WAEC - Biology (2000 - No. 3)
The hydra has two body layers of cells called
ectodermis and enteron
ectoderm and endoderm
endodermis and dermis
epidermis and dermis
説明
The two body layers of a hydra are the endoderm and ectoderm
- Endoderm: The inner layer of Hydra's body wall
- Ectoderm: The outer layer of Hydra's body wall