All questions of Human Health & Diseases for NEET Exam

The Widal test is one method that may be used to help make a presumptive diagnosis of enteric fever, also known as typhoid fever.The test was based on demonstrating the presence of agglutinin (antibody) in the serum of an infected patient, against the H (flagellar) and O (somatic) antigens ofSalmonella typhi.

Its given in 12th NCERT.... widal test for typhoid

When a mosquito feeds on an infected person, the mosquito can become infected and can bite and infect others. The Aedes aegypti and Aedes albopictus mosquitoes transmit chikungunya. They also transmit dengue fever, another disease caused by a virus.

Most microbes belong to four major groups: bacteria, viruses, protozoa or fungi. (To find out more, see the “Bacteria/Viruses/Protozoa” fact sheets). Disease-causing microbes can also be called pathogens, germs or bugs and are responsible for causing infectious diseases.

Antibodies are produced by specialized white blood cells called B lymphocytes (or B cells). When an antigen binds to the B-cell surface, it stimulates the B cell to divide and mature into a group of identical cells called a clone.

Human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV).Following initial infection, a person may not notice any symptoms or may experience a brief period of influenza-like illness. Typically, this is followed by a prolonged period with no symptoms. As the infection progresses, it interferes more with the immune system, increasing the risk of developing common infections such as tuberculosis, as well as other opportunistic infections, and tumors that rarely affect people who have working immune systems.[5] These late symptoms of infection are referred to as acquired immunodeficiency syndrome (AIDS).This stage is often also associated with unintended weight loss.

Sporozoite is the infective stage of the malarial parasite. They are present in the saliva of infected female anopheles mosquito.

Anti venom against snake poison contains antibodies.

Explanation:
Anti venom is a serum that is used to treat snake bites. It contains antibodies that are specifically produced to neutralize the venom of a particular snake species. The antibodies are produced by injecting a small amount of the snake venom into an animal, usually a horse, and then collecting the blood serum from the animal after a certain period of time. This serum contains the antibodies that have been produced in response to the venom.

The antibodies in the anti venom work by binding to the venom molecules and neutralizing their toxic effects. This prevents the venom from causing damage to the body and allows the body's own immune system to clear the venom from the bloodstream.

It is important to note that anti venom is specific to the species of snake that produced the venom. This means that anti venom for one species of snake will not be effective against the venom of another species. It is also important to administer anti venom as soon as possible after a snake bite, as the venom can rapidly spread through the body and cause severe damage if left untreated.

The function of IgE antibody as mediators in allergic reactions of Type I is explained by their ability to interact both with antigen and with receptor molecules on the membrane of blood basophils and tissue mast cells. However, it is not understood how the interaction of an allergen with cell-bound IgE antibody will induce basophil (mast) cells to release a great number of biologically active substances of which some will be further discussed at this meeting, nor is it known what role the IgE-mast cell system plays in the development and control of a normal immune response.

The primary immune response can be described as the first response of our body system to a newly introduced foreign agent, while the secondary immune response is defined as an intensified immune response to this previously exposed antigen. The primary and secondary immune response is carried out by following two types of lymphocytes;

1)B-Lymphocytes: responsible for the production of antibodies in our blood. the type of antibodies is IgA. IgD, IgE, IgG, IgM.

2)T-Lymphocytes: These are mediators cell-mediated immunity.

So, the correct answer is 'Option A

"HIV " Attacks CD4 cells (T- helper, T- cells) .. this cells plays important role in immune system..

It damage our immunity system from which any bacteria or virus can affect on us it's difficult to choose one tablet

IgG immunoglobin me sabse jyada 80% paye jate h . ye sbse chote imuno globin hote h kyuki enme paratopes kevel 2 hote h upr se ye monovalant hote h. chote size ke karan ye placenta ko cross kr jate h

The person is immunised by administering performed antibodies which is artificial passive immunity

Ringworm - fungal infection AIDS- HIV virus Common cold - Rhino Virus typhoid - Salmonella typhi ( bacteria) tuberculosis - mycobacterium tuberculosis ( bacteria) dysentery - it is of two types bacterial and amoebic therefore the viral diseases are AIDS and Common cold

Thymus gland is the correct option as it is large at the time of birth but reduces to a very small size in adults.

