Builds protein is the correct answer
Answer:
The platypus serves as a 'bridge' animal between nonmammals like birds and reptiles, which maintain their testicles in their body cavity, and placental and marsupial mammals, which hold their testes in an external scrotum."
Personally, I think since all the changes in the world are affecting the natural environment adaptive traits are important so that they can help maximize its reproductive success so its species can survive.
Hey there! Here is your answer: Horseshoe crab is considered living fossils because they have existed unchanged for about 445 million years. They are usually not crab; they are not closely related to lobsters or crab. ... Horseshoe crab looks is almost the same with their ancient relatives despite the fact that they have been around for so long. I hope this helped! Your fellow Brainly user, GalaxyGamingKitty. (THE FOLLOWING INFORMATION HAS BEEN USED FROM GOOGLE)