The cross-section shown in the given diagram shows the structure of a:
1. | Monocot stem | 2. | Monocot root |
3. | Dicot root | 4. | Dicot stem |
1. | In dicot root, initiation of lateral roots and vascular cambium during the secondary growth takes place in the pericycle |
2. | In monocot roots xylem bundles are usually more than six [polyarch] |
3. | In dicot stems vascular bundles are arranged in a ring |
4. | Monocot stem has a parenchymatous hypodermis |
Grass leaves curl inwards during very dry weather. Select the most appropriate reason from the following :
1. Tyloses in vessels
2. Closure of stomata
3. Flaccidity of bulliform cells
4. Shrinkage of air spaces in spongy mesophyll
1. | A - Adaxial epidermis | 2. | B - Phloem |
3. | C - Mesophyll | 4. | D - Abaxial epidermis |
Identify the incorrect comparison between monocots and dicots in general:
Character | Monocots | Dicots | |
1. | Leaves | Parallel venation | Reticulate venation |
2. | Roots | Primary root of short duration, replaced by adventitial roots forming fibrous or fleshy root systems | Develops from the radicle. Primary root often persists forming strong tap roots and secondary roots |
3. | Plant stem: Vascular bundles | Ring of primary bundles with cambium, differentiated into cortex and stele | Numerous scattered bundles in ground parenchyma, cambium mostly absent, no differentiation between cortical and stelar regions |
4. | Flowers | Parts in threes (trimerous) or multiples of three | Fours (tetramerous) or fives (pentamerous) |
Column I | Column II | ||
A. | Dicot stem | P. | Vascular bundles are arranged in a ring |
B. | Monocot stem | Q. | Pith is small or inconspicuous |
C. | Dicot root | R. | Vascular bundles are many and scattered in the ground tissue with no definite arrangement. |
D. | Monocot root | S. | Pith is large and well developed |
A | B | C | D | |
1. | Q | S | P | R |
2. | S | Q | R | P |
3. | P | R | Q | S |
4. | R | P | S | Q |
The vascular cambium normally gives rise to
1. | Phelloderm | 2. | Primary phloem |
3. | Secondary xylem | 4. | Periderm |
1. | Hypodermis | Sclerenchymatous |
2. | Endodermis | Starch sheath |
3. | Medullary rays | Parenchyma cells |
4. | Protoxylem | Endarch |
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 |
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 |