MEC Entrance Preparation: Zoology
Topics: Plasmodium, Earthworm, Frog
Topic: Plasmodium (Malaria)
1. The infective stage of Plasmodium for human beings is:
Answer: C (Sporozoite)
Infective stage for man is Sporozoite (inoculated by mosquito); Infective stage for mosquito is Gametocyte.
Infective stage for man is Sporozoite (inoculated by mosquito); Infective stage for mosquito is Gametocyte.
2. Which stage of the life cycle of Plasmodium is motile?
Answer: B (Ookinete)
Ookinete is the motile zygote formed in the mosquito's stomach. It penetrates the stomach wall.
Ookinete is the motile zygote formed in the mosquito's stomach. It penetrates the stomach wall.
3. Schuffner’s dots are observed in RBCs infected by:
Answer: C (P. vivax)
Schuffner's dots = P. vivax & P. ovale. Maurer's clefts = P. falciparum. Ziemann's dots = P. malariae.
Schuffner's dots = P. vivax & P. ovale. Maurer's clefts = P. falciparum. Ziemann's dots = P. malariae.
4. Cerebral malaria is a complication caused by:
Answer: B (P. falciparum)
Also known as Malignant Tertian Malaria. It causes cytoadherence of RBCs in brain capillaries.
Also known as Malignant Tertian Malaria. It causes cytoadherence of RBCs in brain capillaries.
5. The sexual cycle of Plasmodium is completed in:
Answer: D (Stomach of Mosquito)
Fertilization (syngamy) occurs in the stomach of the female Anopheles mosquito.
Fertilization (syngamy) occurs in the stomach of the female Anopheles mosquito.
6. Relapse in malaria is due to the persistence of:
Answer: B (Hypnozoites in liver)
Seen in P. vivax and P. ovale. These are dormant hepatic forms causing relapse.
Seen in P. vivax and P. ovale. These are dormant hepatic forms causing relapse.
7. The duration of the erythrocytic cycle in P. malariae is:
Answer: A (72 hours)
Quartan malaria (P. malariae) = 72 hrs. Tertian (P. vivax, P. falciparum, P. ovale) = 48 hrs.
Quartan malaria (P. malariae) = 72 hrs. Tertian (P. vivax, P. falciparum, P. ovale) = 48 hrs.
8. Hemozoin, the malarial pigment, is formed from:
Answer: C (Hematin part of Hb)
The parasite digests Globin (protein) and converts the toxic Heme into insoluble Hemozoin.
The parasite digests Globin (protein) and converts the toxic Heme into insoluble Hemozoin.
9. 'Signet ring stage' is formed by:
Answer: B (Trophozoite)
Early trophozoite develops a central vacuole pushing the nucleus to the periphery, resembling a ring.
Early trophozoite develops a central vacuole pushing the nucleus to the periphery, resembling a ring.
10. Who discovered the oocyst of Plasmodium in the stomach of mosquitoes?
Answer: D (Ronald Ross)
Sir Ronald Ross made this discovery in Secunderabad, India (1897). Laveran discovered the parasite in human blood.
Sir Ronald Ross made this discovery in Secunderabad, India (1897). Laveran discovered the parasite in human blood.
11. Exflagellation is associated with the formation of:
Answer: A (Microgametes)
Male gametocyte undergoes exflagellation in the mosquito stomach to form thread-like microgametes.
Male gametocyte undergoes exflagellation in the mosquito stomach to form thread-like microgametes.
12. Black water fever is caused by:
Answer: B (P. falciparum)
It is due to massive intravascular hemolysis and hemoglobinuria.
It is due to massive intravascular hemolysis and hemoglobinuria.
13. The pre-erythrocytic cycle of Plasmodium occurs in:
Answer: C (Liver)
Pre-erythrocytic schizogony takes place in liver cells immediately after sporozoite entry.
Pre-erythrocytic schizogony takes place in liver cells immediately after sporozoite entry.
