Phylum Ctenophora Overview

Questions and Answers

What type of organisms are Ctenophores?

Comb jellies (correct)

Fish

Mollusks

Crustaceans

What is the structure that aids in swimming in Ctenophores called?

comb paddle

Which of the following is a characteristic of Ctenophores?

Biradial symmetry (correct)

Triploblastic organization

No nervous system

Presence of nematocysts

What are colloblasts?

Cells found on the tentacles of Ctenophores that discharge an adhesive thread. Signup and view all the answers

What role does the statolith play in Ctenophores?

Enables balance and orientation by stimulating sensory receptors in response to gravity. Signup and view all the answers

What is bioluminescence?

Light produced by organisms as a result of a chemical reaction. Signup and view all the answers

What distinguishes Class Tenaculata within the Ctenophores?

They have tentacles. Signup and view all the answers

What distinguishes Class Nuda within the Ctenophores?

They lack tentacles. Signup and view all the answers

What type of organization do Ctenophores exhibit?

Diploblastic or possibly triploblastic. Signup and view all the answers

Describe cydippid larva.

A free-swimming ctenophore larva with an ovoid or spherical body. Signup and view all the answers

Study Notes

Phylum Ctenophora Overview

Comprises comb jellies, organisms distinct from jellyfish, featuring a simpler life cycle.
Lacks nematocysts (stinging cells); captures prey using sticky cells on two long tentacles.
Locomotion results from the beating of eight rows of cilia known as combs.

Characteristics

Organismic structure is either diploblastic or potentially triploblastic, showing tissue-level organization.
Displays biradial symmetry.
Contains a gelatinous mesoglea situated between epidermal and gastrodermal tissues.
True muscle cells arise within the mesoglea, enabling movement.
Possesses a gastrovascular cavity for digestion.
Nervous system operates as a nerve net, facilitating networked communication.
Features adhesive structures called colloblasts for prey capture.
Movement is facilitated by eight ciliary bands, termed comb rows.

Unique Structures

Comb Paddle: Made up of eight rows of cilia that assist in swimming; each paddle resembles a comb and contains thousands of cilia.
Statolith or Apical Sense Organ: A calcareous particle found within statocysts; responsible for balance and orientation by stimulating sensory receptors in response to gravity.
Colloblast: A specialized cell located on ctenophore tentacles; discharges a sticky adhesive thread to trap prey.

Life Cycle Stages

Cydippid Larva: This larval stage is characterized as free-swimming with an ovoid or spherical shape; represents an early developmental form of ctenophores.

Classes of Ctenophores

Class Tenaculata: Encompasses ctenophores that have tentacles.
Class Nuda: Comprises ctenophores that lack tentacles, showcasing a different structural adaptation.

Bioluminescence

Exhibits bioluminescence, allowing these organisms to produce light through chemical reactions, contributing to their allure in marine environments.

Description

Explore the fascinating world of Ctenophora, commonly known as comb jellies. This quiz covers their unique characteristics, locomotion using cilia, and specialized structures like colloblasts. Test your knowledge on their evolutionary significance and life cycle differences from jellyfish.