Phylum Nematoda Flashcards - Chapter 18
20 Questions
102 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a cuticle?

Non-cellular tough body covering

What are amphids?

Circular concentration sensory organs located at anterior of organism

What is ecdysis?

Shedding periodically 'Molting'

What are phasmids?

<p>Circular concentration sensory organs located at posterior of organism</p> Signup and view all the answers

What is the hypodermis?

<p>Cellular layer lying beneath that secretes the cuticle</p> Signup and view all the answers

What are copulatory spicules?

<p>Needle-like mating structures found only in males</p> Signup and view all the answers

What is hydrostatic pressure?

<p>The pressure excreted by a fluid defined as force per unit area</p> Signup and view all the answers

What is an alimentary canal?

<p>Digestive tract consisting of mouth, pharynx, intestine, rectum, and terminal anus</p> Signup and view all the answers

Describe Phylum Nematoda's classification as Eumetazoan, Triploblastic, etc.

<p>Eumetazoan, Triploblastic, Bilaterally symmetric, Protostome, Ecdysoan, Pseudocoelomate, Schizocoelic</p> Signup and view all the answers

List basic characteristics of Phylum Nematoda.

<p>Pseudocoelom, Triploblastic, Extracellular digestion, Elongated circular bodies, Bilaterally symmetric, Protostomes, Aquatic, Terrestrial, No annuli, No segments, No septum</p> Signup and view all the answers

What is the epidermis's role regarding the cuticle?

<p>Produces the cuticle</p> Signup and view all the answers

What hormone promotes ecdysis?

<p>Ecdysome</p> Signup and view all the answers

Nematodes have a hydrostatic skeleton.

<p>True</p> Signup and view all the answers

How do nematodes accomplish internal fertilization?

<p>Male uses copulatory spicules to hold open female genital pore and muscular contraction shoots sperm into female's genital pore.</p> Signup and view all the answers

Match the nematodes with their characteristics:

<p>Ascaris lumbricoides = Intestinal roundworm Necator americanus = Hookworm Enterobius vermicularis = Pinworm Trichinella spiralis = Trichina worm Wuchereria bancrofti = Elephantiasis</p> Signup and view all the answers

Are nematodes monoecious or dioecious?

<p>Dioecious</p> Signup and view all the answers

Nematodes are described as ______.

<p>Dioecious</p> Signup and view all the answers

What two ways can body-wall muscles in nematodes contract?

<p>Longitudinal, cylindrical</p> Signup and view all the answers

What is the structure of a nematode's digestive system?

<p>Digestive tube with two openings (mouth and anus)</p> Signup and view all the answers

Where is the fluid held in a nematode's hydrostatic skeleton?

<p>Pseudocoelom filled with fluids</p> Signup and view all the answers

Study Notes

Cuticle and Body Structure

  • Cuticle is a non-cellular, tough body covering, secreted by the epidermis.
  • Hypodermis is the cellular layer beneath the cuticle that produces it.
  • Nematodes have a pseudocoelom filled with fluid, acting as a hydrostatic skeleton, surrounded by muscles and bounded by the cuticle.

Sensory Organs

  • Amphids are circular, concentration sensory organs located at the anterior end, responsible for sensing the environment.
  • Phasmids, located at the posterior end, are similar sensory structures also involved in environmental sensing.

Ecdysis and Growth

  • Ecdysis refers to the periodic shedding or molting of the cuticle.
  • Ecdysome hormone promotes ecdysis, essential for growth and development in nematodes.

Muscular and Locomotion Features

  • Nematodes have longitudinal body-wall muscles that contract in a cylindrical shape, enabling a thrashing motion for movement.

Digestive System

  • Nematodes possess an alimentary canal consisting of an open digestive tract with two openings: mouth and anus.
  • The system includes structures such as the mouth, pharynx, intestine, rectum, and terminal anus.

Reproductive Characteristics

  • Nematodes are dioecious, having separate male and female individuals.
  • Fertilization is internal; males utilize copulatory spicules to hold the female's genital pore open and release sperm.

Taxonomy and Classification

  • Phylum Nematoda is eumetazoan, triploblastic, and bilaterally symmetric.
  • Classified into two main classes:
    • Secernentea: Parasitic forms with three esophageal glands and ventral coiled amphids (includes intestinal worms, hookworms, filarial worms, pinworms).
    • Adenophorea: Non-parasitic organisms with well-developed amphids and five esophageal glands (includes Trichinella, whipworm).

Characteristics of Nematodes

  • Basic characteristics include pseudocoelom, triploblastic organization, extracellular digestion, elongated and cylindrical bodies, and lack of annuli, segments, and septum.

Life Cycle and Effects on Humans

  • Ascaris lumbricoides: Found in intestines, feeds on intestinal fluids, causes weight loss, abdominal pain, and fatigue.
  • Necator americanus: Hookworm feeding on blood and mucus, produces fatigue and anemia.
  • Enterobius vermicularis: Pinworm residing in intestines causes itching and discomfort.
  • Trichinella spiralis: Trichina worm found in intestinal tissues, leads to symptoms of muscle pain.
  • Wuchereria bancrofti: Causes elephantiasis due to adult worms in lymphatics.

Key Terms Summary

  • Hydrostatic pressure: The force exerted by fluids, crucial for maintaining body shape in nematodes.
  • Copulatory spicules: Male nematode structures aiding in reproductive function.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

Test your knowledge of Phylum Nematoda with these flashcards from Chapter 18. Each term, from amphids to cuticle, is defined to enhance your understanding of roundworms. Perfect for quick review and memorization.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser