Squid: mollusc Crab: Arthropods Crayfish: Arthropods Polychaete: Annelids Homologous organs are the one that develop from common ancestor and have diverged to perform different functions according to the habitat and habit of the organisms. Lateral appendages present in Crab (arthropod), crayfish (arthropod) and polychaete (annelid) exhibit homology. The lateral appendages (parapodia) in polychaete worms extend from the body segments and serve in locomotion. However, soft body plan does not fix them firmly. On the other hand, arthropods have hard bodied skeleton. Crab and crayfish takes advantage of hard bodied skeleton and their lateral appendages are fixed firmly in the skeleton to provide maximum leverage. Development of parapodia in polychetes allowed them to thrive out of burrow in the muddy oceanic sediments. Solution Squid: mollusc Crab: Arthropods Crayfish: Arthropods Polychaete: Annelids Homologous organs are the one that develop from common ancestor and have diverged to perform different functions according to the habitat and habit of the organisms. Lateral appendages present in Crab (arthropod), crayfish (arthropod) and polychaete (annelid) exhibit homology. The lateral appendages (parapodia) in polychaete worms extend from the body segments and serve in locomotion. However, soft body plan does not fix them firmly. On the other hand, arthropods have hard bodied skeleton. Crab and crayfish takes advantage of hard bodied skeleton and their lateral appendages are fixed firmly in the skeleton to provide maximum leverage. Development of parapodia in polychetes allowed them to thrive out of burrow in the muddy oceanic sediments..

1. Squid: mollusc
Crab: Arthropods
Crayfish: Arthropods
Polychaete: Annelids
Homologous organs are the one that develop from common ancestor and have diverged to
perform different functions according to the habitat and habit of the organisms. Lateral
appendages present in Crab (arthropod), crayfish (arthropod) and polychaete (annelid) exhibit
homology. The lateral appendages (parapodia) in polychaete worms extend from the body
segments and serve in locomotion. However, soft body plan does not fix them firmly. On the
other hand, arthropods have hard bodied skeleton. Crab and crayfish takes advantage of hard
bodied skeleton and their lateral appendages are fixed firmly in the skeleton to provide maximum
leverage. Development of parapodia in polychetes allowed them to thrive out of burrow in the
muddy oceanic sediments.
Solution
Squid: mollusc
Crab: Arthropods
Crayfish: Arthropods
Polychaete: Annelids
Homologous organs are the one that develop from common ancestor and have diverged to
perform different functions according to the habitat and habit of the organisms. Lateral
appendages present in Crab (arthropod), crayfish (arthropod) and polychaete (annelid) exhibit
homology. The lateral appendages (parapodia) in polychaete worms extend from the body
segments and serve in locomotion. However, soft body plan does not fix them firmly. On the
other hand, arthropods have hard bodied skeleton. Crab and crayfish takes advantage of hard
bodied skeleton and their lateral appendages are fixed firmly in the skeleton to provide maximum
leverage. Development of parapodia in polychetes allowed them to thrive out of burrow in the
muddy oceanic sediments.