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Revision Notes

External Morphology - Plants — Revision Notes

Telangana Open School (TOSS) · Class 12 · Biology

External Morphology - Plants revision notes for Telangana Open School (TOSS) Class 12 Biology: 4 topics in quick points.

53 questions25 flashcards5 concepts

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Key Topics to Revise

1

Root System

  • Root develops from the radicle of the embryo and is positively geotropic but negatively phototropic.
  • It lacks nodes and internodes and is generally non-green.
  • Functions: Anchorage, absorption of water and minerals, storage, respiration, and nitrogen fixation.
2

Stem and Leaf Morphology

  • Stem develops from the plumule and is the aerial part with nodes and internodes.
  • Functions: Support, conduction, storage, and vegetative propagation.
  • Stem modifications: Rhizome (ginger), tuber (potato), bulb (onion), runner (Cynodon), sucker (mint), tendrils (grapevine), thorns (Bougainvillea), and photosynthetic stems (Opuntia).
3

Flower and Inflorescence

  • Flower is a modified shoot and the reproductive unit of angiosperms.
  • Inflorescence types: Racemose (acropetal), Cymose (basipetal), and Special types (e.g., Ficus).
  • Flower symmetry: Actinomorphic (radial), zygomorphic (bilateral), asymmetric.
4

Plant Families and Economic Importance

  • Fabaceae: Pea family — zygomorphic flowers, papilionaceous corolla, diadelphous stamens, marginal placentation, fruit is a pod.
  • Solanaceae: Potato family — actinomorphic flowers, gamopetalous corolla, epipetalous stamens, bilocular ovary, fruit is berry or capsule.
  • Liliaceae: Lily family — monocotyledonous, trimerous flowers, tepals, superior ovary, axile placentation, fruit is capsule or berry.

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Full Notes

Key Concepts

The root is the underground partThe stem is the aerial partLeaves are lateralInflorescence is the arrangement of flowersPlacentation refers to the arrangement

Frequently Asked Questions

What are the important topics in External Morphology - Plants for Telangana Open School (TOSS) Class 12 Biology?
Key topics in External Morphology - Plants include Root System, Stem and Leaf Morphology, Flower and Inflorescence, Plant Families and Economic Importance. Study these first, then practise questions on each for the Telangana Open School (TOSS) Class 12 board exam.
How should I revise External Morphology - Plants for the Telangana Open School (TOSS) Class 12 board exam?
Learn the core ideas first, then work through the 53 practice questions on External Morphology - Plants. Revise definitions regularly and use flashcards for quick recall before the exam.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.

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