Vascular bundles in monocotyledons are considered closed because

1.	a bundle sheath surrounds each bundle
2.	cambium is absent
3.	there are no vessels with performations
4.	xylem is surrounded all around by phloem

You are given a fairly old piece of dicot stem and a dicot root. Which of the following anatomical structures will you use to distinguish between the two?
1. Secondary xylem
2. Secondary phloem
3. Protoxylem
4. Cortical cells

Interfascicular cambium develops from the cells of ?

1. medullary rays

2. xylem parenchyma

3. endodermis

4. pericycle

The common bottle cork is a product of

(1) Dermatogens

(2) phellogen

(3) xylem

(4) vascular cambium

Companion cells are closely associated with

(1) sieve elements

(2) vessel elements

(3) trichomes

(4) guard cells

Closed vascular bundles lack

1. ground tissue

2. conjunctive tissue

3. cambium

4. pith

Water containing cavities in vascular bundles are found in

1. sunflower
2. maize
3. Cycas
4. Pinus

Ground tissues includes

In land plants, the guard cells differ from other epidermal cells in having:-

1. mitochondria

2. endoplasmic reticulum

3. chloroplasts

4. cytoskeleton

The cork cambium, cork and secondary cortex are collectively called

1. phellogen

2. periderm

3. phellem   

4. phelloderm