Explanation:

Thymus gland is a specialized gland of the lymphatic system that plays an important role in the development of the immune system. It is located in the upper thorax, behind the sternum, and in front of the heart. The thymus gland is large at the time of birth and continues to grow until puberty. After puberty, the thymus gland begins to shrink and is replaced by fatty tissue. By the age of 20, the thymus gland has reduced to about one-third of its maximum size, and by the age of 50, it has reduced to only a few grams of fatty tissue.

Why is Thymus gland large at the time of birth?

The thymus gland is very active during fetal development and plays a crucial role in the development of the immune system. The thymus gland produces T-lymphocytes, which are immune cells that play a crucial role in fighting infections and diseases. The thymus gland is essential for the development of T-lymphocytes, which are responsible for recognizing and attacking foreign substances in the body. The thymus gland is particularly important during fetal development because the fetus does not have a fully developed immune system and relies on the mother's immune system for protection.

Why does Thymus gland reduce in size in adults?

The thymus gland begins to shrink after puberty because the production of T-lymphocytes decreases with age. As a result, the thymus gland is no longer required to produce large numbers of T-lymphocytes, and its function gradually declines. The thymus gland is gradually replaced by fatty tissue, which is an irreversible process. However, the T-lymphocytes that are produced by the thymus gland during fetal development and childhood continue to circulate in the body and play a crucial role in the immune system throughout life.

Explanation:
Proto-oncogenes are normal genes in cells that regulate cell growth and division. However, if these genes are mutated or activated, they can become oncogenes, which promote uncontrolled cell growth and division, leading to the development of cancer. Several proto-oncogenes have been identified in normal cells, and when activated, they can turn into oncogenes, potentially leading to the transformation of the cells into cancer cells.

The correct sequence of words to complete the paragraph is "proto-oncogenes, oncogenes." The other options presented include "oncogenes, proto-oncogenes," "cellular oncogenes, proto-oncogenes," and "cellular oncogenes, oncogenes," but none of these accurately reflect the relationship between proto-oncogenes and oncogenes.

In summary, proto-oncogenes are normal genes that can become oncogenes if they are mutated or activated. Several proto-oncogenes have been identified in normal cells, and when activated, they can turn into oncogenes, which can lead to the development of cancer.

Incorrect Immune System Component and Role Match

Explanation:
The immune system is a complex network of cells, tissues, and organs that work together to defend the body against harmful pathogens. The immune system components and their respective roles are as follows:

a) Interferons - Secreted by virus-infected cells and protect non-infected cells from further viral infection. They stimulate the production of antiviral proteins that prevent the virus from replicating in healthy cells.

b) B-lymphocytes - Produce antibodies in response to pathogens into blood to fight with them. B-lymphocytes are a type of white blood cell that recognizes and neutralizes specific pathogens by producing antibodies that bind to and destroy them.

c) Macrophages - Mucus-secreting cells that trap microbes entering in the body. This is an incorrect match as macrophages are actually white blood cells that engulf and digest foreign substances, such as bacteria and viruses, in a process called phagocytosis.

d) IgA - Present in colostrum in early days of lactation to protect infant from diseases. IgA is an antibody that is found in secretions such as tears, saliva, and breast milk. It helps to prevent pathogens from entering the body through the mucous membranes.

In conclusion, the correct match of immune system components and their respective roles is important to understand the functioning of the immune system and to develop effective strategies to combat diseases.

lgE is the most abundant antibody produced against allergens

Allergens are substances that can trigger an allergic response in individuals who are sensitive or allergic to them. When allergens enter the body, they can bind to specific antibodies called immunoglobulin E (IgE) antibodies. IgE antibodies are produced by a type of white blood cell called B cells in response to exposure to allergens. These antibodies are particularly involved in allergic reactions.

Explanation:
There are five major classes of antibodies, also known as immunoglobulins (Ig): IgA, IgD, IgE, IgG, and IgM. Each class of antibody has its own unique structure and function. Among these, IgE is the most abundant antibody produced against allergens.

