CBSE Class 11 Biology Short Answer Questions – Morphology of Flowering Plants (Chapter 5) | NCERT-Based

Course & Examination Details

Course: CBSE Class 11 Biology
Unit: Unit II – Structural Organisation in Animals and Plants
Chapter: Chapter 5 – Morphology of Flowering Plants
Prescribed By: CBSE Board (As per NCERT syllabus)
Question Type: Short Answer Questions (60–80 words)

Section I: Root (Questions 1–10)

Q1. Describe the structure and functions of the root.

Answer:
The root is the underground part of the plant axis developing from the radicle. It anchors the plant in soil, absorbs water and minerals, stores food in some plants, synthesizes growth regulators, and supports vegetative propagation. Roots also help in respiration and parasitism through specific modifications.

Q2. Explain the tap root system with examples.

Answer:
The tap root system originates from the radicle and consists of a main primary root with lateral secondary and tertiary branches. It is commonly found in dicotyledonous plants. Tap roots may store food in modified forms such as conical, fusiform, or napiform roots, as seen in carrot, radish, and turnip.

Q3. Write a short note on fibrous root system.

Answer:
In fibrous root system, the radicle is short-lived and replaced by numerous thin roots arising from the base of the stem. These roots form a dense mat and provide efficient absorption and anchorage. This root system is characteristic of monocotyledonous plants such as wheat, rice, and grasses.

Q4. What are adventitious roots? Mention their functions.

Answer:
Adventitious roots arise from parts other than the radicle, such as stem or leaves. They perform specialized functions including support (prop roots, stilt roots), respiration (pneumatophores), storage, parasitism, and vegetative propagation, enabling plants to survive under different environmental conditions.

Q5. Explain storage modifications of roots.

Answer:
Storage roots are modified to store reserve food materials. In tap roots, storage forms include conical, fusiform, and napiform types. In adventitious roots, storage occurs in sweet potato. These modifications help plants survive adverse conditions and provide nourishment during new growth phases.

Q6. Describe prop roots and their significance.

Answer:
Prop roots are adventitious roots that arise from branches and grow vertically downward into the soil. They provide additional mechanical support to large plants with spreading branches. Banyan tree is a common example where prop roots help in anchoring and increasing stability.

Q7. What are stilt roots? Give examples.

Answer:
Stilt roots are adventitious roots arising from the lower nodes of the stem, growing obliquely downward into the soil. They provide mechanical support to plants growing in loose or marshy soils. Stilt roots are commonly seen in maize and sugarcane plants.

Q8. Explain pneumatophores.

Answer:
Pneumatophores are specialized respiratory roots found in mangrove plants growing in waterlogged and marshy soils. These roots grow vertically upward and bear lenticels, which facilitate gaseous exchange when the soil is deficient in oxygen.

Q9. What are haustorial roots?

Answer:
Haustorial roots are parasitic root modifications found in plants like Cuscuta. These roots penetrate the host plant tissues and absorb water and nutrients directly from the host, thereby supporting the parasitic mode of nutrition.

Q10. How do roots help in vegetative propagation?

Answer:
Certain roots can give rise to new shoots and plants through vegetative propagation. For example, adventitious buds develop on roots of sweet potato and dahlia, enabling the formation of new plants without seeds.

Section II: Stem (Questions 11–20)

Q11. Describe the structure and functions of the stem.

Answer:
The stem is the ascending aerial part of the plant axis bearing branches, leaves, flowers, and fruits. It conducts water and minerals from roots to leaves and transports food from leaves to other parts. It also provides mechanical support and undergoes modifications for storage and propagation.

Q12. Explain underground stem modifications with examples.

Answer:
Underground stems such as rhizome, tuber, bulb, and corm are modified for storage, perennation, and vegetative propagation. Rhizome is horizontal, tuber is swollen with eyes, bulb has fleshy scale leaves, and corm is solid and vertical.

Q13. What is a rhizome? Write its features.

Answer:
A rhizome is a horizontal underground stem bearing nodes, internodes, scale leaves, and axillary buds. It stores food and helps in vegetative propagation. Ginger is a common example of a rhizome.

Q14. Explain tuber as a stem modification.

Answer:
A tuber is a swollen underground stem used for storage of food. It bears eyes, which are nodes with axillary buds. Potato is an example. Tubers help in vegetative propagation and survival during unfavourable seasons.

Q15. Describe bulb with an example.

Answer:
A bulb is an underground stem modification consisting of a short disc-like stem and fleshy scale leaves that store food. Onion is a common example. Bulbs help in perennation and vegetative reproduction.

Q16. What are aerial stem modifications?

Answer:
Aerial stem modifications include tendrils for climbing, thorns for protection, and phylloclades for photosynthesis and water storage. These adaptations help plants survive in different environmental conditions.

Q17. Explain phylloclade.

Answer:
Phylloclade is a flattened or cylindrical stem modification that performs photosynthesis and stores water. Leaves are reduced to spines to reduce transpiration. Opuntia is a common example of phylloclade.

Q18. What are subaerial stems?

Answer:
Subaerial stems partially grow above the soil surface and help in vegetative propagation. Examples include runner, stolon, sucker, and offset. These structures enable rapid spread of plants.

Q19. What is a runner?

Answer:
A runner is a subaerial stem that grows horizontally on the soil surface. Nodes develop adventitious roots and shoots, forming new plants. It is commonly seen in lawn grass.

Q20. State the importance of stem modifications.

Answer:
Stem modifications help in storage of food, vegetative propagation, protection, photosynthesis, and survival during unfavourable environmental conditions, enhancing adaptability of plants.

