Worksheet with Solutions: Morphology of Flowering Plants | Biology Class 11 - NEET PDF Download

Ans: Root cap

Ans: Phyllotaxy

Ans: Calyx

Ans: Parthenocarpic

Ans: Hilum

Ans: a-ii, b-i, c-iii, d-iv, e-v

Ans: (b) Direct elongation of the radicle

Ans: (b) Holding the leaf blade to light

Ans: (b) Cymose

Ans: (d) Vexillary

Ans: (c) Basal

Ans: (a) Both assertion and reason are true, and the reason is the correct explanation of the assertion.
The assertion is true, as dicotyledonous plants do indeed have reticulate venation. The reason is also true, as the veinlets in dicot leaves form a network pattern. The reason directly explains the assertion, as the network pattern is what defines reticulate venation in dicots. Thus, the correct answer is (a): "Both assertion and reason are true, and the reason is the correct explanation of the assertion."

Ans: (c) Assertion is true, but the reason is false.
The assertion is true because monocots generally have endospermic seeds. However, the reason is false because the endosperm is present in mature seeds of cereals like maize. Therefore, the correct answer is (c): "Assertion is true, but the reason is false."

Ans:The root system in flowering plants is classified into:

• Tap Root System: Formed by the elongation of the radicle, with secondary and tertiary roots (e.g., mustard). Common in dicotyledons.

• Fibrous Root System: Numerous thin, thread-like roots of equal size, replacing the primary root (e.g., maize). Typical in monocotyledons.

• Adventitious Root System: Roots arising from parts other than the radicle, such as stems or leaves (e.g., banyan for support).
  Modifications:

• Storage: Swollen roots for food storage (e.g., carrot in tap roots).

• Support: Prop roots in banyan or stilt roots in maize for mechanical support.

• Respiration: Pneumatophores in mangroves for gaseous exchange.

Ans: Flowers vary in symmetry and ovary position:

• Symmetry:

  • Actinomorphic: Can be divided into equal radial halves in any plane (e.g., mustard, datura). Exhibits radial symmetry.

  • Zygomorphic: Divisible into two similar halves in one vertical plane (e.g., pea, bean). Shows bilateral symmetry.

  • Asymmetric: Cannot be divided into similar halves by any plane (e.g., canna).

• Ovary Position:

  • Hypogynous: Ovary superior, other parts below (e.g., china rose).

  • Perigynous: Ovary half inferior, other parts at the same level (e.g., rose).

  • Epigynous: Ovary inferior, other parts above (e.g., sunflower ray florets).
    These variations aid in pollination and adaptation to different environments.
    
    

Ans: The region of elongation, located just above the meristematic region in the root, is where cells undergo rapid elongation and enlargement. This process drives the growth of the root in length, allowing it to penetrate deeper into the soil for better anchorage and absorption of water and minerals (e.g., in mustard roots).

Ans:

• Nodes: Regions on the stem where leaves, branches, or buds arise (e.g., in china rose). They are points of attachment.

• Internodes: Portions of the stem between two consecutive nodes. They determine the length and spacing of the stem (e.g., elongated in sunflower).

Ans: Stipules are small, leaf-like structures at the leaf base (e.g., in pea). They protect the young leaf or bud, may aid in photosynthesis if green, and in some cases, become modified for defense (spines) or support (tendrils).

Ans: Floral diagrams illustrate the number, arrangement, and relationships of floral parts (calyx, corolla, androecium, gynoecium) in a flower. They provide a visual summary of floral structure, aiding in classification and identification (e.g., mustard in Brassicaceae).

Ans: A drupe is a fleshy fruit with a single seed, developed from a monocarpellary superior ovary. It has a thin epicarp (skin), a fleshy mesocarp (edible part), and a hard endocarp (stone) enclosing the seed. Example: Mango.

Ans: The coleoptile is a sheath enclosing the plumule in monocotyledonous seeds (e.g., maize). It protects the emerging shoot during germination and helps it break through the soil surface.

