Biology 112 Phylum Mollusca Quiz
29 Questions
100 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 the general character trait which distinguished Mollusks?

They are soft-bodied animals that have an internal or external calcium carbonate shell

How diverse is the phylum Mollusca?

They are the second most diverse phylum of animals after the arthropods

Many Mollusca species serve as food for humans.

True

Are most mollusks slow or fast?

<p>Slow, but several species such as squid are modified for rapid locomotion</p> Signup and view all the answers

What is the symmetry of Mollusks?

<p>Bilaterally symmetrical</p> Signup and view all the answers

Are Mollusks diploblastic?

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

Do Mollusks have a true coelom?

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

Mollusks have larger coelom than annelids.

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

Do Mollusks have complete digestive systems?

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

What is a protostome?

<p>An organism in which the first opening that forms during development becomes the mouth.</p> Signup and view all the answers

What is a deuterostome?

<p>Anus develops first; the blastopore becomes the anus.</p> Signup and view all the answers

Is a Mollusk a protostome?

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

What other systems do Mollusks have besides a complex digestive system?

<p>Elaborate respiratory, excretory, and circulatory systems with a heart.</p> Signup and view all the answers

Are Mollusks similar to annelids in their development?

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

How are mollusks different from annelids from a developmental point of view?

<p>Mollusks lack segmentation.</p> Signup and view all the answers

What three body regions do all mollusks have?

<p>Foot, Visceral Mass, Mantle</p> Signup and view all the answers

What is the function of the foot in a mollusk?

<p>The muscular structure used for locomotion in most mollusks.</p> Signup and view all the answers

What is the function of the visceral mass in a mollusk?

<p>Houses all of the internal organ systems.</p> Signup and view all the answers

What is the function of the mantle in a mollusk?

<p>Surrounds the mantle cavity and produces the shell.</p> Signup and view all the answers

What is the function of the mantle cavity?

<p>Water or air circulates continually through the mantle cavity.</p> Signup and view all the answers

The continual flow of water or air throughout the mantle cavity along with the physical and physiological organization of the mantle, mantle cavity, and gills allows the mollusk to __________________________ and __________________________.

<p>Exchange gases and gather food</p> Signup and view all the answers

Many Mollusks feed by using a strap-like organ called a ______________.

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

What process has resulted in lots of morphological variety within this phylum?

<p>The process of evolution by natural selection</p> Signup and view all the answers

How many classes of mollusks are we studying and what are their names?

<p>5: Polyplacophora, Bivalvia, Gastropoda, Cephalopoda, Scaphopoda</p> Signup and view all the answers

How do organisms amongst the different classes of mollusks differ from one another?

<p>The three main body parts are shaped and arranged differently.</p> Signup and view all the answers

What is the basic anatomy of an organism belonging to class Polyplacophora?

<p>The elliptical body is covered by a shell consisting of eight plates.</p> Signup and view all the answers

What kind of organisms are chitons?

<p>Marine organisms; herbivores removing algae off of rocks and other surfaces.</p> Signup and view all the answers

Describe the foot of chitons.

<p>They have a large, broad, flat muscular foot that occupies the greater part of the ventral surface.</p> Signup and view all the answers

Where can chitons be found?

<p>They are usually found on rocks.</p> Signup and view all the answers

Study Notes

General Characteristics of Phylum Mollusca

  • Mollusks are soft-bodied animals, often possessing an internal or external calcium carbonate shell.
  • They rank as the second most diverse phylum in the animal kingdom, following arthropods.

Importance and Locomotion

  • Many mollusk species serve as a food source for humans.
  • Most mollusks are slow, although some, such as squids, are capable of rapid movement.

Body Structure and Symmetry

  • Mollusks exhibit bilateral symmetry.
  • They are triploblastic, developing from three germ layers.

Body Cavity and Digestive System

  • Mollusks have a true coelom, which is a body cavity entirely surrounded by mesoderm.
  • They possess complete digestive systems, allowing for efficient processing of food.

Developmental Classification

  • Mollusks are classified as protostomes, where the mouth develops from the blastopore.
  • In contrast, deuterostomes develop the anus first from the blastopore.

Physiological Systems

  • Mollusks have elaborate respiratory, excretory, and circulatory systems, including a heart.

Morphological Differences from Annelids

  • Unlike annelids, mollusks lack segmentation.
  • Both groups share a trochophore larval phase but differ significantly in development.

Body Regions of Mollusks

  • Mollusks are comprised of three main body regions: foot, visceral mass, and mantle.

Functions of Body Structures

  • The muscular foot serves primarily for locomotion.
  • The visceral mass houses internal organs.
  • The mantle is a tissue layer that surrounds the mantle cavity, responsible for shell production.

Mantle Cavity Functions

  • The mantle cavity allows for continual water or air circulation, facilitating gas exchange and food gathering.
  • Gills are located within the mantle cavity.

Feeding Mechanism

  • Many mollusks utilize a radula, a strap-like organ, for feeding.

Evolutionary Adaptations

  • Diversification in mollusks is attributed to evolution by natural selection, leading to diverse morphologies adapted to various environments.

Classes of Mollusks

  • The five classes studied are:
    • Polyplacophora (chitons)
    • Bivalvia (clams)
    • Gastropoda (snails)
    • Cephalopoda (squids)
    • Scaphopoda (tusk shells)

Class Differences and Anatomy

  • Each class of mollusks exhibits variations in the shapes and arrangements of the three main body parts, leading to functional differences.
  • Polyplacophora features an elliptical body covered by a shell made of eight plates, though some species may lack these.

Chitons

  • Chitons are marine herbivores that graze on algae from rocks.
  • Their broad, flat muscular foot occupies a significant portion of the ventral surface and enhances their ability to cling to surfaces.

Studying That Suits You

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

Quiz Team

Description

Test your knowledge on the characteristics and diversity of Mollusca in this Biology 112 quiz. Explore key traits that make Mollusks unique and their significance in ecosystems and human nutrition. Ideal for students seeking to reinforce their understanding of this fascinating phylum.

More Like This

Mollusca Phylum Characteristics Quiz
16 questions
Biology Chapter 27 and 28 Flashcards
12 questions
Phylum Mollusca Terms Flashcards
20 questions
Use Quizgecko on...
Browser
Browser