Question

Which one among the following statements correctly describes a tracheid? 

(a) Lignin is deposited in the cellulose wall to form annular or spiral thickenings 

(b) Dead, single cells with hard and lignified walls 

(c) Both (a) and (b) 

(d) None of the above

Answer 1

Answer is (b) Dead, single cells with hard and lignified walls

The statement (b) correctly describes a tracheid. Tracheid is a type of cell in the xylem. Their main function is conduction of sap. These are elongated or tube-like cells with thick and lignified walls and tapering ends. These are dead and the inner layer of the cell walls have thickenings.