Answer: Depending on the nature of the signaling molecule, it may either bind to and activate a receptor protein embedded in the plasma membrane, or it may move across the plasma membrane and bind to a receptor protein in the cytoplasm.
Explanation: I found this answer on quizlet
Answer:
The correct answer is option a. "scales".
Explanation:
The missing information of this question is the following:
"Terry catches a ray-finned fish from the ocean and notices that attached to its flank is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a s*cker, and two small eyes. Terry concludes it is a hagfish."
Gymnophiona is a group of amphibians characterized by having dermal scales as integumentary element. These amphibians are tetrapods and their scales are comprised of several layers of unmineralized collagenous fibers. The skeleton of the hagfish is made entirely of cartilage, therefore it is very likely that the tooth-like objects of hagfish's are made of cartilage, just like the scales of the tetrapod.
Protection for the head is needed in cases of direct collision sports like hockey and football. Collisions with another player or the turf may result in a concussion, thus all the helmets must possess NOCSAE certifications.
The helmet should fit comfortably around all the segments of the player's head, there should be no gaps between the head and pads. It should cover the base of the skull, the pads positioned at the back of the neck should be comfortable, and at the same time should not be uncomfortable.
The helmet should not come down over the eyes, the front edge of the helmet should be 3/4 inch or of two finger widths above the eyebrows.
Natural selection it has to be 20 characters so disreguard the rest