Key Points:
- IgE is produced in response to allergen exposure.
- It plays a crucial role in allergic reactions by binding to allergens and triggering the release of chemicals such as histamine from mast cells and basophils.
- Histamine release leads to the typical symptoms of an allergic reaction, such as itching, swelling, redness, and increased mucus production.
- IgE antibodies are involved in allergic diseases such as allergic rhinitis (hay fever), asthma, and atopic dermatitis (eczema).
- The production of IgE antibodies is tightly regulated to prevent unnecessary allergic reactions.
- Individuals with allergies often have higher levels of IgE antibodies in their blood compared to non-allergic individuals.

Conclusion:
In summary, IgE is the most abundant antibody produced against allergens. It plays a key role in allergic reactions by binding to allergens and triggering the release of chemicals that cause allergy symptoms. Understanding the role of IgE antibodies in allergic reactions is important for the development of diagnostic tests and targeted treatments for allergies.

Yellow fever and dengue are the pair of diseases that are viral and transmitted by mosquitoes.

Yellow Fever:
- Yellow fever is a viral disease caused by the yellow fever virus.
- It is primarily transmitted by the bite of infected female mosquitoes, especially the Aedes aegypti species.
- The virus is endemic in tropical regions of Africa and Central and South America.
- Symptoms of yellow fever include fever, headache, muscle pain, jaundice, and bleeding.
- In severe cases, it can lead to organ failure and death.
- There is no specific treatment for yellow fever, but a vaccine is available for prevention.

Dengue:
- Dengue is a viral disease caused by the dengue virus.
- It is transmitted by the bite of infected female Aedes mosquitoes, primarily Aedes aegypti.
- Dengue is common in tropical and subtropical regions around the world.
- Symptoms of dengue include high fever, severe headache, joint and muscle pain, rash, and mild bleeding.
- In severe cases, it can lead to dengue hemorrhagic fever or dengue shock syndrome, which can be life-threatening.
- There is no specific treatment for dengue, but supportive care can help manage symptoms.

Viral Diseases Transmitted by Mosquitoes:
- Mosquitoes are known to transmit several viral diseases, including yellow fever, dengue fever, Zika virus, chikungunya, and West Nile virus.
- These viruses are primarily transmitted when a mosquito bites an infected person and then bites another person, transmitting the virus through its saliva.
- Mosquito-borne viral diseases are more common in tropical and subtropical regions where mosquito populations are abundant.
- The Aedes mosquitoes, particularly Aedes aegypti, are the main vectors for these viral diseases.

Conclusion:
- Among the given options, the pair of diseases that are both viral and transmitted by mosquitoes is yellow fever and dengue. Both diseases are caused by different viruses and are primarily transmitted by the bite of infected Aedes mosquitoes.

Infectious and Non-infectious Diseases

Infectious diseases are those that are caused by pathogenic microorganisms such as bacteria, viruses, fungi, and parasites. These diseases can be transmitted from one person to another through various modes of transmission such as direct contact, droplets, airborne, fecal-oral route, and vector-borne.

Non-infectious diseases are those that are not caused by pathogenic microorganisms. These diseases may have genetic, environmental, or lifestyle factors as their causes. Some examples of non-infectious diseases include cancer, diabetes, hypertension, and heart disease.

Answer Explanation

The pair that contains an infectious and a non-infectious disease respectively is option 'B', which is AIDS and cancer.

- AIDS is an infectious disease caused by the human immunodeficiency virus (HIV). It is primarily transmitted through sexual contact, blood transfusions, and vertical transmission from mother to child during pregnancy, childbirth, or breastfeeding.
- Cancer, on the other hand, is a non-infectious disease that is caused by uncontrolled growth and division of abnormal cells in the body. It can be caused by genetic mutations, exposure to environmental factors such as tobacco smoke and ultraviolet radiation, and lifestyle factors such as poor diet and lack of physical activity.

Therefore, option 'B' is the correct answer as it contains one infectious disease (AIDS) and one non-infectious disease (cancer).

Α-interferon is a biological response modifier used in cancer treatment. It activates the immune system, helping the body detect and destroy tumor cells that have evaded immune recognition.