Clam Dissection Questions Flashcards

Questions and Answers

What is the kingdom, phylum, and class for the clam?

Kingdom - Animalia, Phylum - Mollusca, Class - Bivalva

Describe the body of the bivalves.

Shell divided by two halves and connected by a hinge; coelmate with 2 openings.

How do bivalves move?

Use muscular foot to burrow.

Why are they called bivalves?

They have two shells (valves); 'bi' means 2 and 'valve' means shell. Signup and view all the answers

Do bivalves show cephalization? Explain your answer.

No, because they don't have a head. Signup and view all the answers

What are siphons and what are their purpose?

Two openings on the posterior end of the clam. The incurrent siphon carries water into the clam, and the excurrent siphon allows waste water to leave. Signup and view all the answers

Body organs make up the ______ mass and are protected by the _ which secretes the _______.

visceral, mantle, shell Signup and view all the answers

Is circulation open or closed?

Open Signup and view all the answers

Why are clams referred to as 'filter feeders'?

They filter plankton out of the water and trap it to direct it to their digestive tracts. Signup and view all the answers

What is the oldest part of the clam shell?

The umbo Signup and view all the answers

How do clams open and close their shells?

Using anterior and posterior adductor muscles. Signup and view all the answers

How does a clam draw water into its mantle cavity?

Through the incurrent siphon. Signup and view all the answers

What is the purpose of the incurrent siphon's behavior?

To bring in food. Signup and view all the answers

Describe the shape of a clam's foot.

It is hatchet-shaped. Signup and view all the answers

How does the clam use its foot for movement?

As an anchor, to burrow into mud or sand. Signup and view all the answers

Why is the layer called mother of pearl appropriately named?

It creates a pearl from a grain of sand. Signup and view all the answers

What is the oldest part of a clam's shell called and how can it be located?

The umbo; it is located at the hinge where the clam opens. Signup and view all the answers

What do the rings on the clam's shell indicate?

They indicate how old the clam is; the more rings, the older the clam. Signup and view all the answers

Name the clam's siphons.

Incurrent siphon, excurrent siphon. Signup and view all the answers

What holds the two shells together?

Hinge ligaments. Signup and view all the answers

What muscles open and close the clam?

Adductor muscles. Signup and view all the answers

Describe the lining of the shell.

It is soft, smooth, and protects the shell. Signup and view all the answers

What is the function of the tooth-like projections at the dorsal edge of the clam's valves?

Help the valves align properly while closing and ensure a tight seal. Signup and view all the answers

Where is the mantle located in the clam and what is its function?

Midway on the anterior surface of the shell; it secretes the shell and functions as a respiratory organ. Signup and view all the answers

Describe the clam's foot.

It is hatchet-shaped and used for locomotion. Signup and view all the answers

What is the mantle cavity?

The space inside the mantle where water flows and food and visceral mass are located. Signup and view all the answers

How do clams breathe?

Using 2 pairs of feathery gills for respiration as oxygen diffuses into the gills. Signup and view all the answers

What helps direct water over the gills?

Incurrent siphon and excurrent siphon. Signup and view all the answers

Where are the palps found and what is their function?

They are anterior to the gills and guide food into the clam's mouth. Signup and view all the answers

Describe the movement of food through the current siphon in the digestive system of the clam.

It takes in water through the incurrent siphon, moves over gills, into the mouth, through the esophagus into the stomach, then through the intestine and exits the anus via the excurrent siphon. Signup and view all the answers

Where is the clam's heart located?

By the hinge. Signup and view all the answers

Study Notes

Clam Anatomy and Classification

Kingdom: Animalia
Phylum: Mollusca
Class: Bivalva

Body Structure

Bivalves possess two shell halves (valves) connected by a hinge.
Coelomate body plan with two openings for digestive and waste systems.

Movement

Clams use a muscular foot for burrowing and attachment to substrates.

Cephalization

No cephalization present; clams lack a defined head.

Siphons Function

Two siphons (incurrent and excurrent) aid in water flow for feeding and waste removal.
Incurrent siphon brings water in, while excurrent siphon expels water and waste.

Visceral Mass and Shell

Body organs are contained in the visceral mass, protected by the mantle which secretes the shell.

Circulatory System

Clams have an open circulatory system.

Feeding Mechanism

Known as "filter feeders," clams trap plankton from water to direct into their digestive tract.

Shell Anatomy

The umbo is the oldest part of the clam’s shell found at the hinge.
Shell rings indicate age; more rings correspond to older clams.

Shell Mobility

Anterior and posterior adductor muscles allow the clam to open and close its shell.

Incurrent Siphon Purpose

Main function is to draw in water for feeding.

Foot Shape and Function

The foot is hatchet-shaped and used for locomotion by anchoring and burrowing.

Mother of Pearl

The inner layer, known for creating pearls, forms around irritants like grains of sand.

Shell Structure

The lining is soft and smooth, providing protection for the internal organs.

Dorsal Edge Projections

Tooth-like projections on the shell’s edge ensure proper alignment and tight sealing when the shell closes.

Mantle Location and Function

Located midway along the anterior shell surface; secretes the shell and assists in respiration.

Mantle Cavity

The area inside the mantle allowing water flow, housing gills, and containing the visceral mass.

Respiratory System

Clams respire using two pairs of feathery gills for gas exchange, absorbing oxygen from water.

Food Processing Pathway

Food is processed through a sequence: swallowed through siphon, passes over gills, into mouth, esophagus, stomach, intestine, and exits via the anus through the excurrent siphon.

Palps Function

Flap-like structures located anterior to gills guide food into the mouth.

Heart Location

The clam's heart is situated near the hinge, contributing to its circulatory system.

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Description

Test your knowledge on clam dissection with these flashcards. This quiz covers essential information such as taxonomy, body structure, movement, and the defining features of bivalves. Perfect for students studying marine biology or mollusks.