The brain's fear threat center is called the 1.the amygdala
2. the brain stem
3.the freeze response
4 the long path way

The anwser is:

1.(amygdala)

Hope this helps!

answer: a. a gene that causes a specific trait.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation