For a critical study of secondary growth in plants, which one of the following pairs is

suitable:

1. Sugarcane and sunflower

2. Teak and pine

3. Deodar and fern

4. Wheat and maiden hair fern

What is the destiny of primary xylem in a dicot root showing extensive secondary growth?

1. It is retained in the centre of the axis

2 It gets crushed

3. May or may not get crushed

4. It gets surrounded by primary phloem

Anatomically fairly old root is distinguished from dicotyledonous stem by

1. Position of Protoxylem

2. Absence of secondary xylem

3. Absence of secondary phloem

4. Presence of cortex

Secondary growth is because of

1. vascular cambium

2. cork cambium

3. lateral meristem

4. All of the above

In dicot root the complete ring of vascular bundle is formed by

(1)conjunctive tissue

(2)pericycle

(3)Endodermis

(4)Both A and B

The shape of the vascular bundle is __________in the beginning and later it becomes ___________in dicot root.

(1)wavy, circular

(2)circular, wavy

(3)circular , rectangular

(4)wavy, and trapezoid

Secondary growth occurs in

(1)dicot root and stem of angiosperms

(2)dicot root and stem of gymnosperms

(3)monocot roots

(4)Both 1 and 2