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. Conjuctive tissue
3. Cambium
4. Pith
Water containing cavities in vascular bundles are found in:
1. Sunflower
2. Maize
3. Cycas
4. Pinus
Gymnosperms are also called softwood spermatophytes because they lack:
1. Cambium
2. Phloem fibres
3. Thick-walled tracheids
4. Xylem fibres
1. all tissues except epidermis and vascular bundles
2. epidermis and cortex
3. all tissues internal to endodermis
4. all tissues external to endodermis
1. mitochondria
2. endoplasmic reticulum
3. chloroplasts
4. cytoskeleton
The chief water conducting elements of xylem in gymnosperms are:
1. vessels
2. fibres
3. transfusion tissue
4. tracheids
The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is:
1. maturing
2. elongating
3. widening
4. differentiating
In barley stem, vascular bundles are:
1. open and scattered
2. closed and scattered
3. open and in a ring
4. closed and radial