The definition of vestigial organs are rudimentary structures in humans
that correspond to a functional structure or organ in an ancestor.
Basically the answer is redundant organs present in an organism, which
have been functional in the organism's ancestors.
Answer: c) and b) are correct.
The brain is encased in a protective bony or cartilaginous housing in craniates.
The anterior end of the nerve cord is elaborated to form a brain in craniates.
Explanation: The craniates include the chordata with well-defined heads. This includes mammals, reptiles and fishes. So we can discard the other answers. Because most craniates have functional jaws, and the adults do not lose their chordate characteristics. The last one does not apply as a specific feature because the tunicate have neural crest but are not recognized as craniata.
Answer:
0 mya, 175mya, 250mya, 400mya
Explanation:
The substance which highest million year ago should be more in-depth in the soil hence 400mpa should occupy the highest depth below the ground.
I believe the correct answer would be B. Semipermeable means that it allows certain substances to pass through, and certain other ones to not pass through. So given all of your options, I would say that B makes the most sense. Hope this helped!
-TTL