Which is true about heartwood/duramen ?

a) It does not help in water and mineral conduction

b) It is dark coloured but soft

c) It has tracheary elements filled with tannins, resins, gums, oil, etc

d) It is a peripheral part

e) Sensitive to microbes and insects, hence least durable

Heart wood lose the ability of conduction due to tyloses and gaps are filled with various organic compounds such as oils, gums, resins, tannins, colouring agents and aromatic substances together called extractives. Hence the wood formed in earlier years becomes dark colour.heart wood is resistance to pests and impermeable to water and shows durability. The peripheral light coloured wood formed recently and carries conduction function but not having timber value is called laburnum or sap wood.