14. Which form of Plasmodium is not digested in the mosquito's stomach?
Answer: C (Gametocyte)
All asexual forms are digested; only gametocytes survive to continue the sexual cycle.
All asexual forms are digested; only gametocytes survive to continue the sexual cycle.
15. Accle's crescentic shape is characteristic of gametocytes of:
Answer: B (P. falciparum)
Only P. falciparum has crescent or sausage-shaped gametocytes. Others are spherical.
Only P. falciparum has crescent or sausage-shaped gametocytes. Others are spherical.
Topic: Earthworm (Pheretima posthuma)
16. The clitellum in Pheretima posthuma is found in segments:
Answer: C (14, 15, 16)
Clitellum is a glandular tissue used for cocoon formation, located in segments 14-16.
Clitellum is a glandular tissue used for cocoon formation, located in segments 14-16.
17. Setae are absent in which segments of the earthworm?
Answer: D (First, Last, and Clitellum)
Setae are locomotory organs present in all segments except the peristomium (1st), pygidium (last), and clitellum (14-16).
Setae are locomotory organs present in all segments except the peristomium (1st), pygidium (last), and clitellum (14-16).
18. Chloragogen cells of earthworm are analogous to which vertebrate organ?
Answer: B (Liver)
Chloragogen cells perform deamination, urea synthesis, and glycogen storage, similar to the vertebrate liver.
Chloragogen cells perform deamination, urea synthesis, and glycogen storage, similar to the vertebrate liver.
19. In Pheretima, the heart located in segments 7 and 9 are:
Answer: A (Lateral hearts)
Lateral hearts (7, 9) connect dorsal vessel to ventral vessel. Lateral esophageal hearts (12, 13) connect supra-esophageal/dorsal to ventral.
Lateral hearts (7, 9) connect dorsal vessel to ventral vessel. Lateral esophageal hearts (12, 13) connect supra-esophageal/dorsal to ventral.
20. The typhlosole in earthworm is meant for:
Answer: B (Increasing absorptive surface area)
It is a dorsal fold of the intestine between segments 26 and 35.
It is a dorsal fold of the intestine between segments 26 and 35.
21. Gizzard is found in which segment of Pheretima?
Answer: C (8-9)
The gizzard is a muscular organ used for grinding soil particles.
The gizzard is a muscular organ used for grinding soil particles.
22. Which nephridia in earthworm are exonephric?
Answer: A (Integumentary nephridia)
Integumentary nephridia open to the exterior (Exonephric). Septal and Pharyngeal open into the gut (Enteronephric) to conserve water.
Integumentary nephridia open to the exterior (Exonephric). Septal and Pharyngeal open into the gut (Enteronephric) to conserve water.
23. Blood glands in Pheretima are located in segments:
Answer: D (4, 5, 6)
They produce blood cells and hemoglobin which is dissolved in plasma.
They produce blood cells and hemoglobin which is dissolved in plasma.
24. The male genital pores are located on the ventro-lateral side of segment:
Answer: B (18th)
A pair of male genital pores is present on the 18th segment. Female pore is single on the 14th. Genital papillae on 17 and 19.
A pair of male genital pores is present on the 18th segment. Female pore is single on the 14th. Genital papillae on 17 and 19.
25. Spermathecae are used for storing:
Answer: A (Sperm from another worm)
Spermathecae (4 pairs in 6-9) receive and store sperm during copulation.
Spermathecae (4 pairs in 6-9) receive and store sperm during copulation.
26. The respiratory pigment in earthworm is:
Answer: C (Hemoglobin in Plasma)
Earthworms do not have RBCs. Hemoglobin is dissolved directly in the blood plasma.
Earthworms do not have RBCs. Hemoglobin is dissolved directly in the blood plasma.
27. Enteronephric nephridia are an adaptation for:
Answer: B (Conservation of water)
By discharging waste into the gut, water is reabsorbed by the intestinal wall.
