Biology Multiple Choice Questions on “Protozoan Diseases in Humans”.
1. Entamoeba histolytica causes _________
a) dysentery
b) elephantiasis
c) small Pox
d) mumps
Answer: a
Clarification: Entamoeba histolytica is a pathogen which causes Amoebic Dysentery. Wuchereria bancrofti, Variola virus and Paramyxo virus cause Elephantiasis, Small Pox and Mumps respectively.
2. Entamoeba histolytica is found in _________
a) Stomach
b) Brain
c) Small Intestine
d) Large Intestine
Answer: d
Clarification: Entamoeba histolytica causes Amoebic Dysentery or Amoebiasis in the large intestine of humans. Its symptoms include constipation, abdominal pain, cramps and stools with excess mucus and blood clots.
3. The pathogen causing Amoebiasis is transmitted through which of the following?
a) By touch
b) Insect bite
c) Food or water contaminated with cysts
d) Droplet Infection
Answer: c
Clarification: Pathogen which causes Amoebiasis is Entamoeba histolytica. Certain carriers and vectors serve to transmit the parasite from faeces of the infected person to food and food products, thereby contaminating them. So the intake of contaminated food and water are the main source of infection.
4. Which of the following act as mechanical carriers to transmit Entamoeba histolytica?
a) Housefly
b) Caterpillar
c) Birds
d) Butterfly
Answer: a
Clarification: Houseflies act as mechanical carriers to transmit Entamoeba histolytica. Cysts of Entamoeba histolytica present in the stool of infected person are the source of infection.
5. Which of the following species of Plasmodium don’t cause Malaria?
a) Plasmodium piper
b) Plasmodium vivax
c) Plasmodium falciparum
d) Plasmodium malariae
Answer: a
Clarification: There are five species of Plasmodium which cause Malaria. These are Plasmodium vivax, Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale and Plasmodium knowlesi.
6. Out of 5 species of Plasmodium, which one is the most virulent?
a) Plasmodium vivax
b) Plasmodium falciparum
c) Plasmodium malariae
d) Plasmodium knowlesi
Answer: b
Clarification: Plasmodium falciparum is the deadliest species of Plasmodium that cause malaria in humans. It is responsible for causing roughly 50 % of all malaria cases.
7. Where do the sexual stages of Plasmodium develop in its life cycle?
a) Gut of mosquito
b) Brain of human
c) Red Blood Corpuscles of human
d) Liver of human
Answer: c
Clarification: The sexual stages or the gametocytes of Plasmodium develops in Red Blood Corpuscles of the human. The female gametocytes or megagametocytes are round with food-laden cytoplasm and a small excentric nucleus. Male gametocytes or Microgametocytes have a clear cytoplasm and a large central nucleus. Both contain a large amount of haemozoin.
8. In which form Plasmodium enters the human body?
a) Phanerozoites
b) Cryptozoites
c) Gametocytes
d) Sporozoites
Answer: d
Clarification: Plasmodium enters the human body as sporozoites through the bite of infected female Anopheles. Malarial Parasite requires two hosts to complete its life cycle-Human and Anopheles mosquito which also acts as a vector or a transmitting agent.
9. Shuffner’s dots are related to _________
a) Entamoeba histolytica
b) Mosquito
c) Red Blood Corpuscles
d) Liver
Answer: c
Clarification: Shuffner’s dots are related to the Red Blood Corpuscles of humans. They are present in the cytoplasm of RBCs. Presence of these granules indicates that RBCs are infected with Plasmodium.
10. When can malarial parasite be obtained in RBCs of a patient?
a) When there is a sudden increase in pulse rate
b) When the temperature rises with rigour
c) When the temperature of a patient suddenly drops
d) When a patient experiences shortness of breath