Question

The following diagrams show the types of secondary thickening in the xylem vessels. Identify the types labelled from A-F. Choose the correct option from those given

• A. A-Spiral, B-Annular, C-Reticulate, D-Scalariform, E-Pitted with border, F-Pitted, simple
• B. A-Annular, B-Spiral, C-Scalariform, D-Reticulate, E-Pitted with border, F-Pitted, simple
• C. A-Annular, B-Spiral, C-Scalariform, D-Reticulate, E-Pitted, simple, F-Pitted with border
• D. A-Spiral, B-Annular, C-Scalariform, D-Reticulate, E-Pitted with border, F-Pitted, simple

Answer 1

The correct option is B A-Annular, B-Spiral, C-Scalariform, D-Reticulate, E-Pitted with border, F-Pitted, simple

After the growth of the xylem vessels has stopped, secondary wall materials are deposited on these cells. This happens when the xylem vessels are maturing. The vessels are dead cells at maturity and conduct water. The walls show different patterns of lignification A-annular, B-spiral, C-scalariform, D-reticulate, E-pitted with border and F-pitted simple.