In an experiment, Malpighian tubules of a cockroach are removed. Which substance might be absent in its fecal pellets?
1
Undigested matter
2
Urea
3
Uric acid
4
Undigested proteins
Official Solution
Correct Option: (3)
Step 1: Understanding the Role of Malpighian Tubules
- Malpighian tubules in cockroaches function in excretion and produce uric acid as a nitrogenous waste. - Removing them prevents uric acid excretion, so it would be absent in feces. - Other substances like undigested matter and proteins remain unaffected.
02
PYQ 2024
medium
zoologyID: ts-eamce
Excretory organs in adult molluscs are:
1
Malpighian tubules
2
Green glands
3
Coxal glands
4
Pericardial glands
Official Solution
Correct Option: (4)
Step 1: Understanding Molluscan Excretion
- Pericardial glands are the primary excretory organs in molluscs. - Other excretory organs like Malpighian tubules (in insects), Green glands (in crustaceans), and Coxal glands (in arachnids) are incorrect.
03
PYQ 2025
medium
zoologyID: ts-eamce
Selective reabsorption of components in glomerular filtrate is regulated in these parts of nephron
1
Proximal convoluted tubule and distal convoluted tubule
2
Loop of Henle and distal convoluted tubule
3
Distal convoluted tubule and collecting duct
4
Proximal convoluted tubule and Loop of Henle
Official Solution
Correct Option: (3)
Step 1: Understanding Reabsorption Types:
Reabsorption in the nephron can be classified into two types:
Obligatory Reabsorption: Occurs in the Proximal Convoluted Tubule (PCT). It is constant and not hormonally regulated (e.g., bulk reabsorption of water and nutrients).
Facultative (Regulated) Reabsorption: Occurs in the Distal Convoluted Tubule (DCT) and Collecting Duct (CD). This reabsorption is regulated by hormones based on the body's needs.
Step 2: Hormonal Regulation:
Aldosterone: Acts on DCT and CD to increase reabsorption and water follows.
ADH (Vasopressin): Acts on DCT and CD to increase water reabsorption.
Step 3: Conclusion:
Since the question asks for \regulated reabsorption, the answer refers to the DCT and Collecting Duct.
04
PYQ 2025
medium
zoologyID: ts-eamce
Sensillae present on 1st, 2nd and 3rd tarsomeres of leg of cockroach are
1
Olfactory sensillae
2
Thermoreceptor sensillae
3
Gustatory sensillae
4
Chemoreceptor sensillae
Official Solution
Correct Option: (2)
Step 1: Locate the Sensillae:
Cockroaches have various sensory receptors (sensillae) distributed over their body:
Legs (Tarsus): The tarsus is divided into 5 segments (tarsomeres). The soft pads (plantulae) on the underside of the first, second, and third tarsomeres contain specialized thermoreceptor sensillae, allowing the cockroach to detect surface temperature.
Step 2: Final Answer:
The correct option is Thermoreceptor sensillae.
05
PYQ 2025
medium
zoologyID: ts-eamce
Match the following:
1
A III, B V, C I, D IV
2
A IV, B V, C II, D I
3
A II, B I, C V, D III
4
A III, B V, C I, D II
Official Solution
Correct Option: (1)
• Rotifers Protonephridia (A III). • Earthworms Metanephridia (B V). • Terrestrial arthropods Malpighian tubules (C I). • Crustaceans Coxal glands (D IV). • Correct matching is A III, B V, C I, D IV}.
06
PYQ 2025
medium
zoologyID: ts-eamce
Appendages are absent in these segments of head of cockroach
1
1, 3
2
2, 4
3
3, 6
4
5, 6
Official Solution
Correct Option: (1)
The first and third segments of the cockroach head (labrum and clypeus) do not bear appendages. Other head segments bear antennae, mandibles, and maxillae.
07
PYQ 2025
medium
zoologyID: ts-eamce
This part of ommatidium of cockroach is a refractive region
1
Crystalline cone
2
Vitrellar cells
3
Cornea
4
Retinulae
Official Solution
Correct Option: (1)
Concept: The ommatidium is the single unit of an insect's compound eye, split into a light-focusing part and a light-sensing part.
Explanation: The dioptric (light-focusing/refractive) apparatus consists of the cornea (lens) and the **crystalline cone**. The retinulae cells contain the light-sensitive pigment.
08
PYQ 2025
medium
zoologyID: ts-eamce
Observe the list of animals given below: I. Tracheate arthropods II. Land snails III. Hydra IV. Earth worms V. Reptiles VI. Birds VII. Mammals VIII. Bony fishes IX. Amphibians Among the above, ureotelism is found in
1
I, VIII, IX
2
II, III, VI
3
V, VI, IX
4
VII, VIII, IX
Official Solution
Correct Option: (3)
Ureotelic animals excrete urea. Reptiles, birds, and mammals primarily convert ammonia to urea (ureotelism). Other animals may be ammonotelic or uricotelic.
