Answer:
deuterostomes
Explanation:
During the formation of the gastrula, a group of cells migrates towards the inside. The resultant sac forms the embryonic gut. The embryonic gut has an opening that opens to the outside and is called the blastopore. The blastopore may give rise to mouth or anus. In some organisms, blastopore develops into the anus. These organisms are called deuterostomes. The other organisms in which blastopore develops into the mouth are called protosomes. Echinoderms, hemichordates, and chordates are deuterostomes.
<u>Answer</u>: an all or none response
According to the all-or-none law, it a certain threshol is crossed by a stimulus' strenght, it will cause a response in the nerve cell or muscle fiber. However, the strenght of the response will always be the same and will not vary with different stimulus strengths. The only requirement is for the threshold to be crossed.
Type of energy that can be sensed by the ears is sound energy.
A.
<span>Single-ply membranes are a assorted
and promptly increasing group of sheet materials that are functional to the
roof in a single layer. As equated to built-up membranes, they need less
on-site labor, and they are usually more flexible and therefore less liable to
to cracking and ripping. They are attached to the roof surface by any of
several means.</span>
