When does the placenta begin to form?
O
A. In the second trimester
O
B. At the end of the third trimester
O
C. A few days after fertilization
O
D. At the end of the first trimester

Based on the body structures of these animals, which two conclusions are scientifically the skeletal structure of the gorilla and chimpanzee suggest a common evolutionary ancestry. the dog and frog share a closer evolutionary ancestry than the gorilla and chimpanzee. the dog is more closely related to the frog than it is to the chimpanzee. all four organisms share a common vertebrate ancestor.