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Q1Science·Disease, Immunity and Public HealthPYQ 2023
'Wolbachia method' is sometimes talked about with reference to which one of the following?
- AControlling the viral diseases spread by mosquitoesCorrect
- BConverting crop residues into packing material
- CProducing biodegradable plastics
- DProducing biochar from thermo-chemical conversion of biomass
Explanation
Correct. Wolbachia are intracellular bacteria introduced into Aedes aegypti mosquitoes to reduce their ability to transmit dengue, Zika, and chikungunya viruses.
Q2Science·Disease, Immunity and Public HealthPYQ 2021
In the context of hereditary diseases, consider the following statements:
1. Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilisation of the egg.
2. A child inherits mitochondrial diseases entirely from mother and not from father.
Which of the statements given above is/are correct?
- A1 only
- B2 only
- CBoth 1 and 2Correct
- DNeither 1 nor 2
Explanation
Correct. Mitochondrial replacement therapy prevents passage of defective mitochondria, and mitochondrial DNA is inherited maternally since mitochondria in sperm are destroyed after fertilisation.
Q3Science·Disease, Immunity and Public HealthPYQ 2019
Which one of the following statements is not correct?
- AHepatitis B virus is transmitted much like HIV.
- BHepatitis B, unlike Hepatitis C, does not have a vaccine.Correct
- CGlobally, the number of people infected with Hepatitis B and C viruses are several times more than those infected with HIV.
- DSome of those infected with Hepatitis B and C viruses do not show the symptoms for many years.
Explanation
Correct (not correct statement). Hepatitis B does have a highly effective vaccine; it is Hepatitis C that currently lacks a vaccine.
Q4Science·Disease, Immunity and Public HealthPYQ 2017
Consider the following statements:
1. In tropical regions, Zika virus disease is transmitted by the same mosquito that transmits dengue.
2. Sexual transmission of Zika virus disease is possible.
Which of the statements given above is/are correct?
- A1 only
- B2 only
- CBoth 1 and 2Correct
- DNeither 1 nor 2
Explanation
Correct. Aedes aegypti is the primary vector for both Zika and dengue in the tropics, and Zika can also spread through sexual contact.
Q5Science·Disease, Immunity and Public HealthPYQ 2015
H1N1 virus is sometimes mentioned in the news with reference to which one of the following diseases?
- AAIDS
- BBird flu
- CDengue
- DSwine fluCorrect
Explanation
Correct. H1N1 is the influenza A subtype responsible for swine flu, which caused the 2009 global pandemic.
Q6Science·Disease, Immunity and Public HealthPYQ 2014
Consider the following diseases:
1. Diphtheria
2. Chickenpox
3. Smallpox
Which of the above diseases has/have been eradicated in India?
- A1 and 2 only
- B3 onlyCorrect
- C1, 2 and 3
- DNone
Explanation
Correct. Smallpox was declared eradicated globally in 1980 by WHO; India's last case was in 1975. Diphtheria and chickenpox remain endemic.
Q7Science·Disease, Immunity and Public HealthPYQ 2014
Consider the following pairs:
Vitamin — Deficiency disease
1. Vitamin C — Scurvy
2. Vitamin D — Rickets
3. Vitamin E — Night blindness
Which of the pairs given above is/are correctly matched?
- A1 and 2 onlyCorrect
- B3 only
- C1, 2 and 3
- DNone
Explanation
Correct. Vitamin C deficiency causes scurvy and Vitamin D deficiency causes rickets; Vitamin E deficiency causes neurological problems, not night blindness.
Q8Science·Disease, Immunity and Public HealthPYQ 2013
Which of the following diseases can be transmitted from one person to another through transfusion of blood?
1. Chikungunya
2. Hepatitis B
3. HIV-AIDS
Select the correct answer using the codes given below.
- A1 only
- B2 and 3 onlyCorrect
- C1 and 3 only
- D1, 2 and 3
Explanation
Correct. Hepatitis B and HIV are well-known blood-borne infections that can transmit through transfusion; chikungunya, though a viraemic infection, is not a standard transfusion-transmitted disease.
Q9Science·Disease, Immunity and Public HealthPYQ 2010
Widespread resistance of malarial parasites to drugs like chloroquine has prompted attempts to develop a malaria vaccine to combat malaria. Why is it difficult to develop an effective malaria vaccine?
- AMalaria is caused by several species of Plasmodium.Correct
- BMan does not develop immunity to malaria during natural infection.
- CVaccines can be developed only against bacteria.
- DMan is only an intermediate host and not the definitive host.
Explanation
Correct. Multiple Plasmodium species (P. falciparum, P. vivax, P. malariae, P. ovale) with antigenic variation make it extremely difficult to design a single effective vaccine.
Q10Science·Disease, Immunity and Public HealthPYQ 2010
With regard to the transmission of the Human Immunodeficiency Virus, which one of the following statements is not correct?
- AThe chances of transmission from female to male are twice as likely as from male to female.Correct
- BThe chances of transmission are more if a person suffers from other sexually transmitted infections.
- CAn infected mother can transmit the infection during pregnancy, at childbirth and by breastfeeding.
- DThe risk of contracting infection from transfusion of infected blood is much higher than an exposure to contaminated needle.
Explanation
Correct (not correct statement). Epidemiological data shows that male-to-female transmission is actually more likely due to greater mucosal exposure, not the reverse.
Q11Science·Disease, Immunity and Public HealthPYQ 1999
Which one of the following genetic diseases is sex-linked?
- ARoyal haemophiliaCorrect
- BTay-Sachs disease
- CCystic fibrosis
- DHypertension
Explanation
Correct. Royal haemophilia (Haemophilia B) is an X-linked recessive disorder famously traced through European royal families from Queen Victoria.
Q12Science·Disease, Immunity and Public HealthPYQ 1996
AIDS is transmitted:
I. By sexual contact.
II. By blood transfusion.
III. By mosquitoes and other blood sucking insects.
IV. Across the placenta.
Of these statements
- AI, II and III are correct
- BI, II and IV are correctCorrect
- CI, III and IV are correct
- DI and III are correct
Explanation
Correct. HIV transmits through sexual contact (I), blood transfusion (II), and across the placenta from mother to child (IV); mosquitoes cannot transmit HIV.