Ans: A bracteate flower has a reduced leaf-like structure called a bract at the base of the pedicel, which may protect the flower or attract pollinators. Example: Mustard.

Ans: The Solanaceae family provides food (e.g., potato, tomato), spices (e.g., chilli), medicines (e.g., belladonna), fumigants (e.g., tobacco), and ornamentals (e.g., petunia), contributing significantly to agriculture and industry.

Ans: Venation, the arrangement of veins and veinlets in a leaf lamina, is crucial for:

• Structural Support: Veins provide rigidity to the leaf blade (e.g., in mustard).

• Transport: They act as channels for water, minerals, and photosynthates between the leaf and other plant parts.

• Classification: Venation patterns help distinguish monocotyledons from dicotyledons.
  Types:

• Reticulate Venation: Veinlets form a network, typical in dicotyledons (e.g., china rose, brinjal). It supports efficient nutrient distribution.

• Parallel Venation: Veins run parallel to each other, characteristic of monocotyledons (e.g., maize, wheat). It suits elongated, narrow leaves. These patterns reflect adaptations to photosynthetic and mechanical needs.

Ans: Phyllotaxy is the arrangement of leaves on a stem or branch, optimizing light capture and space utilization:

• Alternate: A single leaf arises at each node in an alternate manner, maximizing light exposure (e.g., china rose, sunflower).

• Opposite: A pair of leaves arises at each node, opposite each other, ensuring balanced light capture (e.g., guava, Calotropis).

• Whorled: More than two leaves form a whorl at a node, crowding leaves for efficient photosynthesis in dense canopies (e.g., Alstonia).
  These arrangements reduce shading among leaves, enhance photosynthesis, and support plant growth by optimizing resource use.

Ans: Inflorescence is the arrangement of flowers on the floral axis, influencing pollination and seed dispersal:

• Racemose: The main axis continues to grow, with flowers borne laterally in acropetal succession (e.g., mustard). It allows continuous flowering.

• Cymose: The main axis terminates in a flower, with flowers in basipetal order (e.g., jasmine). It limits growth but ensures early seed production.

• Solitary: A single flower at the shoot tip or axil (e.g., Solanum).
  These types reflect adaptations to pollinator attraction and reproductive strategies, with racemose suited for prolonged flowering and cymose for rapid reproduction.

Ans: Placentation is the arrangement of ovules within the ovary, impacting seed development and dispersal:

• Marginal: Ovules form two rows along the ventral suture in a unilocular ovary (e.g., pea). Maximizes ovule number in simple ovaries.

• Axile: Ovules attach to a central axis in a multilocular ovary (e.g., tomato, china rose). Supports multiple ovules per locule.

• Parietal: Ovules develop on the inner ovary wall, often with a false septum (e.g., mustard). Increases ovule capacity in unilocular ovaries.

• Free Central: Ovules on a central axis without septa (e.g., Dianthus). Efficient in small ovaries.

• Basal: A single ovule at the ovary base (e.g., sunflower). Suits single-seeded fruits. These variations optimize ovule protection and seed production, aiding reproductive success.

Ans:

• Dicotyledonous Seeds:

  • Cotyledons: Two, often fleshy, storing reserve food (e.g., gram, pea).

  • Endosperm: Usually absent in mature seeds (non-endospermic, e.g., bean).

  • Seed Coat: Has two layers (testa and tegmen) with a hilum and micropyle (e.g., castor).

  • Embryo: Large, with distinct radicle and plumule.

• Monocotyledonous Seeds:

  • Cotyledons: One, often shield-shaped (scutellum, e.g., maize).

  • Endosperm: Bulky, food-storing, present in mature seeds (endospermic, e.g., wheat).

  • Seed Coat: Membranous, often fused with the fruit wall, with an aleurone layer.

  • Embryo: Small, with coleoptile (plumule sheath) and coleorhiza (radicle sheath).
    Key Difference: Dicot seeds rely on cotyledons for food storage, while monocot seeds depend on endosperm, reflecting distinct germination strategies.