Question

Общим признаком для гидры и медузы является 1) двусторонняя симметрия 2) лучевая симметрия 3) наличие кровеносной системы 4) трёхслойное строение тела

Answer 1

Общим признаком для гидры и медузы является:

2) лучевая симметрия
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Answer 2

Common Characteristics of Hydra and Jellyfish

Both hydra and jellyfish share the following common characteristics:

1) Radial Symmetry - Both hydra and jellyfish exhibit radial symmetry, which means their body parts are arranged around a central axis. This allows them to be symmetrical in any direction from the center point. - "Hydras and jellyfish are both radially symmetrical, meaning that their body parts are arranged around a central axis" .

2) Three-Layered Body Structure - Both hydra and jellyfish have a three-layered body structure, which includes an outer layer (epidermis), a middle layer (mesoglea), and an inner layer (gastrodermis). - "Both hydra and jellyfish have a simple, three-layered body structure" .

Therefore, the common characteristic for both hydra and jellyfish is lack of bilateral symmetry and presence of radial symmetry.