GENERAL HISTOLOGY

OESOPHAGUS STOMACH

ECHINODERMS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Molluscs in class Bivalvia
A
have two shells
B
lack a “head”
C
Do not have a radula
D
All of the above
Explanation: 

Detailed explanation-1: -Clams, mussels, oysters, and scallops are members to the class Bivalvia (or Pelecypodia). Bivalves have two shells, connected by a flexible ligament, which encase and shield the soft vulnerable parts of the creature.

Detailed explanation-2: -Oysters, clams, mussels, scallops, cockles, coquinas, and many more are all part of the class Bivalvia. Most soft-bodied, aquatic animals with two shells fall into this group. Bivalves are found in all types of water.

Detailed explanation-3: -The class includes the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders.

Detailed explanation-4: -Bivalves do not have a radula (Fig. 3.63). The food suspended in mucus moves through the digestive organs, which break it down and absorb it. Bivalves such as clams, oysters, and scallops are valuable as food.

Detailed explanation-5: -The three major groups of mollusks are gastropods, bivalves, and cephalopods (SEF ul o pods). The largest group is the gastropods. These are mollusks like snails and slugs that have just one shell or no shell at all.

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