the one with the most organism is domain
The kingdom level of classification contains the most diversity and number of organisms. It is the broadest level where organisms are grouped based on shared characteristics.
The highest level, called Domain, contains all of the other levels, and thus by default, contains the most organisms (all of them).
Bacteria
The most specific is genus
The genus Arthropoda(mosquitoes, flies, grasshoppers etc.) contains most organisms if u r concerned about animal kingdom
Most plants and animals live in the Sunlit Zone.
Leaching Zone
Organisms within the same family are more closely related than those within the same order. Family is a higher classification level than order, so organisms within the same family share more recent common ancestry.
The bottom of the pyramid contains the most energy.
The category that most similiar organisms belong to is genus.
species
On an ecological pyramid or in a food chain, typically, the highest trophic levels have the least amount of energy from the sun available for the next highest level. In a typical food chain, this would be the tertiary consumer level.