3. What determines how many species live in a given place? And, what determines how large each population can grow?

Every stable population has one or more factors that limit its growth. A limiting factor determines the carrying capacity for a species. A limiting factor can be any biotic or abiotic factor: nutrient, space, and water availability are examples. The size of a population is tied to its limiting factor.  The environment, what food is there and what predators live there. How much food they get and if they are decreasing from weather, predators etc.

Explanation:

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.

correct answer is a. and d.