If one group of people is infected by a parasite, the other group can easily resist it. For example, whites are more affected by tuberculosis than whites.