Plant Kingdom: Class 11 Biology Q&A
59 free answers on Plant Kingdom (Biology) for Class 11 students, across CBSE, ICSE and State boards. Includes questions such as “What is lignin in biology”, “what are insectivorous plants?”, “How do autotrophs obtain CO₂ and nitrogen (H₂O) to make their food?”
Question & Answer
Questions
- BiologyClass 11All
What is lignin in biology
All vascular plants possess lignin in their cells, cell walls, and intercellular spaces. Lignin is what provides food its fibre content, giving vegetables their delicious crunch and giving trees their woody appearance. The word "lignin" is very self-explanatory since it derives from the Latin word for "wood". Lignin helps plants stay upright by strengthening the cell walls and preventing them from collapsing, which is essential for the transportation of liquids throughout the plant (just thin
- BiologyClass 11All
what are insectivorous plants?
Insectivorous plants, also known as carnivorous plants, are a group of plants that have adapted to obtain nutrients, particularly nitrogen and sometimes other minerals, from insects and other small creatures. These plants typically grow in environments with nutrient-poor soils where they struggle to acquire enough nutrients through their roots alone. To compensate for this, they have evolved various mechanisms to capture, digest, and absorb nutrients from insects and other small organisms. Th
- BiologyClass 11All
How do autotrophs obtain CO₂ and nitrogen (H₂O) to make their food?
Autotrophs, particularly green plants, have evolved efficient mechanisms to obtain raw materials for photosynthesis: Carbon Dioxide (CO₂) Acquisition: Terrestrial Plants: Absorb CO₂ from the atmosphere through tiny pores called stomata located primarily on leaf surfaces (usually on the underside) Aquatic Plants: Dissolve CO₂ directly from water where it exists as dissolved gas or carbonic acid
- BiologyClass 11All
Write three characteristics of division Thallophyta.
Three key characteristics of Division Thallophyta: Simple, undifferentiated body structure: The plant body is a thallus without differentiation into true roots, stems, or leaves. This simple organization ranges from unicellular to multicellular forms but lacks specialized tissue systems found in higher plants. Absence of vascular tissue: Thallophytes lack xylem and phloem, the condu
- BiologyClass 11All
Give two basic differences between bryophytes and pteridophytes.
Two fundamental differences between bryophytes and pteridophytes: Vascular Tissue: Bryophytes: Lack vascular tissue (xylem and phloem), making them non-vascular plants. Water and nutrients move through simple diffusion and osmosis, limiting their size. Pteridophytes: Possess well-developed vascular tissue (xylem and phloem) for efficient transp
- BiologyClass 11All
What is porous wood and how does it differ from non-porous wood?
Porous wood refers to wood containing vessels (pores) visible to the naked eye or under low magnification, characteristic of dicotyledonous (hardwood) trees. These woods can be further classified as: Ring-porous wood: Large vessels concentrated in spring wood, forming distinct rings (e.g., oak, ash, elm). This arrangement provides excellent water conduction during peak growing seasons. Diffuse-porous wood: Ves
- BiologyClass 11All
Discuss the location of conjunctive tissue. Which cells constitute this tissue?
Conjunctive Tissue (also called connective tissue) is a component of the ground tissue system in roots. Location: In angiosperm roots with radial vascular bundles: Located in the patches between xylem and phloem Since xylem and phloem occupy different radii, the intervening spaces contain conjunctive tissue <st
- BiologyClass 11All
What are trichomes? Write their function in angiosperms.
Trichomes are epidermal appendages (outgrowths) found on the surface of plants. Structural Diversity: Based on Cellularity: Unicellular: Single-celled (root hairs, cotton fibers) Multicellular: Multi-celled (common in shoot systems) Based on Branching: Branched: Stellate (star-shaped) tri
- BiologyClass 11All
Give a brief description of guard cells
Guard cells are specialized epidermal cells that regulate stomatal aperture (pore). Structural Features: Shape Variation: Dicots:Bean-shaped (kidney-shaped) Monocots (Grasses):Dumb-bell shaped (with bulbous ends and narrow middle) Cellular Characteristics: <l
- BiologyClass 11All
What do you understand by protoxylem and protophloem?
