Tag: biology

Questions Related to biology

Approximate number of AIDs patients worldwide is 

  1. 2 million

  2. 36.9 million

  3. 200 million

  4. 300 million


Correct Option: B
Explanation:
  • AIDS(acquired immunodeficiency syndrome) is caused by the HIV virus. It breaks down the body immune system, leaving the patient vulnerable to a host of life-threatening opportunistic infections.
  • The first AIDS cases were reported in the United States in June 1981.
  • Approximate number of AIDs patients worldwide is  36.9 million. Of these, 1.8 million were children (<15 years old). An estimated 1.8 million individuals worldwide became newly infected with HIV in 2017 – about 5,000 new infections per day
  • So, the correct answer is '36.9 million'.

AIDS virus enter the human body through

  1. Food

  2. Kissing

  3. Water

  4. Blood


Correct Option: D
Explanation:
  • AIDS (acquired immunodeficiency syndrome) is caused by the HIV virus. It breaks down the body immune system, leaving the patient vulnerable to a host of life-threatening opportunistic infections.
  • AIDS does not spread from person to person through direct contact (touching a person who has the infection or kissing), indirect contact (touching a contaminated object or food), or droplet contact (inhaling droplets made when a person who has the infection coughs, sneezes, or talks). 
  • AIDS virus(HIV) enters the human body through blood when wrongly transfused from an AIDS infected patient or usage of needles and syringes of the AIDS infected person.
  • So, the correct answer is 'Blood'.

Choose the wrong statement.

  1. Time lag between infection and appearance of AIDS is a few hours to a week.

  2. The genetic material of HIV is RNA.
  3. HIV replicates in T$ _4$ lymphocytes.

  4. ARV drugs are only partially effective in AIDS treatment.

  5. HIV spreads through sexual contact and sharing a needle and not by a mere touch or physical contact.


Correct Option: A
Explanation:

Human immunodeficiency virus infection or acquired immune deficiency syndrome (HIV/AIDS) is a serious immune disorder caused by infection with the human immunodeficiency virus (HIV). HIV is different in structure from other retroviruses. It is composed of two copies of positive-sense single-stranded RNA. HIV replicates in T4 cells. AIDS is a sexually transmitted infection and transmitted through sexual contact and sharing infected needles. It is not spread by mere touch or physical contact. There is currently no cure or effective HIV vaccine. Treatment consists of highly active antiretroviral therapy which slows progression of the disease. HIV usually causes flu-like symptoms about two to four weeks after transmission. This short period of time is called acute infection.

So, the correct answer is 'Time lag between infection and appearance of AIDS is a few hours to a week'.

Which of the following statements is correct with respect to AIDS ?

  1. Drug addicts are least susceptible to HIV infection.

  2. AIDS patients are being fully cured cent percent with proper care and nutrition.

  3. The causative HIV retroviruses enters helper T-lymphocytes thus reducing their number.

  4. HIV can be transmitted through eating food together with an infected person.


Correct Option: C
Explanation:
  • AIDS (acquired immunodeficiency syndrome) is caused by the HIV virus.
  • T-helper cells play an important role in adaptive immunity. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
  • HIV destroys(CD4+ cells) T-helper lymphocyte cells and reducing their number. They're responsible for keeping you healthy from common diseases and infections. As HIV gradually weakens your natural defences, signs and symptoms will occur.
  • Hence HIV attacks T-helper cells.
  • So, the correct answer is 'The causative HIV retroviruses enters helper T-lymphocytes thus reducing their number.'.

