Briefly explain how radial symmetry and the lack of cephalization usually associated with it can have adaptive value for sessile animals and be favored by natural selection.

Metamorphic rocks are formed when sedimentary or igneous rocks are subjected to heat or pressure and recrystallize without melting. which of the following rocks results from the metamorphism of limestone? a. granite b. slate c. sandstone d. marble

Which of the following is a main difference in cell structure between an onion cell and a human cheek cell? a. an onion cell contains one nucleus, whereas a human cheek cell contains two nuclei. b. an onion cell has a cell wall. c. a human cheek cell contains chloroplasts. d. there is no difference between an onion cell and a human cheek cell. you for your.

The influenza virus cause the flu, but not other diseases. why?