Question

Gill slit behind the head is a functional organ in Adult humans
Embryos of all non-vertebrates
Fish
Adults of all vertebrates​

Answer 1

Explanation:

The presence of the gill slits suggests that a long time ago humans and fish shared a common ancestor. The similarities between embryos suggests that these animals are related and have common ancestors.

Answer 2

Fish is the correct answer.

• Gill slits are the clefts present on the body.
• The gill slits perform an important function of gas exchange.
• They are also present in primitive chordates, where they perform the function of filtering food particles present in water.
• Common examples of organisms carrying gill slits are - fish, shark, some amphibians etc.