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
Which of the following is known as living mechanical tissue
(1)parenchyma
(2)collenchyma
(3)sclerenchyma
(4)All of the above
Which one is true of collenchyma?
(1)forms the hypodermis of dicot stem
(2) present below epidermis in layers or patches
(3)thickened corners due to cellulose, hemicellulose, and pectin deposition
(4)All of the above
The main mechanical tissue of the plant is
(1)sclerenchyma
(2)collenchyma
(3)parenchyma
(4)Both B and C
Sclerenchyma is
(1) dead and lignified
(2)consists of long, narrow, thick walled cells
(3)may be in the form of fibres and sclereids
(4)All of these