NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
APRIL/MAY 2019 EXAMINATION

BIO 411 PARASITOLOGY - 2 UNITS

INSTRUCTION: ANSWER QUESTIONS 1 AND ANY OTHER THREE.

TIME ALLOWED - 2 HOURS.

1. (a) Explain the following terms: (i) Epidemiology (ii) Prevalence

(iii) Intensity  (iv) DALYs  (v) Parasite  (vi) Parasitism (11 marks)

(b). Classify parasites based on (i) Site of predilection and (ii) duration of degree of dependence (6 marks)

(c) Why are hosts important to parasites? (3 marks)

(d) Define the following types of hosts:

(i) Definitive host

(ii) Intermediate host (iii) Paratenic host. (5 marks)

2. (a) What are (i) Monogenetic and (ii) Digenetic trematodes (6 marks)

(b) Discuss the life cycle of a human Schistosoma species (9 marks)

3. Write short notes on any four of the following:

1. Acanthocephala
2. Nematoda
3. Cestoda
4. Trematoda
5. Protozoa   (15 marks)

4. (a)  Make a labelled drawing of the structure of a typical  Acanthocephalan (6 marks)     

(b)       By means of an annotated diagram only, describe the life cycle of  Polymorphus sp (an acanthocephalan parasite of birds). (9 marks)

        5.      (a)     Name the causative agent and the insect vector of each of the following  diseases

(i) River blindness

(ii) Calabar swelling

(iii) Malaria

(iv) Sleeping sickness

(v) Guineaworm disease

(vi) Elephantiasis (6 marks)

                       (b)     List any five aims of epidemiology. (3 marks)

                       (c)     As a student of parasitology, make a list of one possible disease and one vector or intermediate host of interest in the following communities:

                             (i)    A community that cherishes under cooked pork

(ii)  A community that depends on pond water for drinking and washing, and

(iii) A community in which irrigation and rice farming is the mainstay.     (6 marks)