The 'Widal test' is a diagnostic test used to detect the presence of antibodies against the causative agent of: MCQ with Answer and Explanation

Question

Share Report Error

The 'Widal test' is a diagnostic test used to detect the presence of antibodies against the causative agent of:

A. Malaria

B. Typhoid fever

C. Dengue

D. Tuberculosis

Answer: Option B

Solution (By JKSSB Mock Tests)

The Widal test is a serological agglutination test used to diagnose enteric (typhoid) fever, caused by Salmonella enterica serotype Typhi. It detects the presence of specific antibodies (O and H antigens) in the patient's serum against the O (somatic) and H (flagellar) antigens of the Salmonella typhi bacteria. A significant rise in antibody titer indicates an active or recent infection. It is not used for TB (Mantoux test), malaria (blood smear), or dengue (NS1/IgM).

This question belongs to: Science Biology

Request complete Subject PDF

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Biology Questions

Question #1

Share Report

Which of the following is a recognized biodiversity hotspot in India?

A. Thar Desert

B. Deccan Plateau

C. Indo-Gangetic Plains

D. Western Ghats

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option D

Explanation:
Biodiversity hotspots are biogeographic regions with high levels of species richness and endemism that are under threat. The Western Ghats and Sri Lanka, along with the Himalayas, are recognized biodiversity hotspots in India. They harbor a vast array of flora and fauna, many of which are found nowhere else in the world, due to their unique geographical and climatic conditions.

This question belongs to: Science Biology

Question #2

Share Report

The blood vessel that carries oxygenated blood from the placenta to the fetus is the:

A. Umbilical vein

B. Pulmonary artery

C. Umbilical artery

D. Aorta

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
The umbilical vein carries oxygen-rich and nutrient-rich blood from the placenta to the fetal circulation. The two umbilical arteries carry deoxygenated blood and waste from the fetus to the placenta. In the adult, veins typically carry deoxygenated blood, but umbilical vein is an exception.

This question belongs to: Science Biology

Question #3

Share Report

The structure of DNA was described as a double helix by:

A. Mendel and Morgan

B. Darwin and Wallace

C. Schrödinger and Heisenberg

D. Watson and Crick

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option D

Explanation:
The double helix structure of DNA was proposed by James Watson and Francis Crick in 1953, based on X-ray diffraction data produced by Rosalind Franklin and Maurice Wilkins. They proposed that DNA consists of two antiparallel polynucleotide chains coiled around a common axis, with specific base pairing (A-T, G-C) holding the strands together.

This question belongs to: Science Biology

Explore All Biology MCQs