It Is Believed That in Flatworms,water Enters the Protonephridia (Flame

question 21

Short Answer

It is believed that in flatworms,water enters the protonephridia (flame cells)from the surrounding tissues by negative pressure from the ___________ beating.

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Definitions:

Neural Tube

Tube formed from the neuroectoderm by the closure of the neural groove; develops into the spinal cord and brain.

Neural Plate

Region of the dorsal surface of the embryo that is transformed into the neural tube and neural crest.

Primitive Streak

An early structure that forms in the developing embryo, crucial for the process of gastrulation and establishing the body plan of the organism.

Notochord

Small rod of tissue lying ventral to the neural tube. A characteristic of all vertebrates, in humans it becomes the nucleus pulposus of the intervertebral disks.