In plants the replacement of the outer cortical and epidermal layers when they are broken are because of the

(1)Cork cambium

(2)vascular cambium

(3)Phellogen

(4)Both A and C

The cork is impervious to ______due to __________deposition in the cell wall.

(1)water, suberin

(2)water, lignin

(3)water, wax

(4)water, cellulose

Bark non-technically refers to tissues which lies

(1)exterior to vascular cambium

(2)exterior to cork cambium

(3)exterior to primary phloem

(4)All of the above

How many of the followings constitute the bark?

( secondary phloem, secondary cortex, cork cambium, complimentary cells, epidermis, periderm )

(1)6

(2)5

(3)4

(4)3

Which of the following is true for lenticels

(1)lens shaped opening

(2) occur in most woody trees

(3)permit exchange of gases

(4)All of the above

The function of lenticels are

(1)exchange of gases

(2)helps in transpiration

(3)helps in vegetative reproduction

(4)Both a and b

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

In dicot roots, secondary phloem is formed towards the _________ and secondary xylem is formed towards the __________ by the activity of vascular cambium.

(1)periphery, centre

(2)centre, periphery

(3)innerside, outerside

(4)Both B and C

There are _________types of medullary rays formed in dicot roots during secondary growth.

(1)one

(2)two

(3)three

(4)many