This phylum includes the vertebrates, together with several closely related invertebrates. They are united by having, at some stage in their life, a notochord, a hollow dorsal nerve cord, pharyngeal slits and a muscular tail extending past the anus.

Chordates

Explanation:

Chordates (phylum Chordata) include the vertebrates, together with several closely related invertebrates.

the correct answer is:

a population changes in response to a change in the environment.

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation: