IB ESS 2026 Topic 5 ACTUAL UPDATED QUESTIONS AND CORRECT ANSWERS
Soil The upper layer of earth in which plants grow, a black or dark brown material
typically consisting of a mixture of organic substances, clay, and rock particles.
NPK A common abbreviation for nitrogen (N), phosphorus (P), and potassium (K),
which are essential nutrients for plant growth.
, Decomposition The process by which organic substances are broken down into simpler organic
or inorganic matter, often involving microorganisms.
Humus A dark organic material in soil produced by the decomposition of plant and
animal matter, essential for soil fertility.
Pedosphere The outermost layer of the Earth that is composed of soil and is a critical
component of the Earth's system.
Lithosphere The rigid outer part of the Earth, consisting of the crust and upper mantle, which
includes soil and rock.
Biosphere The global sum of all ecosystems, where life exists, including land, water, and the
atmosphere.
Inorganic Nutrients Mineral nutrients that are not derived from living organisms, essential for plant
growth.
Atmosphere The layer of gases surrounding the Earth, crucial for weather, climate, and
supporting life.
Hydrosphere All the water on Earth, including oceans, rivers, lakes, and water vapor in the
atmosphere.
Minerals Naturally occurring inorganic substances that are essential for plant and animal
life found in soil.
Detritivores Organisms that feed on dead organic matter, playing a key role in decomposition.
Detritus Dead organic matter, including decomposing plant and animal material.
Saprotrophs Organisms that obtain nutrients by feeding on dead or decaying organic matter.
Soil The upper layer of earth in which plants grow, a black or dark brown material
typically consisting of a mixture of organic substances, clay, and rock particles.
NPK A common abbreviation for nitrogen (N), phosphorus (P), and potassium (K),
which are essential nutrients for plant growth.
, Decomposition The process by which organic substances are broken down into simpler organic
or inorganic matter, often involving microorganisms.
Humus A dark organic material in soil produced by the decomposition of plant and
animal matter, essential for soil fertility.
Pedosphere The outermost layer of the Earth that is composed of soil and is a critical
component of the Earth's system.
Lithosphere The rigid outer part of the Earth, consisting of the crust and upper mantle, which
includes soil and rock.
Biosphere The global sum of all ecosystems, where life exists, including land, water, and the
atmosphere.
Inorganic Nutrients Mineral nutrients that are not derived from living organisms, essential for plant
growth.
Atmosphere The layer of gases surrounding the Earth, crucial for weather, climate, and
supporting life.
Hydrosphere All the water on Earth, including oceans, rivers, lakes, and water vapor in the
atmosphere.
Minerals Naturally occurring inorganic substances that are essential for plant and animal
life found in soil.
Detritivores Organisms that feed on dead organic matter, playing a key role in decomposition.
Detritus Dead organic matter, including decomposing plant and animal material.
Saprotrophs Organisms that obtain nutrients by feeding on dead or decaying organic matter.