Protoxylem and protophloem are the first-formed primary vascular tissues during plant development. Protoxylem: Definition: The earliest-formed primary xylem Cell characteristics:Narrow vessels/tracheids with annular or spiral thickening Flexibility: Extensible walls (allows elongatio
- BiologyClass 11All
What are the main water transporting elements in flowering plants?
Solution: The xylem tissue contains two primary water-conducting elements: Tracheids Vessels (vessel elements) Comparative Analysis: Feature Tracheids Vessels
- BiologyClass 11All
What do you mean by sclereids?
Sclereids (also called stone cells) are one of the two forms of sclerenchyma tissue. Structural Characteristics: Shape:Spherical, oval, or cylindrical Cell Wall:Highly thickened with extensive lignin deposition Lumen: Very narrow cavity (almost obliterated) <li
- BiologyClass 11All
Give a short description of parenchymatous cells.
Parenchyma is the most abundant and versatile simple permanent tissue in plants. Morphological Features: Shape: Generally isodiametric (spherical, oval, polygonal, rounded) Cell Wall:Thin, cellulosic primary walls Intercellular Spaces: May be closely packed or have small to large air
- BiologyClass 11All
What are the different types of meristems found in flowering plants w.r.t. position? Name them and describe any one.
Based on position in the plant body, meristems are classified as: Apical meristems Intercalary meristems Lateral meristems Detailed Description of Apical Meristems: Definition: Meristems located at the tips (apices) of roots and shoots. Characteristics: Shape: D
- BiologyClass 11All
Which type of cells are found in the secondary cortex?
Parenchymatous cells Formation & Structure: Produced by phellogen (cork cambium) towards the inner side Also called phelloderm Living cells with thin cellulosic walls Store nutrients and provide flexibility to the bark
- BiologyClass 11All
Give one function of the heartwood.
Provides mechanical support to the stem. Additional Functions: Structural integrity: Prevents buckling under wind stress No conduction: Dead cells filled with tannins, resins, oils Decay resistance: Aromatic compounds repel microorganisms and insects Commercial value: Used in furniture (teak, mahogany) Contrast with
- BiologyClass 11All
Which type of growth takes place in plants with the help of lateral meristems?
Secondary growth (increase in girth/diameter) Process Overview: Lateral meristems include: Vascular cambium → produces secondary xylem (wood) and secondary phloem Cork cambium (Phellogen) → produces cork (phellem) and secondary cortex (phelloderm) Taxonomic Distribution: Common in dicots and gymnosperms; absent in mos
- BiologyClass 11All
Name the material deposited on the radial and tangential walls of endodermal cells.
Suberin Biochemical Nature: Suberin is a lipophilic (waxy) biopolymer composed of: Long-chain fatty acids Phenolic compounds Glycerol Physiological Role: Forms Casparian strips that create an impermeable barrier, forcing water and minerals through the symplastic pathway (cell-to-cell), enabling selective uptake and pr
- BiologyClass 11All
Which type of arrangement of vascular bundles is seen in the roots of angiosperms?
Radial arrangement Structural Details: In radial vascular bundles: Xylem and phloem lie on different radii Alternating patches of xylem and phloem Conjunctive tissue (parenchyma) separates them Exarch protoxylem (towards periphery) Functional Advantage: This arrangement facilitates efficient lateral
- BiologyClass 11All
Define epidermis.
Epidermis is the outermost single-layered protective tissue of the primary plant body (roots, stems, leaves). Comprehensive Definition: The epidermis comprises: Compactly arranged parenchymatous cells (no intercellular spaces) Cuticle on the outer surface (waxy cutin layer) Stomata for gas exchange Trichomes (epiderma