## CORE INFORMATION\n✓ **Answer**: A\n## CONCEPT FRAMEWORK\n**Primary Concept**: Plant Morphology\n**Related Topics**: Floral structures, Sepals, Calyx\n**Prerequisites**: Basic knowledge of plant anatomy and floral parts.\n## SOLUTION PATHWAY\n**Given Information**:\n - The question asks about the modification of pappus.\n - The options are different floral parts.\n**Method & Steps**:\n 1. Recall the definition of pappus: Pappus is a modified calyx seen in some flowers, especially those of the Asteraceae family (e.g., sunflowers, dandelions).\n 2. Identify the correct floral part: Since pappus is a modified calyx, the correct answer is calyx.\n**Result**: Calyx\n**Verification**: Basic understanding of plant structures.\n## OPTION ANALYSIS\n[A] ✓: **Calyx** is the correct answer as pappus is a modified form of the calyx.\n[B] :x: **Corolla** refers to the petals of a flower, which are distinct from the calyx.\n[C] :x: **Bract** is a modified leaf associated with a flower or inflorescence, not related to pappus.\n[D] :x: **Gynoecium** is the female reproductive part of the flower, unrelated to pappus.\n## LEARNING AIDS\n**Common Mistakes**:\n1. Confusing different floral parts: Review the basic structures of a flower and their functions.\n2. Assuming pappus is a unique structure: Remember that it is a modification of the calyx.\n**Quick Tips**:\n1. Associate pappus with dandelion and other similar flowers to remember its origin from calyx.\n2. Use diagrams to memorize floral structures.

## CORE INFORMATION\n✓ **Answer**: A\n## CONCEPT FRAMEWORK\n\t**Primary Concept**: Plant Morphology\n\t**Related Topics**: Floral Structures, Calyx, Corolla, Bract, Gynoecium\n\t**Prerequisites**: Basic knowledge of plant anatomy and flower structures.\n## SOLUTION PATHWAY\n**Given Information**:\n\tThe question asks which floral part is modified into a pappus.\n**Method & Steps**:\n\t1. Recall the definition of a pappus. A pappus is a modified calyx structure often seen in the Asteraceae family (e.g., sunflowers, dandelions).\n\t2. Identify the floral part that corresponds to the definition of pappus.\n\t3. The calyx is the whorl of sepals, and in some cases, these sepals are modified into bristle-like structures forming the pappus.\n\t4. Select the correct option.\n\t**Result**: The correct answer is Calyx\n ## OPTION ANALYSIS\n[A] ✓: Calyx is the correct answer because it is the modified floral part that forms the pappus.\n[B] :x: Corolla is the whorl of petals and is not modified into a pappus.\n[C] :x: Bracts are modified leaves associated with flowers and are not the structure forming the pappus.\n[D] :x: Gynoecium is the female reproductive part of the flower and is not modified to form the pappus.\n ## LEARNING AIDS\n\t**Common Mistakes**:\n\t\t1.[Error 1]: Confusing pappus with other floral parts. [How to avoid]: Review the function and appearance of each floral part.\n\t**Quick Tips**:\n\t\t1.[Helpful shortcut]: Remember the key role of the calyx as the outer whorl of the flower and that it is often modified in various ways.\n\t\t2.[Memory aid]: Think of dandelions; the feathery structure that helps them disperse is the modified calyx (pappus).