Section III: Leaf (Questions 21–30)

Q21. Describe the structure of a leaf.

Answer:
A leaf consists of leaf base, petiole, and lamina. The lamina is broad and flat with veins and veinlets. Leaves are the main photosynthetic organs and also help in transpiration and gaseous exchange.

Q22. Explain venation and its types.

Answer:
Venation refers to the arrangement of veins in the leaf lamina. It is of two types: reticulate venation, forming a network in dicots, and parallel venation, where veins run parallel in monocots.

Q23. Define phyllotaxy and its types.

Answer:
Phyllotaxy is the arrangement of leaves on the stem or branch. It is of three types: alternate, opposite, and whorled. Proper phyllotaxy ensures maximum exposure to sunlight.

Q24. Differentiate between simple and compound leaves.

Answer:
A simple leaf has an undivided lamina, whereas a compound leaf has its lamina divided into distinct leaflets. In compound leaves, leaflets do not bear axillary buds.

Q25. Explain compound leaves with examples.

Answer:
Compound leaves may be pinnately compound or palmately compound. In pinnate type, leaflets are arranged along a rachis, as in neem. In palmate type, leaflets arise from a common point, as in silk cotton.

Q26. Write a short note on leaf modifications.

Answer:
Leaves may modify into tendrils for climbing, spines for protection, storage leaves for storing food, and insectivorous leaves for trapping insects. These modifications help plants adapt to their environment.

Q27. What is reticulate venation?

Answer:
Reticulate venation is a type of venation where veins and veinlets form a network in the leaf lamina. It is typically found in dicotyledonous plants.

Q28. What is parallel venation?

Answer:
Parallel venation is a type of venation where veins run parallel to each other throughout the lamina. It is characteristic of monocotyledonous plants.

Q29. Explain the role of leaves in transpiration.

Answer:
Leaves regulate transpiration through stomata, helping in cooling of the plant body, absorption of minerals, and maintenance of water balance.

Q30. Why are leaves called photosynthetic organs?

Answer:
Leaves contain chlorophyll in chloroplasts, enabling them to trap sunlight and synthesize food through photosynthesis, making them primary food-producing organs.

Section IV: Inflorescence, Flower, Fruit, Seed & Floral Formula (Questions 31–50)

Q31. Define inflorescence and its significance.

Answer:
Inflorescence is the arrangement of flowers on the floral axis. It influences pollination efficiency, flowering sequence, and identification of plant species.

Q32. Explain racemose inflorescence.

Answer:
In racemose inflorescence, the main axis continues to grow and bears flowers in acropetal succession. Younger flowers are at the apex and older ones at the base.

Q33. Describe cymose inflorescence.

Answer:
Cymose inflorescence has a determinate main axis that ends in a flower. Flowers are arranged in basipetal succession, with older flowers at the apex.

Q34. What are special types of inflorescence?

Answer:
Special inflorescences include cyathium, hypanthodium, and verticillaster, where flowers show unique structural arrangements for effective pollination.

Q35. Describe the structure of a flower.

Answer:
A flower consists of four whorls: calyx, corolla, androecium, and gynoecium, arranged on the thalamus. It is the reproductive organ of angiosperms.

Q36. Explain types of flowers based on sexuality.

Answer:
Flowers may be bisexual, containing both reproductive organs, or unisexual, having either stamens or carpels. This classification affects pollination strategies.

Q37. What is actinomorphic flower?

Answer:
An actinomorphic flower shows radial symmetry and can be divided into equal halves by more than one vertical plane passing through the centre.

Q38. Explain hypogynous, perigynous, and epigynous flowers.

Answer:
Hypogynous flowers have a superior ovary, perigynous have half-inferior ovary, and epigynous flowers have inferior ovary based on floral part attachment.

Q39. Define fruit and its functions.

Answer:
Fruit is a mature ovary formed after fertilisation. It protects seeds and helps in seed dispersal by various agents.

Q40. Explain types of fruits.

Answer:
Fruits are classified into simple, aggregate, and multiple fruits based on ovary structure and flower arrangement.

Q41. What is a seed? Describe its structure.

Answer:
A seed is a fertilised ovule containing an embryo, seed coat, and stored food. It ensures propagation and survival of plants.

Q42. Differentiate between albuminous and exalbuminous seeds.

Answer:
Albuminous seeds retain endosperm at maturity, while exalbuminous seeds store food in cotyledons and lack endosperm.

Q43. Define floral formula.

Answer:
Floral formula is a symbolic representation showing symmetry, sexuality, number, and fusion of floral parts, aiding in identification.

Q44. Explain the significance of floral formula.

Answer:
Floral formula helps in quick understanding and comparison of floral structure, making plant classification and examination revision easier.

Q45. What is a floral diagram?

Answer:
A floral diagram is a graphical representation showing arrangement and relationship of floral parts with respect to the mother axis.

Q46. Why is morphology important in plant classification?

Answer:
Morphological characters help identify plants, classify them into families, and understand evolutionary relationships.

Q47. State the importance of this chapter for examinations.

Answer:
This chapter is highly scoring due to direct NCERT questions, diagram-based problems, and terminology-focused answers.

Q48. How does inflorescence help in identification of plants?

Answer:
Inflorescence pattern is a key taxonomic character that distinguishes plant families and species.

Q49. What role does seed play in plant life cycle?

Answer:
Seeds ensure propagation, dispersal, dormancy, and survival of plants during unfavourable conditions.

Q50. Why is Morphology of Flowering Plants considered a foundational chapter?

Answer:
It builds the base for taxonomy, anatomy, physiology, and ecology, making it essential for higher studies in botany.