General Zoology - Nematodes Overview

Which of the following statements is true regarding Ascaris lumbricoides?

The cuticle of Ascaris lumbricoides is composed of keratin.

What is the infective stage of Ascaris lumbricoides?

The mode of transmission for Ascaris lumbricoides is through contaminated ______.

Match the following characteristics with their corresponding terms related to Ascaris lumbricoides:

What is the main characteristic that distinguishes nematodes from other worm groups?

All nematodes are parasitic.

What type of body organization do nematodes exhibit?

Nematodes are also known as ________ due to their cylindrical shape.

Match the following nematode characteristics with their descriptions:

Which of the following best describes the respiratory process in parasitic nematodes?

Nematodes possess well-developed sense organs.

What type of fertilization do nematodes undergo?

General Zoology - Phylum Nemathelminthes (Nematodes)

Nematodes are thread-like, unsegmented, triploblastic worms.
They are pseudocoelomate, meaning their body cavity is not lined with mesoderm.
Many are parasitic, while others are free-living.
They have a cylindrical body that tapers at both ends.
They have a complete digestive system with a mouth and anus.
Their body is covered by a tough, resistant cuticle.
They are often called roundworms.
Their nervous system is relatively simple, with sensory organs like amphids and phasmids.
They are unisexual with separate sexes, though males are usually smaller than females.
Some exhibit sexual dimorphism.

Distinguishing Features: Free-living vs. Parasitic Nematodes

Free-living nematodes typically have simpler excretory systems (or none at all) and are often found in soil or water.
Parasitic nematodes have more complex excretory systems and often specialized structures for penetrating host tissues.
Free-living nematodes are typically simpler in structure than parasitic nematodes, which often have adaptations for surviving within a host.

Mode of Transmission of Parasitic Nematodes

Information on specific nematodes and their modes of transmission is included in the provided examples.
Some parasitic nematodes may be transmitted via contaminated food or water or directly transmitted through contact.
The specific transmission methods vary considerably across species.

Examples of Parasitic Nematodes and Diseases

Ascaris lumbricoides: Roundworm causing ascariasis.
Wuchereria bancrofti: Filarial worm causing elephantiasis.
Enterobius vermicularis: Pin/threadworm causing churna.
Loa loa: Eyeworm causing conjunctivitis.
Ancylostoma duodenale: Hookworm causing ancylostomiasis.
Trichuris trichiura: Whipworm.
The provided document includes images of these specific nematodes.

Explore the fascinating world of nematodes, or roundworms, in this quiz on Phylum Nemathelminthes. Learn about their unique characteristics, life cycles, and differences between free-living and parasitic species. Test your knowledge on their anatomy, biology, and ecological roles.