The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is

1. differentiating	2. maturing
3. elongating	4. widening

In barley stem, vascular bundles are
1. closed and radial
2. open and scattered
3. closed and scattered
4. open and in a ring

Palisade parenchyma is absent in leaves of
1. Gram
2. Sorghum
3. Mustard
4. Soybean

Anatomically, fairly old dicotyledonous root is distinguished from the dicotyledonous stem by
1. Position of protoxylem
2. Absence of secondary xylem
3. Absence of secondary phloem
4. Presence of cortex

Heart wood differs from sapwood in
1. Absence of vessels and parenchyma
2. Having dead and non-conducting elements
3. Being susceptible to pests and pathogens
4. Presence of rays and fibres

Which one of the following is not a lateral meristem
1. Interfascicular cambium
2. Phellogen
3. Intercalary meristem
4. Intrafascicular cambium

In land plants, the guard cells differ from other epidermal cells in having
1. Cytoskeleton
2. Mitochondria
3. Endoplasmic reticulum
4.Chloroplasts

The cork cambium, cork and secondary cortex are collectively called
1. Phelloderm
2. Phellogen
3. Periderm
4. Phellem

Some vascular bundles are described as open because these
1. are surrounded by pericycle but no endodermis
2. are capable of producing secondary xylem and phloem
3. possess conjunctive tissue between xylem and phloem
4. are not surrounded by pericycle

Companion cells are closely associated with
1. Sieve elements
2. Vessel elements
3. Trichomes
4. Guard cells