13.3 Phosphate cycle

Question 1

where is phosphate found in living organisms

Answer 1

component of ATP, Phospholipids, nucleic acids

Question 2

what does phosphate exist mostly as

Answer 2

phosphate ions (PO4) 3-
in sedimentary rock deposits

Question 3

phosphate cycle

Answer 3

weathering and erosion dissolves phosphate ions in sedimentary rock -> absorbed by plants -> animals which feed on plants -> excess ions excreted/ death of plants and animals-> decomposers release phosphate ions into water or soil (some phosphate ions remain in bone or shell -> long time to break down) ->phosphate ions return to sea via rivers to form sedimentary rock again

Question 4

role of mycorrhizae

Answer 4

fungi which act like extension of the plant root system (increasing surface area)
acts as a sponge holding water and minerals nearby roots
helps plant resist drought and improves uptake of scarce mineral ions