By discharging waste into the gut, water is reabsorbed by the intestinal wall.
28. Which vessel contains valves in the earthworm?
Answer: A (Dorsal blood vessel)
The dorsal vessel is the main collecting vessel and has valves to prevent backflow. Flow is posterior to anterior.
The dorsal vessel is the main collecting vessel and has valves to prevent backflow. Flow is posterior to anterior.
29. Photoreceptors in earthworm are most abundant in:
Answer: C (Prostomium and Peristomium)
They are sensitive to light and are concentrated on the dorsal surface of the anterior end.
They are sensitive to light and are concentrated on the dorsal surface of the anterior end.
30. Earthworms are:
Answer: D (Both A and B)
They are mainly ureotelic (terrestrial), but become ammonotelic when plenty of water is available.
They are mainly ureotelic (terrestrial), but become ammonotelic when plenty of water is available.
Topic: Frog (Rana tigrina)
31. The vertebrae of frogs are mostly:
Answer: B (Procoelous)
Typical frog vertebrae (2nd to 7th) are procoelous (concave in front, convex behind). 8th is Amphicoelous.
Typical frog vertebrae (2nd to 7th) are procoelous (concave in front, convex behind). 8th is Amphicoelous.
32. The heart of a frog is:
Answer: C (3 chambered)
It has 2 auricles and 1 ventricle.
It has 2 auricles and 1 ventricle.
33. The pacemaker of the frog's heart is:
Answer: A (Sinus Venosus)
Sinus Venosus is the triangular chamber on the dorsal side that initiates the heartbeat in frogs.
Sinus Venosus is the triangular chamber on the dorsal side that initiates the heartbeat in frogs.
34. Number of cranial nerves in frog:
Answer: D (10 pairs)
Anamniotes (Fishes, Amphibians) have 10 pairs. Amniotes (Reptiles, Birds, Mammals) have 12 pairs.
Anamniotes (Fishes, Amphibians) have 10 pairs. Amniotes (Reptiles, Birds, Mammals) have 12 pairs.
35. Kidney of an adult frog is:
Answer: B (Mesonephric)
Tadpoles have pronephric kidneys, while adult frogs have mesonephric (opisthonephric) kidneys.
Tadpoles have pronephric kidneys, while adult frogs have mesonephric (opisthonephric) kidneys.
36. Which valve prevents the mixing of oxygenated and deoxygenated blood in the Truncus Arteriosus?
Answer: C (Spiral valve)
The spiral valve in the conus/truncus arteriosus directs blood into appropriate arches (Pulmocutaneous, Systemic, Carotid).
The spiral valve in the conus/truncus arteriosus directs blood into appropriate arches (Pulmocutaneous, Systemic, Carotid).
37. The skull of a frog is:
Answer: A (Dicondylic)
It has two occipital condyles connecting to the atlas vertebra. Mammals are also dicondylic. Reptiles/Birds are monocondylic.
It has two occipital condyles connecting to the atlas vertebra. Mammals are also dicondylic. Reptiles/Birds are monocondylic.
38. Bidder’s canal is found in:
Answer: B (Kidney of male frog)
It conducts sperm from the testis (via vasa efferentia) to the ureter.
It conducts sperm from the testis (via vasa efferentia) to the ureter.
39. RBCs of frogs are:
Answer: C (Oval, Biconvex, Nucleated)
Unlike mammalian RBCs (Circular, Biconcave, Non-nucleated).
Unlike mammalian RBCs (Circular, Biconcave, Non-nucleated).
40. The main nitrogenous waste of an adult frog is:
Answer: A (Urea)
Adult frogs are ureotelic (land adaptation). Tadpoles are ammonotelic (aquatic).
Adult frogs are ureotelic (land adaptation). Tadpoles are ammonotelic (aquatic).
