PG TRB ZOOLOGY | Unit I - ANIMAL DIVERSITY AND PHYLOGENY | Structure, life history and disease of helminth parasites – Ascaris lumbricoides.

PG TRB ZOOLOGY ONLINE TEST / QUIZ AS PER LATEST SYLLABUS | Unit I - ANIMAL DIVERSITY AND PHYLOGENY | Structure, life history and disease of helminth parasites – Ascaris lumbricoides.

1. The unique feature of the digestive system in Ascaris lumbricoides is:

• A. It consists of a complete alimentary canal with glands.
• B. It is a blind sac with a single opening.
• C. It is a simple, straight tube without associated glands.
• D. It is absent, as the parasite absorbs food directly.

Correct Answer: C. It is a simple, straight tube without associated glands.

2. Which of the following describes the life cycle of Ascaris lumbricoides?

• A. It involves an intermediate host like a snail.
• B. It is monogenetic, involving only a single host.
• C. It is metagenetic, with alternation of generations.
• D. It is a complex cycle involving multiple larval stages in different hosts.

Correct Answer: B. It is monogenetic, involving only a single host.

3. The characteristic symptom known as "Loeffler's syndrome" in ascariasis is caused by:

• A. Adult worms in the intestine.
• B. Larval migration through the lungs.
• C. The host's immune response to eggs.
• D. Mechanical blockage of the bile duct.

Correct Answer: B. Larval migration through the lungs.

4. The infective stage of Ascaris lumbricoides for humans is the:

• A. Rhabditiform larva.
• B. Embryonated egg.
• C. Filariform larva.
• D. Adult worm.

Correct Answer: B. Embryonated egg.

5. The outer layer of the Ascaris egg, which is secreted by the uterine wall, is called the:

• A. Vitelline membrane.
• B. Mammillated layer.
• C. Albuminous layer.
• D. Chitinous layer.

Correct Answer: B. Mammillated layer.

6. The male Ascaris can be distinguished from the female by the presence of a:

• A. Straight posterior end.
• B. Sucker at the anterior end.
• C. Ventrally curved posterior end with spicules.
• D. Larger body size.

Correct Answer: C. Ventrally curved posterior end with spicules.

7. The larval stage of Ascaris that migrates through the circulatory system to the lungs is known as:

• A. Microfilaria.
• B. Cysticercus.
• C. Rhabditiform larva.
• D. Oncosphere.

Correct Answer: C. Rhabditiform larva.

8. The phenomenon of larval migration of Ascaris from the liver to the lungs is called:

• A. Enterohepatic circulation.
• B. Hepato-pulmonary migration.
• C. Portal-systemic shunt.
• D. Larval pneumonitis.

Correct Answer: B. Hepato-pulmonary migration.

9. The pseudocoel of Ascaris is filled with a fluid called:

• A. Coelomic fluid.
• B. Pseudocoelomic fluid.
• C. Haemocoel.
• D. Lymph.

Correct Answer: B. Pseudocoelomic fluid.

10. A characteristic feature of the body wall of Ascaris is the presence of a thick, non-cellular outer layer called the:

• A. Epidermis.
• B. Hypodermis.
• C. Cuticle.
• D. Tegument.

Correct Answer: C. Cuticle.

11. In the excretory system of Ascaris, the two longitudinal canals are joined by a transverse canal to form an 'H' shape. This system is a modification of:

• A. Flame cells.
• B. Protonephridia.
• C. Metanephridia.
• D. Solenocytes.

Correct Answer: B. Protonephridia.

12. The copulatory spicules are found in:

• A. Male Ascaris.
• B. Female Ascaris.
• C. Both male and female Ascaris.
• D. Larval stages only.

Correct Answer: A. Male Ascaris.

13. The embryonated egg of Ascaris, after ingestion by a human, hatches in the:

• A. Stomach.
• B. Small intestine.
• C. Large intestine.
• D. Liver.

Correct Answer: B. Small intestine.

