I believe the answer in the blank should be protostar
Explanation:
Irreducible complexity (IC) involves the idea that certain biological systems cannot evolve by successive small modifications to pre-existing functional systems through natural selection.
The different levels of organisation within the biosphere, from the smallest to largest are:
1. Individual, species or creatures
the organisms
2. population
The entire populace
3. community
The total population at a given point in time and place.
4. ecosystem
The biotic and abiotic factors that are interacting.
5. biome
The ecosystems that share the same characeristics and abiotic factors.
6. biosphere
The entire living and nonliving organism in the planet earth, from prokaryotic cells to eukaryotic cells and how organic compounds from its enviroment aid in their survival