5.4: Phosphorus cycle

Question 1

Fully describe the phosphorus cycle

Answer 1

Phosphate ions trapped in rocks are weathered away and dissolve into water bodies/into the soil where they are absorbed by plants used to make ATP and nucleic acid in plants, which is then eaten by animals and the phosphate ions are used to make ATP and nucleic acid in animals, animals’ death and excretion -> decomposition by saprobiotic bacteria to decompose. Phosphate ions from wastes and remains are either absorbed by soil or leached into water bodies where they settle to form sedimentary rocks

Question 2

Give two reasons why a high concentration of phosphate ions in the soil would increase the growth rate of a plant

Answer 2

increased ATP synthesis which provides energy for growth (cell division)
increased synthesis of DNA for faster mitosis (growth)