14. The pharyngeal glands of Ascaris secrete an enzyme that helps in:

• A. Digestion of carbohydrates.
• B. Digestion of proteins.
• C. Breaking down host tissue.
• D. Digestion of lipids.

Correct Answer: C. Breaking down host tissue.

15. The condition of having a pseudocoelom is a characteristic of which phylum, to which Ascaris belongs?

• A. Annelida.
• B. Platyhelminthes.
• C. Nematoda.
• D. Arthropoda.

Correct Answer: C. Nematoda.

16. The larval stage of Ascaris that develops within the egg is called:

• A. Filariform larva.
• B. Rhabditiform larva.
• C. Microfilaria.
• D. Gastrula.

Correct Answer: B. Rhabditiform larva.

17. Which organ is NOT part of the migratory pathway of Ascaris larvae in the human body?

• A. Liver.
• B. Brain.
• C. Lungs.
• D. Heart.

Correct Answer: B. Brain.

18. The number of lips present at the anterior end of an adult Ascaris is:

• A. One.
• B. Two.
• C. Three.
• D. Four.

Correct Answer: C. Three.

19. The cuticle of Ascaris is composed primarily of a protein similar to:

• A. Collagen.
• B. Keratin.
• C. Chitin.
• D. Elastin.

Correct Answer: A. Collagen.

20. Which of the following is an effect of chronic ascariasis on the human host?

• A. Increased appetite.
• B. Malnutrition and stunted growth.
• C. Increased weight gain.
• D. Hyperactivity.

Correct Answer: B. Malnutrition and stunted growth.

21. Fertilized Ascaris eggs are characterized by their:

• A. Symmetrical shape and thin shell.
• B. Asymmetrical shape and lack of an outer layer.
• C. Rounded shape and thick, mammillated outer layer.
• D. Ellipsoidal shape and thick inner shell only.

Correct Answer: C. Rounded shape and thick, mammillated outer layer.

22. The term "pseudocoelomate" refers to an animal that has:

• A. A true coelom lined by mesoderm.
• B. No body cavity.
• C. A body cavity not fully lined by mesoderm.
• D. A body cavity formed from the archenteron.

Correct Answer: C. A body cavity not fully lined by mesoderm.

23. In the life cycle of Ascaris, the second molt of the larva occurs in the:

• A. Intestine.
• B. Lungs.
• C. Trachea.
• D. Liver.

Correct Answer: B. Lungs.

24. The presence of male and female individuals in Ascaris indicates that the species is:

• A. Monoecious.
• B. Hermaphroditic.
• C. Dioecious.
• D. Parthenogenetic.

Correct Answer: C. Dioecious.

25. The main function of the excretory system in Ascaris is:

• A. Osmoregulation.
• B. Excretion of nitrogenous waste.
• C. Both osmoregulation and excretion.
• D. Digestion.

Correct Answer: A. Osmoregulation.

26. The pharynx of Ascaris is a muscular, triradiate structure used for:

• A. Grinding food.
• B. Pumping food into the intestine.
• C. Attachment to the host wall.
• D. Respiration.

Correct Answer: B. Pumping food into the intestine.

27. The large size of the uterus in a female Ascaris is an adaptation for:

• A. Storing large quantities of sperm.
• B. Producing a large number of eggs.
• C. Providing a stable environment for larval development.
• D. Secreting the mammillated layer.

Correct Answer: B. Producing a large number of eggs.

28. The disease caused by Ascaris lumbricoides is medically known as:

• A. Taeniasis.
• B. Filariasis.
• C. Ascariasis.
• D. Enterobiasis.

Correct Answer: C. Ascariasis.

29. What is the typical habitat of an adult Ascaris lumbricoides?

• A. Human liver.
• B. Human lungs.
• C. Human small intestine.
• D. Human colon.

Correct Answer: C. Human small intestine.

30. The process by which Ascaris eggs become infective in the soil is called:

• A. Encystment.
• B. Embryonation.
• C. Sporulation.
• D. Pupation.

Correct Answer: B. Embryonation.

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