71.

A dicotyledonous plant forms crown gall when

• Agrobacterium tumefaciens comes in contact with the plant

• Agrobacterium rhizogenes comes in contact with the plant

• a specific part of DNA from the Ti-plasmid gets integrated with the plant chromosome

• a specific part of DNA from the Ri-plasmid gets integrated with the plant chromosome

Match the following Columns

Column I	Column II
A. Tracheids	1. Cells posses highly thickness walls with obliterates central lumen
B.  Vessels	2. Elongated tube like cells with thick lignified walls and tampering ends
C. Xylem parenchyma	3. Individual members are interconnected through perforations in their common walls
D. Xylem fibres	4. Cells are living with thin cellulosic cell walls.

The correct answer is

• A- 2; B- 3; C- 4; D- 1

• A- 2; B- 4; C- 1; D- 3

• A- 3; B- 2; C- 4; D- 1

• A- 2; B- 3; C- 1; D- 4

If there is more than one tunica layer in stem apex, which among the following is most likely to happen?

• All the layers will develop into epidermal cells

• Only the outer layer will develop into epidermal cells

• All the layers will develop into cortex

• Inner layer develops into cortex

Which of the following region of root is responsible for increase in length of root?

• Root cap region

• Meristematic region

• Region of elongation

• Mature region

The dark coloured dead wood present in the central region of old tree is

• spring wood

• heart wood

• sap wood

• cambium

Enucleated cells at maturity are

• palisade cells

• guard cells

• companion cells

• sieve elements

Atactostele vascular bundles are

• scattered in the ground tissue

• three in number

• in form of ting around

• broken vascular bundles

Which of the following clogs the cavity of the xylem vessels?

• Tylosis

• Cystolith

• Hydathode

• Raphide

Phloem parenchyma is absent in

• monocot stem

• dicot stem

• dicot root'

• dicot leaf

Grafting is not possible in monocots because they

• lack cambium

• have scattered vascular bundles

• have parallel venation

• are herbaceous