41. Which hormone is responsible for metamorphosis in frogs?
Answer: D (Thyroxine)
Thyroxine (produced by Thyroid) is essential for metamorphosis. Iodine deficiency prevents tadpoles from becoming frogs.
Thyroxine (produced by Thyroid) is essential for metamorphosis. Iodine deficiency prevents tadpoles from becoming frogs.
42. The number of digits in the forelimb and hindlimb of a frog respectively are:
Answer: B (4, 5)
Forelimbs have 4 digits (Thumb/Pollex is absent or vestigial). Hindlimbs have 5 digits with webs.
Forelimbs have 4 digits (Thumb/Pollex is absent or vestigial). Hindlimbs have 5 digits with webs.
43. Corpora bigemina in frogs refers to:
Answer: C (Optic lobes)
Frogs have 2 optic lobes (Corpora bigemina). Mammals have 4 (Corpora quadrigemina).
Frogs have 2 optic lobes (Corpora bigemina). Mammals have 4 (Corpora quadrigemina).
44. The portal system present in frog but absent in mammals is:
Answer: A (Renal portal system)
Frogs have both Renal and Hepatic portal systems. Mammals lack the Renal portal system.
Frogs have both Renal and Hepatic portal systems. Mammals lack the Renal portal system.
45. During hibernation, frog respires through:
Answer: B (Skin only)
Metabolic rate is low during hibernation, so Cutaneous respiration is sufficient.
Metabolic rate is low during hibernation, so Cutaneous respiration is sufficient.
46. The third eyelid in frog is called:
Answer: C (Nictitating membrane)
It protects the eye during swimming.
It protects the eye during swimming.
47. Urostyle in frog is formed by the fusion of:
Answer: D (Caudal vertebrae)
The last 10th vertebra is the long, rod-like Urostyle formed by fusion of tail vertebrae.
The last 10th vertebra is the long, rod-like Urostyle formed by fusion of tail vertebrae.
48. Amplexus is:
Answer: A (Sexual embrace)
False copulation where the male clasps the female to stimulate egg release. Fertilization is external.
False copulation where the male clasps the female to stimulate egg release. Fertilization is external.
49. The liver of frog consists of how many lobes?
Answer: B (3)
Right lobe, Left anterior lobe, and Left posterior lobe.
Right lobe, Left anterior lobe, and Left posterior lobe.
50. The cavity of the brain is known as:
Answer: C (Ventricle)
The hollow cavities inside the brain filled with CSF are called ventricles (Rhinocoel, Paracoel, Diacoel, Metacoel).
The hollow cavities inside the brain filled with CSF are called ventricles (Rhinocoel, Paracoel, Diacoel, Metacoel).
Mixed High-Yield Questions
51. In Earthworm, fertilization occurs in:
Answer: B (Cocoon)
Fertilization is external but takes place inside the cocoon deposited in the soil.
Fertilization is external but takes place inside the cocoon deposited in the soil.
52. Which malarial parasite causes 'Quartan Malaria'?
Answer: C (P. malariae)
Fever repeats every 4th day (72 hours gap). P. vivax causes Benign Tertian.
Fever repeats every 4th day (72 hours gap). P. vivax causes Benign Tertian.
53. Columella auris in frog connects:
Answer: A (Tympanum to Internal Ear)
It is the single ear ossicle (analogous to stapes) in the middle ear of the frog.
It is the single ear ossicle (analogous to stapes) in the middle ear of the frog.
54. Which structure is absent in the male frog?
Answer: D (Uterus)
Male frogs have Vocal sacs, Copulatory pads (on index finger), and Bidder's canal. Only females have ovisacs (uterus).
Male frogs have Vocal sacs, Copulatory pads (on index finger), and Bidder's canal. Only females have ovisacs (uterus).
55. Chromophil cells are found in which part of the earthworm?
Answer: A (Pharyngeal glands)
Chromophil cells produce saliva containing mucin and proteases.
Chromophil cells produce saliva containing mucin and proteases.
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