Biology · Science General

Disease Causative Agents

2,258 Questions

Disease causative agents questions test your understanding of viral, bacterial, and fungal infections, along with their transmission methods. These are common topics in general science sections of SSC and railways exams. Practice these questions to accurately identify disease pathogens and symptoms.

Viral diseasesFoodborne illnessesDisease transmission methodsExtrinsic disease factorsCommon pathogens

Disease Causative Agents Questions

Multiple choice

Strep Throat is caused by what type of bacteria?

  1. Streptococcal

  2. Staphlococcus

  3. Treponema

  4. Salmonella
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Strep throat is caused by Streptococcus bacteria. The other options are different genera of bacteria that cause unrelated illnesses.

Multiple choice

Organisms that cause human disease are typically

  1. mesophiles

  2. psychrophiles

  3. barophiles

  4. hyperthermophiles
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mesophiles are organisms that grow best at moderate temperatures, typically between 20 and 45 degrees Celsius, which includes the human body temperature.

Multiple choice

The Bubonic plague was spread by _______.

  1. rats infested with fleas carrying the bacterium.

  2. poisoned water from the town wells.

  3. an overall drop in temperatures known as a “little ice age.”

  4. the Great Famine.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Bubonic Plague was transmitted by fleas that lived on rats; these fleas carried the bacterium Yersinia pestis and spread it to humans.

Multiple choice

Which of the following is least likely to cause disease?

  1. algae

  2. viruse

  3. bacteria

  4. protozoa
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Algae are primarily aquatic photosynthetic organisms that rarely cause human diseases. In contrast, viruses, bacteria, and protozoa include many well-known pathogens responsible for illnesses ranging from colds to malaria. Note: option B has a typo (viruse should be virus).

Multiple choice

which one of the following is not a water borne disease?

  1. cholera

  2. malaria

  3. chicken pox

  4. giardia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cholera, malaria (vector-borne, but often associated with water), and giardia are commonly linked to water. Chicken pox is a viral disease spread primarily through respiratory droplets or contact, not water.

Multiple choice

With less helpful bacteria....

  1. Living things just get sick

  2. Harmful bacteria can move in and create more

  3. Living things are just healthy

  4. Living things cannot survive
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Helpful bacteria often occupy niches that prevent harmful bacteria from colonizing. When helpful bacteria are reduced, harmful bacteria have more space and resources to multiply.

Multiple choice

Bacteria can make humans healthy and sick.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bacteria are diverse; some are pathogenic (causing disease), while others are beneficial (such as those in the gut microbiome that aid digestion).

Multiple choice

Anthrax is caused by

  1. Lactobacillus

  2. Rhizobium

  3. Bacillus anthracis

  4. E .coli
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Anthrax is a serious infectious disease caused by the bacterium Bacillus anthracis. The other options are either beneficial bacteria or different types of organisms.

Multiple choice

Small pox is a

  1. Viral desease

  2. Bacterial desease

  3. Protozoal desease

  4. All of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Smallpox is a highly contagious disease caused by the variola virus. It is a classic example of a viral disease.

Multiple choice evs contaminated water spreads disease mosquitoes and malaria diseases caused by mosquitoes water borne diseases

Black-foot disease is caused due to groundwater contaminated with the excess amount of

  1. Nitrate

  2. Fluoride

  3. Arsenic

  4. Sulphur

  5. Mercury
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Arsenic comes from bedrock as well as surface leaching. Chronic exposure leads to repeated diarrhoea, peripheral neuritis, hyperkeratosis, transverse striations on fingernails, peripheral vascular insufficiency, vasospasm, hyperpigmentation leading to 'Black Foot Disease', lung inflammation, skin and lung cancer.

Multiple choice evs contaminated water spreads disease mosquitoes and malaria diseases caused by mosquitoes water borne diseases

A disease can spread from one person to population by

  1. Improper sanitation in public places.

  2. Improper sanitation in home.

  3. Sharing of food.

  4. Sharing of water bottle.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • A disease can spread from one person to population by improper sanitation in public places because many disease-causing organisms can survive on the surface of the improperly sanitized public toilet seat, and for an infection to occur, the germs(bacteria, virus) would have to be transferred from the toilet seat to your urethral or genital tract, or through a cut or sore on the buttocks or thighs, which is possible.
  • Hence A disease can spread from one person to population by improper sanitation in public places.
  • So, the correct answer is 'improper sanitation in public places'.