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
-
P. vivax
-
P. falciparum
-
P. ovale
-
P. malariae
B
Correct answer
Explanation
P. falciparum is the deadliest malaria-causing agent. It is responsible for 85% of malaria cases.
-
high possibility of drug resistance
-
formation of merozoites
-
its tendency to infect large proportion of the RBC
-
the fact that mosquitoes are the most favourable definitive host
C
Correct answer
Explanation
P. falciparum has the tendency to infect large proportion of RBC. Patients infected with P. falciparum species will exhibit ten times the number of parasites per cubic millimetre of blood than the patients infected with the other three malaria species.
-
Merozoites
-
Sporozoites
-
Gametocytes
-
Hypnozoites
B
Correct answer
Explanation
The humans acquire malarial parasite in the form of sporozoites which are haploid cells.
-
thalassemia
-
magaloblastic anemia
-
sickle cell anemia
-
pernicious anemia
C
Correct answer
Explanation
The patients of sickle cell anemia are naturally resistant to malaria. It is probably by microRNAs entering the parasite and tampering with its genome according to the latest research OR it may be due to smaller numbers of P. falciparum being able to infect sickled cells due to their shapes and increased rates of phagocytosis of infected sickled cells.
-
parasites are released outside by hepatocytes in the plasma
-
the parasite is living inside RBCs
-
parasites are in merozoite form inside the liver
-
sporozoites are outside liver
B
Correct answer
Explanation
Most of the malarial drugs like chloroquine, primaquine, etc. destroy the malarial parasites while they are living inside red blood cells.
-
salivary gland of the mosquito
-
blood cells of the humans
-
gut of the mosquito
-
liver of the humans
C
Correct answer
Explanation
Mating of the gametocytes takes place in the gut of mosquito. After mating, the resultant embryo embed themselves in the mosquito’s gut, where they mature after 9 to 14 days into oocysts.
-
Merozoite
-
Gametocyte
-
Trophozoite
-
Ookinete
B
Correct answer
Explanation
The malarial parasite enters the gut of mosquito in the form of gametocyte. These will mate only when they enter the gut of another mosquito that bites the infected person.
-
oocyst
-
ookinete
-
sporozoite
-
schizont
B
Correct answer
Explanation
The embryonic form of malarial parasite is known as ookinetes. These embed themselves in the mosquito’s gut, where they mature after 9 to 14 days into oocysts.
-
P. ovale
-
P. knowlesi
-
P. malariae
-
P. vivax
C
Correct answer
Explanation
P. malariae has the longest erythrocytic cycle. It is of 72 hours.
-
chloroquine
-
mefloquine
-
sulfadoxine–pyrimethamine
-
coartem
A
Correct answer
Explanation
The first resistant malarial parasite was resistant to chloroquine. It was reported in Thailand in 1957.
-
Trophozoite
-
Merozoite
-
Hypnozoite
-
Sporozoite
C
Correct answer
Explanation
Hypnozoite is the dormant state of malarial parasite, latent hypnozoites may rest undetected in the liver for up to 30 years.
-
Spleen
-
Blood cells
-
Liver
-
Pancreas
C
Correct answer
Explanation
Liver is the first organ invaded by a malarial parasite. Malarial parasites enter human body as sporozoites and are carried to the liver where they mature into forms known as schizonts. Over the next one to two weeks, each schizont multiplies into thousands of other forms known as merozoites. The merozoites break out of the liver and re-enter the bloodstream.
-
liver
-
kidney
-
brain
-
All of these
D
Correct answer
Explanation
P. falciparum causes severe malaria and affects brain, liver and kidney.
-
P. malariae
-
P. falciparum
-
P. ovale
-
P. vivax
B
Correct answer
Explanation
Black water fever (BWF) is a severe clinical syndrome, characterised by intravascular hemolysis, hemoglobinuria (with passage of black urine), and acute renal failure caused by a variety of factors in patients with P. falciparum infestation.
-
Trypanosoma gambiense
-
Staphylococcus
-
Leishmania donovani
-
Ascaris
-
None of these
C
Correct answer
Explanation
Yes, it causes kala azar or black fever.