Biology · General Awareness

Disease Vectors and Pathogens

820 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 organisms causes malignant malaria?

  1. Plasmodium malariae

  2. Plasmodium vivax

  3. Plasmodium ovale

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

Plasmodium falciparum causes malignant tertian malaria (falciparum malaria), the most severe and life-threatening form. P. vivax causes vivax malaria (benign tertian), P. malariae causes quartan malaria, and P. ovale causes ovale malaria (mild tertian). Only P. falciparum is termed 'malignant' malaria.

Multiple choice

IgE levels are high in infections with

  1. Trichinella spiralis

  2. Trypanosoma cruzi

  3. Trypanosoma rhodesiense

  4. Plasmodium falciparum

  5. Leishmania tropica
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Parasites like Trichinella frequently increase the IgE levels, usually polyclonally. This tends to inhibit the protective effect of IgE by diluting out the specific IgE on the mast cell. Inflammation induced by mast cell degranulation leads to influx of IgG, which causes damage to the parasite.

Multiple choice

Other than spreading malaria, anopheles mosquitoes are also vectors of

  1. encephalitis

  2. dengue fever

  3. yellow fever

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

It is a serious concern that malaria can go on to spread far and wide because when an anopheles is contaminated with malaria, it stays within it for life and this infects all those that it bites. It is found that the malaria infected anopheles mosquito has more appetite than an uninfected mosquito. This makes the potential spread of malaria. Other than spreading malaria, anopheles mosquitoes are also vectors of filariasis, which is a disease caused by nematodes in the blood or tissues of the body causing blockage of lymphatic vessels.

Multiple choice

__________ are facultative parasites.

  1. Pinnotheresostreum and Muicobacterium tuberculosis

  2. Entamoeba hystolytica and Ascaris lumbicoids

  3. Fasciola hepatica and Pinnotheres ostreum

  4. Ascaris lumbicoids and Muicobacterium tuberculosis

  5. Fasciola hepatica and Entamoeba hystolytica
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Organisms which may be parasitic or free living at will, i.e., can live as free living forms in absence of a host are called facultative parasites. Examples: Pinnotheres ostreum and Muicobacterium tuberculosis

Multiple choice

Which of the following matches of ‘Disease – causative agent – vector’ is correct?

  1. African sleeping sickness – Trypanosoma cruzi – Tse-tse fly

  2. Kala Azar – Leishmania donovani – Sand fly

  3. Malaria – Plasmodium sp. – female Culex mosquito

  4. Filariasis – Wuchreria bancrofti – female Anopheles mosquito

  5. Chaga’s disease – Trypanosoma gambiense – Tse-tse fly
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Kala Azar is caused by Leishmania donovani. Vector: Sand fly

Multiple choice

Which one of the following will not suffer from malaria?

  1. HbAHbS

  2. HbAHbA

  3. HbSHbS

  4. Both HbAHbS and HbAHbA

  5. Both HbAHbS and HbSHbS
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

It represents carrier and does not suffer from malaria because RBC being sickle shaped, malarial parasite plasmodium vivax cannot penetrate into RBC.

Multiple choice

Match the following: Names of parasitic nematodes|Diseases| |a. Ascaris|1. Elephantiasis| |b. Wuchereria bancrofti|2. Ascariasis| |c. Enterobius|3. Enterobiasis|

  1. a - 2, b - 1, c - 3

  2. a - 2, b - 3, c - 1

  3. a - 3, b - 2, c - 1

  4. a - 1, b - 2, c - 3

  5. a - 3, b - 1, c - 2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 Parasitic nematode Ascaris causes ascariasis disease. Parasitic nematode Wuchereria bancrofti causes elephantiasis. Parasitic nematode Enterobius causes enterobiasis.

Multiple choice

Which of the following are correct regarding Entamoeba histolytica? P. Digenetic life cycle Q. Trophozoite is adult and harmful stage R. Causes amoebic dysentery in humans S. Reserve food material is starch Select the correct option using codes given below:

  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

The adult and harmful stage of Entamoeba histolytica is called trophozoite. Entamoeba histolytica causes amoebic dysentery in humans.

Multiple choice

Life cycle of which of the following pathogenic protozoans is/are digenetic?

  1. Entamoeba histolytica

  2. Plasmodium vivax

  3. Trypanosam cruzi

Select the correct answer using codes given below:

  1. 1 only

  2. Both 1 and 2

  3. Both 1 and 3

  4. Both 2 and 3

  5. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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). Trypanosam cruzi possesses a digenetic life cycle involving a hematophagous insect vector and a mammalian host.

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 secondary host

R. Reserve food material is in the form of glycogen

S. Reproduce sexually as well as asexually

Select the correct answer using codes given below:

  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 reproduce 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. The female Anopheles mosquito serves as a reservoir host for Plasmodium.

R. The gametophytes of Plasmodium are formed in lumen of stomach of mosquito.

S. The zygote of Plasmodium is known as ookinete.

Select the correct answer using codes given below:

  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

Monkeys serve as reservoir host for Plasmodium. Female Anopheles mosquito serves as vector. Gametophytes of Plasmodium are formed in RBC of blood of man. Gametes are formed in lumen of stomach of mosquito.