Embryologist study embryos because Embryology is central to evolutionary developmental biology ("evo-devo"), which studies the genetic control of the development process (e.g. morphogens), its link to cell signalling, its roles in certain diseases and mutations, and its links to stem cell research.
Answer:
Competition between individuals of different species is known as interspecific competition.
It helps get rid of carbon dioxide.
Took me a while to understand any of this XD