Ecology that focuses on dynamic changes occurring in one species is ecology. 1) population 2) applied 3)systems

1) population

Explanation:

Ecology of population is a sub-discipline of ecology that concerns with the dynamics of population of the species, interaction of the population with the environment, with other species and among members of the same species. It studies how size of the population change over area and time.  

Therefore, on the basis of the above description, ecology that focuses on dynamic changes occurring in one species is called as population ecology.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.

the supermassive black hole is in the middle of the galaxy.