Tag: aids to health

Questions Related to aids to health

Match the columns and find the correct option

   LIST I   LIST II 
 a  Natural active immunity  i  Develops due to to vaccinaton
 b  Natural passive immunity  ii  Antirabies serum 
 c  Artificial active immunity  iii  Acquired after smallpox infection 
 d  Artificial passive immunity  iv  Transferred from mother to child
  1. a - iv, b - iii, c - i, d - ii

  2. a - iii, b - i, c - iv, d - ii

  3. a - iii, b - iv, c - i, d - ii

  4. a - iii, b - iv, c - ii, d - i


Correct Option: C
Explanation:
  • Naturally acquired active immunity occurs when a person is exposed to a live pathogen and develops a primary immune response. An example is acquired after smallpox infection.
  •  Naturally acquired passive immunity occurs during pregnancy, in which certain antibodies are passed from the maternal blood into the fetal bloodstream in the form of IgG.
  • Artificially acquired active immunity can be induced by a vaccine, a substance that contains antigen. An example of artificial active immunity is building up a resistance to a disease due to immunization.
  •  Artificially acquired passive immunity is a short-term immunization by the injection of antibodies, such as gamma globulin, that is not produced by the recipient's cells. eg: Antirabies serum,
  •  So, the correct answer is 'a - iii, b - iv, ci, d - ii'.

Body cells infected by viruses are destroyed mostly by 

  1. IgA

  2. Phagocytes

  3. Natural antibodies

  4. Natural Killer cells


Correct Option: D
Explanation:
  • Immunity to viral infection is caused by a variety of specific and nonspecific mechanisms. 
  • The activation of different immune functions and the duration and magnitude of the immune response depending on how the virus interacts with host cells. 
  •  Cytotoxic T lymphocytes, natural killer (NK) cells and antiviral macrophages can recognize and kill virus-infected cells.
  •  Hence, Body cells infected by viruses are destroyed mostly by Natural Killer cells.
  • So, the correct answer is 'Natural Killer cells'.

Short lived immunity acquired from mother to foetus across the placenta or through mother's milk to the infant is categorised  as 

  1. Active immunity

  2. Passive immunity

  3. CMI

  4. Auto immunity

  5. Innate immunity


Correct Option: B
Explanation:

Passive immunity is the transfer of active humoral immunity of ready-made antibodies. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta and through colostrum (mother's milk), and it can also be induced artificially, when high levels of antibodies specific to a pathogen or toxin (obtained from animals) are transferred to non-immune persons through blood products that contain antibodies. Passive immunity is short lived.

So, the correct answer is 'Passive immunity'.

The cytokine barrier among these is 

  1. Polymorphonuclear neutrophil

  2. Monocyte

  3. NK cells

  4. Interferon

  5. Macrophage


Correct Option: D
Explanation:

  • Cytokine inhibits viral replication.
  • They form an innate immune system by forming physical barriers. 
  •  Virus-infected cells secrete proteins called interferons which protect non-infected cells from a further viral infection is a cytokine barrier. Hence, The cytokine barrier among these is interferon.
Sp, the correct answer is 'interferon'.

A person was saved from poisonous snake bite by antivenom injection . Which of the following immunity explain this form of protection ?

  1. Naturally acquired active immunity

  2. Artificially acquired active immunity

  3. Naturally acquired passive immunity

  4. Artificially acquire passive immunity


Correct Option: D
Explanation:

Artificially acquired passive immunity explains this form of protection. When performed antibodies are directly injected into the body, it is known as artificial passive immunity. It provides the quick immune response. In case of snake bites, the injection which is given to the patients, contain performed antibodies against snake venom. This type of immunisation is passive immunisation.

Passive actively acquired immunity can be activated by all except.

  1. Attenuated microorganism

  2. Through hyper immune serum

  3. Through convalescent serum

  4. Through pooled gamma-globulin


Correct Option: A
Read the passage and answer the following question.

