Guard cells help in:
1. protection against grazing
2. transpiration
3. guttation
4. fighting against infection
Palisade parenchyma is absent in leaves of:
1. Sorghum
2. mustard
3. soybean
4. gram
Passage cells are thin-walled cells found in:
1. | endodermis of roots facilitating rapid transport of water from cortex to pericycle |
2. | phloem elements that serve as entry points for substances for transport to other plant parts |
3. | testa of seeds to enable emergence of growing embryonic axis during seed germination |
4. | central region of style through which the pollen tube grows towards the ovary |
A common structural feature of vessel elements and sieve tube elements is:
1. thick secondary walls
2. pores on lateral walls
3. presence of P-protein
4. enucleate condition
Anatomically, fairly old dicotyledonous root is distinguished from the dicotyledonous stem by:
1. absence of secondary xylem
2. absence of secondary phloem
3. presence of cortex
4. position of protoxylem
In barley stem, vascular bundles are:
1. open and scattered
2. closed and scattered
3. open and in a ring
4. closed and radial
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
The chief water conducting elements of xylem in gymnosperms are:
1. vessels
2. fibres
3. transfusion tissue
4. tracheids
1. mitochondria
2. endoplasmic reticulum
3. chloroplasts
4. cytoskeleton