AIDS virus has 

  1. Single strand DNA

  2. Double strand DNA

  3. Single strand RNA

  4. Double strand RNA


Correct Option: C
Explanation:
  • AIDS (acquired immunodeficiency syndrome) is caused by the HIV virus. It breaks down the body immune system, leaving the patient vulnerable to a host of life-threatening opportunistic infections.
  • HIV (Human immunodeficiency virus)belongs to the special class of viruses called retrovirus.with in this class HIV is placed in a subgroup called lentivirus.
  • HIV consists of a viral envelope.with in the viral envelope 2 identical copies of single-stranded RNA are a present and reverse transcriptase enzyme.
  • Hence AIDS virus has single-stranded RNA.
  • So, the correct answer is 'Single-stranded RNA'.

Choose the wrong statement regarding AIDS

  1. It is an immunodeficiency diease

  2. It is an caused by retrovirus HIV

  3. HIV selectively infects and kills B-lymphocytes

  4. Genome RNA replicates via DNA intermediate

  5. Viral RNA genome is converted into copy DNA by reserve transcriptasea


Correct Option: C
Explanation:
  • AIDS(acquired immunodeficiency syndrome) is caused by the HIV virus(retrovirus). It breaks down the body immune system, leaving the patient vulnerable to a host of life-threatening opportunistic infections.
  • HIV destroys(CD4+ cells) T-helper cells.They're responsible for keeping you healthy from common diseases and infections. As HIV gradually weakens your natural defences, signs and symptoms will occur. Hence HIV selectively infects and kills T-lymphocytes.
  • So, the correct answer is 'Option C'.

At which stage of HIV infection does one usually show symptoms of AIDS

  1. When infective retro-virus enters in host cells.

  2. When HIV damages large number of helper T-lymphocytes.

  3. When the viral DNA is produced by reverse transcription.

  4. Within 15 days of sexual contact with an infected person.


Correct Option: B
Explanation:

After entering into the body of a person, HIV enters into macrophages, where RNA genome of the virus replicates to produce viral DNA with the help of enzyme reverse transcriptase which gets incorporated into host cell's DNA and directs the cells to produce virus particles. Macrophages continue to produce viruses. Simultaneously, HIV enters into helper T- lymphocytes, replicates and produce more viruses which are released in blood and they attack other lymphocytes causing repeated decrease in T- lymphocytes. Due to this person starts suffering from infections that could have been otherwise overcome. So the correct option is "when HIV damages large number of helper T- lymphocytes"   

In AIDS patient, a reduction of 10% weight indicates

  1. ARC

  2. Acute infections stage

  3. Symptomatic stage

  4. Nonsymptomatic stage


Correct Option: A
Explanation:

AIDS-related complex (ARC) is a phase of HIV infection described clinically but no longer commonly diagnosed in practice. ARC lacks only the opportunistic infections and neoplasms which define AIDS. ARC patients usually show symptoms of fatigue, weight loss upto 10%, night sweats, along with superficial fungal infections of the mouth and fingernails and toenails.

So, the correct answer is 'ARC'.

Which of the following is correct regarding AIDS causative agent HIV?

  1. HIV is enveloped virus containing one molecule of single-stranded RNA and one molecule of reverse transcriptase

  2. HIV is enveloped virus that contains two identical molecules of single-stranded RNA and two molecules of reverse transcriptase

  3. HIV is unenveloped retrovirus

  4. HIV does not escape but attacks the acquired immune response


Correct Option: B
Explanation:

AIDS is caused by HIV (Human Immuno Deficiency Virus). HIV is a member of a group of the retrovirus. Retrovirus has envelope enclosing the RNA genome. HIV is enveloped virus that contains two identical molecules of single-stranded RNA and two molecules of reverse transcriptase.

So the correct option is 'HIV is enveloped virus that contains two identical molecules of single-stranded RNA and two molecules of reverse transcriptase'.

Which of the following is an example of acquired disease:

  1. Albinism

  2. AIDS

  3. Cat Eye syndrome

  4. Down syndrome


Correct Option: B
Explanation:

Explanation: An acquired disorder is a medical condition which develops post-fetally; in contrast with a congenital disorder, which is present at birth. A congenital disorder may be antecedent to an acquired disorder.