Explanation:

About Biogeochemical Cycling

! Biogeochemical cycle, any of the natural pathways by which essential elements of living matter are circulated.

The term biogeochemical is a contraction that refers to the consideration of the biological, geological, and chemical aspects of each cycle. Elements within biogeochemical cycles flow in various forms from the nonliving (abiotic) components of the biosphere to the living (biotic) components and back. In order for the living components of a major ecosystem (e.g., a lake or a forest) to survive, all the chemical elements that make up living cells must be recycled  continuously. Each biogeochemical cycle can be considered as having a reservoir (nutrient) pool—a larger, slow- moving, usually abiotic portion—and an  exchange (cycling) pool—a smaller but more-active portion concerned with the rapid exchange between the biotic and abiotic aspects of an ecosystem.

! Statement 1 is incorrect: Only materials flow are represented in these cycles. Energy flow is represented in pyramids.

! Based on the replacement period, a nutrient cycle is referred to as Perfect or Imperfect cycle.  A perfect nutrient cycle is one in which nutrients are replaced as fast as they are utilized. Most gaseous cycles are generally considered as perfect cycles.  In contrast sedimentary cycles are considered relatively imperfect, as some nutrients are lost from the cycle and get locked into sediments and so become unavailable for immediate cycling.

! Based on the nature of the reservoir, there are two types of cycles namely-

 Statement 2 is correct: Gaseous Cycle — where the reservoir is the atmosphere or the hydrosphere — water cycle, carbon cycle, nitrogen cycle, etc. and 

Sedimentary Cycle — where the reservoir is the earth’s crust [elements mostly found in earth’s crust] —phosphorous cycle, sulphur cycle, calcium cycle, magnesium cycle etc.

! Statement 3 is correct: Also, in Carbon cycle, the CO2 is released into the environment after the biodegradation of dead organic matter.