Examkin

Question

Difficulty: MediumExcretion and Excretory Organs

In a comparative anatomical study of invertebrates, four different specimens were analyzed to identify their primary excretory organs: a crayfish (crustacean), a planarian (flatworm), a housefly (insect), and an earthworm (annelid). Which of the following correctly pairs each organism with its characteristic excretory structure?

  1. Crayfish: Green gland; Planarian: Flame cell; Housefly: Malpighian tubule; Earthworm: NephridiumAnswer
  2. B
    Crayfish: Malpighian tubule; Planarian: Nephridium; Housefly: Green gland; Earthworm: Flame cell
  3. C
    Crayfish: Flame cell; Planarian: Green gland; Housefly: Nephridium; Earthworm: Malpighian tubule
  4. D
    Crayfish: Nephridium; Planarian: Malpighian tubule; Housefly: Flame cell; Earthworm: Green gland

Answer

Crayfish possess green glands (antennal glands), planarians use specialized flame cells (protonephridia), houseflies rely on Malpighian tubules, and earthworms excrete metabolic waste using nephridia (metanephridia).
Different invertebrate groups possess specialized excretory structures adapted to their body plans and habitats. Crustaceans such as the crayfish excrete via green glands (antennal glands) located at the base of the antennae. Platyhelminthes (flatworms like planarians) utilize protonephridia equipped with cilia-propelled flame cells. Insects like the housefly use Malpighian tubules extending into the hemolymph to discharge waste into the alimentary canal. Annelids such as earthworms possess segmentally arranged nephridia.

Step-by-Step Solution

1
Identify the taxonomic class and corresponding excretory structure for each organism.
Crayfish (Crustacea) -> Green gland; Planarian (Platyhelminthes) -> Flame cell; Housefly (Insecta/Arthropoda) -> Malpighian tubule; Earthworm (Annelida) -> Nephridium.
Different invertebrate phyla have evolved distinct physiological organs to eliminate nitrogenous waste and maintain osmoregulation.
2
Evaluate the option choices to find the accurate set of pairings.
The pairing matching Crayfish to Green gland, Planarian to Flame cell, Housefly to Malpighian tubule, and Earthworm to Nephridium is correct.
All four organism-to-organ mappings in this combination align precisely with invertebrate excretory system anatomy.

Key Concept

Invertebrate Excretory Organs and Phylum Mapping
Rate this question

Topics

Excretion and Excretory Organs

More questions from this topic