In Earth’s history, what might the cooling of the Earth and the resulting change from a forested to a grassy landscape have made adaptive in humans?

Sharks have cartilaginous skeletons because bone-forming ability had not yet evolved in vertebrates when they originated.  

All of the following plant parts are organ systems EXCEPT:

As a new curator for a large public aquarium in your city, you are in charge of correctly identifying some of the animals presently in your care.  You have two adult animals in tanks in front of you, and you know that one is a lamprey, and the other is a hagfish.  Which feature would allow you to correctly identify each animal?

Hiatal hernia is a kind of oropharyngeal dysphasia.

43. Which of the following is not a symptom of dysphasia?

22. Which middle ear muscle is attached to the manubrium of the malleus?

17. Which of the following is NOT one of the three middle ear ossicles?

38. Which auditory brainstem region is the first to receive information from both ears (binaural interaction)?

18. Which is the largest bone of the three ossicles?