Biology · General Awareness

Disease Vectors and Pathogens

844 Questions

Disease vectors and pathogens examine how organisms like Plasmodium and Leishmania transmit infections. Test items require matching vectors to specific diseases. Studying these life cycles is essential for scoring well.

Plasmodium infective stagesDisease transmission modesDisease vectors and fleasIntracellular parasitesElephantiasis causes

Disease Vectors and Pathogens Questions

Multiple choice

Which of the following diseases is a protozoan disease?

  1. Rabies

  2. AIDS

  3. Malaria

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

Malaria is caused by Plasmodium, which is a protozoan (single-celled eukaryotic organism). It is transmitted by female Anopheles mosquito. Rabies and AIDS are caused by viruses (rabies virus and HIV respectively), while Anaemia is not a disease but a condition characterized by low hemoglobin.

Multiple choice

Which of the following organisms transmits virus that causes dengue?

  1. Anopheles

  2. Aedes

  3. Tick

  4. Dog
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Aedes mosquito (specifically Aedes aegypti) is the primary vector that transmits the dengue virus. Female Aedes mosquitoes become infected when they bite an infected person and can then transmit the virus to other people. Anopheles transmits malaria, ticks transmit Lyme disease, and dogs transmit rabies virus.

Multiple choice

Which of the following organisms is the carrier of malaria causing protozoan?

  1. Entamoeba

  2. Mosquito

  3. Housefly

  4. Dog
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Malaria is caused by the protozoan Plasmodium, which requires a vector to complete its life cycle and transmit between humans. The female Anopheles mosquito serves as this carrier (vector) - when it bites an infected person, it takes up Plasmodium gametocytes, which develop in its gut and are later injected into a new host during another blood meal. Entamoeba causes dysentery, houseflies spread mechanical contamination, and dogs carry rabies virus.

Multiple choice

Which of the following microorganisms causes malaria?

  1. Plasmodium

  2. Anopheles

  3. Entamoeba

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

Malaria is caused by protozoan parasites of the genus Plasmodium (P. falciparum, P. vivax, P. ovale, P. malariae). These parasites infect red blood cells and cause the characteristic fever cycles, anemia, and complications of malaria. Anopheles is the mosquito genus that transmits Plasmodium but does not cause malaria itself. Entamoeba causes dysentery, and Rhizopus is a fungus that causes mucormycosis.

Multiple choice

Which of the following organisms causes ‘elephantiasis’ in humans?

  1. Ascaris

  2. Spongilla

  3. Liver fluke

  4. Wuchereria
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Wuchereria bancrofti is the parasitic nematode worm that causes elephantiasis (lymphatic filariasis) in humans. It is transmitted by mosquito vectors and causes lymph vessel blockage leading to massive swelling. Ascaris causes ascariasis, Spongilla is a freshwater sponge, and Liver fluke causes liver disease.

Multiple choice

Match the following diseases with their causative agent and vectors.

   
Disease Causative agent Vector
P. Kala azar i. Plasmodium spp. 1. Tse-tse fly
Q. African sleeping sickness ii. Leishmania donovani 2. Sand fly
R. Epidemic typhus iii. Trypanosoma brucei 3. Mosquito
S. Malaria iv. Rickettsia prowazekii 4. Body louse

  1. P - ii - 3, Q - iv - 1, R - i - 2, S - iii - 4

  2. P - iii - 1, Q - iv - 2, R - ii - 4, S - i - 3

  3. P - i - 2, Q - ii - 4, R - iii - 2, S - iv - 3

  4. P - ii - 2, Q - iii - 1, R - iv - 4, S - i - 3

  5. P - i - 4, Q - iii - 1, R - ii - 3, S - iv - 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This option is wrong because all are correctly matched. Kala azar is caused by Leishmania donovani and transmitted by the bite of the sand fly. African Trypanosomiasis (also known as sleeping sickness) is caused by Trypanosoma brucei and transmitted by the tse-tse fly. Epidemic typhus is caused by Rickettsia prowazekii and transmitted by the human body louse (Pediculus humanus corporis). Malaria is a mosquito-borne infectious disease of humans and other animals caused by parasites of the Plasmodium spp.

Multiple choice

Which of the following statements are true regarding 'Trypanosoma gambiense'?

P. Endoparasite of blood and cerebrospinal fluid of man Q. Tse-tse fly acts as a secondary host R. Reserves food material in the form of glycogen S. Reproduces sexually as well as asexually

  1. P and Q

  2. P and S

  3. Q and R

  4. Q and S

  5. R and S
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Reserve food material of Trypanosoma gambiense is in the form of volutin granules. Trypanosoma gambiense reproduces only asexually by binary fission.

Multiple choice

Which of the following statements are false regarding Plasmodium?

P. It is commonly known as malarial parasite. Q. Female Anopheles mosquito serves as a reservoir host for Plasmodium. R. Gametophytes of Plasmodium are formed in the lumen of stomach of a mosquito. S. Zygote of Plasmodium is known as ookinete.

  1. P and Q

  2. P and R

  3. P and S

  4. Q and R

  5. R and S
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This option is correct because monkeys serve as a reservoir host for Plasmodium. Female Anopheles mosquito serves as a vector. Gametophytes of Plasmodium are formed in the RBC of blood of man. Gametes are formed in the lumen of stomach of a mosquito.

Multiple choice

Life cycle(s) of which of the following pathogenic protozoa is/are digenetic?

  1. Entamoeba histolytica
  2. Plasmodium vivax
  3. Trypanosam cruzi

  1. Only 1

  2. Only 2

  3. Only 3

  4. 1 and 2

  5. 2 and 3
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This option is correct because Plasmodium vivax (malaria parasite) completes its asexual part of life cycle in people and the sexual part in the female Anopheles mosquito (digenetic life cycle) and Trypanosam cruzi possesses a digenetic life cycle, involving a hematophagous insect vector and a mammalian host.