Clam Dissection Flashcards

Questions and Answers

What are the three taxonomic classifications for clams?

Animalia, Mollusca, Bivalvia (correct)

Animalia, Arthropoda, Bivalvia

Animalia, Mollusca, Insecta

Plantae, Mollusca, Bivalvia

Why are clams called bivalves?

Bi means 2, valve means shell.

What are siphons and what is their purpose?

They are filters through which water is sucked; this allows only food particles to enter the clam.

Adults are usually sessile, but the larva or ______________ is free swimming.

Trocophore Signup and view all the answers

Body organs make up the ___________ mass.

Visceral Signup and view all the answers

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

It is the Umbo, located as the coiled up hump-like structure with tight rings. 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.

Excurrent and Incurrent. 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 inside lining of the shell.

Called the nacre, 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?

They help align the valves properly while closing to form a tight seal. Signup and view all the answers

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

It is located midway on the anterior surface of the shell and secretes the shell. Signup and view all the answers

Describe the clam's foot.

It is wedge or axe-shaped to help it dig. Signup and view all the answers

What is the mantle cavity?

The large space found between the two lobes of the mantle where water flows. Signup and view all the answers

How do clams breathe?

Clams use two 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?

Cilia on the gills. Signup and view all the answers

Where are the palps found and what is their function?

Located at the anterior end of each set of gills, they direct trapped food toward the mouth. Signup and view all the answers

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

Plankton > Incurrent siphon > Mucous on gills > Cilia toward labial palps > Labial palps > Mouth > Stomach > Intestine > Anus > Excurrent Siphon. Signup and view all the answers

Where is the clam's heart located?

In the pericardial area, on the dorsal surface that the intestine passes through. Signup and view all the answers

Why are clams referred to as 'filter feeders'?

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

What are the parts of the clam's nervous system?

Clams don't have a formal nervous system but have ganglia and nerve cords. Signup and view all the answers

What are some miscellaneous characteristics of clams?

Open circulatory system, indirect development, marine=external fertilization, freshwater=internal fertilization, invertebrates, protostomes, no cephalization. Signup and view all the answers

Study Notes

Clam Anatomy and Function

Clams belong to Kingdom Animalia, Phylum Mollusca, and Class Bivalvia/Pelecypoda.
Called bivalves due to having two shells (valves).
Siphons filter water to allow only food particles to enter the clam.
Larvae known as trocophore are free-swimming; adult clams are usually sessile.

Shell Structure

The oldest part of a clam's shell is the umbo, characterized by its coiled, hump-like structure with tight rings.
Rings on the shell indicate age; more rings represent older clams.
Hinge ligaments hold the two shells together.
Adductor muscles are responsible for opening and closing the clam.

Interior Features

The inside lining of the shell is called nacre, soft and smooth, providing protection.
Dorsal edge of the valves has tooth-like projections that ensure the proper alignment of shells for a tight seal.

Mantle and Foot

The mantle is located midway on the anterior surface and secretes the shell while also serving a respiratory function.
The clam's foot is wedge or axe-shaped, aiding in digging.

Mantle Cavity and Breathing

The mantle cavity is the large space between mantle lobes, where water flows over food and visceral mass.
Clams breathe using two pairs of feathery gills, where oxygen diffuses for respiration.
Cilia on the gills help direct water over them.

Digestive and Nervous System

Labial palps, located at the anterior end of gills, direct trapped food towards the mouth.
Food movement follows this pathway: plankton → incurrent siphon → mucous on gills → cilia to labial palps → mouth → stomach → intestine → anus → excurrent siphon.
Clams have a primitive nervous system with ganglia and nerve cords but lack a formal structure.

Reproduction and Circulatory System

Clams are filter feeders, trapping plankton from water for digestion.
They possess an open circulatory system, with distinct reproductive methods: marine clams undergo external fertilization, while freshwater clams use internal fertilization.
Clams are invertebrates, protostomes, and exhibit no cephalization.

Studying That Suits You

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

Description

Test your knowledge on clams with these flashcards that cover key concepts such as their classification, anatomy, and functionality. Understand the importance of bivalves and the role of siphons in their feeding mechanisms. Perfect for biology students and enthusiasts!