This is very true but I don't see the question
Answer: ok
Explanation:
I know how to use the food web to determine......
Answer:
The correct answer is option B, that is, an endoskeleton evolved to enclose the dorsal nerve cord, which develops from the notochord.
Explanation:
It has been discovered that the ancestors of the modern-day fish were vertebrate chordates. The vertebrate chordates are considered to have evolved from the invertebrate chordates that are identical to the present day tunicates. It has been found that in vertebrates the endoskeleton has evolved to encompass the dorsal nerve cord that has been developed from the notochord (a characteristic of invertebrates).
The difference between them is that they are active in fighting infection.
Plasma cells are active in defense during the first exposure to invaders like viruses or bacteria producing antibodies. Memory cells last longer and make a copy of the invaders. This allows an extremely rapid defense later in case of a second exposure.