The genes that code for the human leukocyte antigen(HLA) antigens, also known as the major histocompatibility complex(MHC) genes, are all located on human chromosome $6$. Two brothers and a sister participated in a bone marrow donor registration, and their HLA typing results are given.


ID HLA-A HLA-B HLA-C HLA-DR
$1$ A$1$, A$3$ B$5$, B$7$ C$3$, Cw$19$ DR$3$, DR$9$
$2$ A$1$, A$6$ B$2$, B$6$ C$2$, C$16$ DR$4$, DR$13$
$3$ A$1$, A$6$ B$2$, B$6$ C$2$, C$16$ DR$4$, DR$13$


What is your explanation for the single HLA-A result for sibling $3$?

  1. A gene-deletion event occured during crossing over

  2. Nondisjunction occurred during meiosis

  3. A laboratory error caused the lost data; it should have a second result

  4. A metabolic error prevented the synthesis of the second antigen

  5. Both the parents were heterozygous for HLA-A$1$


Correct Option: E
Explanation:

HLA is inherited as a "set" of the three HLA groups, A, B, DR known as halotype. In given halotype of sibling 3, all four HLAs (HLA-A, B , C and DR) are different refecting the heterozygosity of two parents for the same. The sibling has HLA of two types: A1 and A6 i.e. one parent have HLA-A1 and other has HLA-A6. Both parents are heterozygous for HLA-A. Thus, the correct answer is option E.

Read the passage and answer the following question.
Many mammalian cell membrane receptors associated with the immune system contain repetitive structures known as the immunoglobulin fold. Receptors containing even one of these folds are considered members of the immunoglobulin superfamily. 
Which of the following explains this common feature in different molecules?
  1. All of the genes that produce these proteins used to be part of a much larger gene that fragmented in the past

  2. All of the genes in question are retrotransposons

  3. Most of the genes in question are introns that experienced mutations that removed the splice sequence

  4. The fold was so successful as a signaling molecule that it encouraged its propagation

  5. The fold is repetitive because of gene duplication


Correct Option: E
Explanation:

Repetitive gene products are produced by gene duplication. A duplicated gene produces the same protein in multiple repeats. Retrotransposons can amplify themselves but are not necessarily present in multiple copies at the same chromosomal location. Introns are noncoding sequences. Proteins are encoded by genes only; they are not a product of encouraged propagation caused by relative success in the functioning. So, the correct answer is option E.

Read the passage and answer the following question.

The genes that code for the human leukocyte antigen(HLA) antigens, also known as the major histocompatibility complex(MHC) genes, are all located on human chromosome $6$. Two brothers and a sister participated in a bone marrow donor registration, and their HLA typing results are given.


ID HLA-A HLA-B HLA-C HLA-DR
$1$ A$1$, A$3$ B$5$, B$7$ C$3$, Cw$19$ DR$3$, DR$9$
$2$ A$1$, A$6$ B$2$, B$6$ C$2$, C$16$ DR$4$, DR$13$
$3$ A$1$, A$6$ B$2$, B$6$ C$2$, C$16$ DR$4$, DR$13$


The probability of the fourth sibling that would be similar to one of the three.

  1. $25$ percent

  2. $100$ percent

  3. $0$ percent

  4. $50$ percent

  5. $75$ percent


Correct Option: E

Consider the following statements about phagocytes in man. 
1) They provide the second line of defense. 
2) They can recognize and distinguish between self and non-self. 
3) They have antigen receptor.
Which of the above statements are true?

  1. Only 1 and 2

  2. Only 1 and 3

  3. Only 2 and 3

  4. All are true


Correct Option: B
Explanation:

Phagocytes are the type of cells present inside the body capable of engulfing bacteria and other small cells in the body and provide second line defense. It means that they destroy invaders in a generalized way and activate via antigen receptors that bind to an antibody attached to antigen without recognizing between self and non-self.

So the correct option is "Only 1 and 3".