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

The common medullary rays between dicot stem and root is

(1)primary medullary rays

(2)secondary medullary rays

(3)Both A and B

(4)None of the above

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

Lenticels are present in

(1)stem only

(2)root only

(3)Both A and B

(4)root, stem and leaf

The more correct function of the medullary rays in dicot roots are

(1) water conduction only

(2)food conduction only

(3)food and water conduction

(4) food and water conduction in radial direction