1. | Guard cells invariably possess chloroplasts and mitochondria |
2. | Guard cells are always surrounded by subsidiary cells |
3. | Stomata are involved in gaseous exchange |
4. | Inner walls of guard cells are thick |
Some vascular bundles are described as open because these:
1. | are not surrounded by pericycle |
2. | are surrounded by pericycle but no endodermis |
3. | are capable of producing secondary xylem and phloem |
4. | possess conjunctive tissue between xylem and phloem |
Given below is the diagram of a stomatal apparatus. In which of the following, all the four parts labelled as A, B, C and D are correctly identified:
A | B | C | D | |
1. | Guard cell | Stomatal aperture | Subsidiary Cell | Epidermal Cell |
2. | Epidermal Cell | Guard Cell | Stomatal aperture | Subsidiary cell |
3. | Epidermal Cell | Subsidiary Cell | Stomatal aperture | Guard Cell |
4. | Subsidiary Cell | Epidermal Cell | Guard Cell | Stomatal aperture |
Transport of food material in higher plants takes place through:
1. Transfusion tissue
2. Tracheids
3. Sieve elements
4. Companion cells
Compared to a dicot root, a monocot root has:
1. Many xylem bundles
2. Inconspicuous annual rings
3. Relatively thicker periderm
4. More abundant secondary xylem
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
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 |
Palisade parenchyma is absent in leaves of:
1. Sorghum
2. mustard
3. soybean
4. gram
Guard cells help in:
1. protection against grazing
2. transpiration
3. guttation
4. fighting against infection
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