This problem set is the definitive learning material designed to cultivate the "solid foundational knowledge" and "practical application skills" necessary to pass the selection exam, covering everything from the latest APG classification system to tree physiology, anatomy, and diagnostic practices through 300 carefully selected questions. • For those who aim to pass the selection exam, the first step to becoming a Tree Doctor, on their first attempt and aspire to become specialists in green diagnosis and treatment. • For those who want to perfectly organize plant classification based on the latest APG classification system (molecular phylogenetics) through practice exercises. • For those who want to deeply understand the physiology of tree growth and substance transport, such as the mechanisms of "xylem (vessels and tracheids)" and "cambium." • For those who want to overcome weak areas and maximize their score on the actual exam through the abundant volume of 300 questions and detailed explanations. ◾️ Problem Set Overview This book consists of a total of 300 questions, covering the following main areas, in line with the exam trends for the selection test. • Problem Composition: 300 questions in total (sectional practice + answer/explanation section) • Main Content Included: • Plant Classification and Tree Species Identification (Questions 1~): • Characteristics of the APG classification system (classification based on DNA analysis) and changes from previous systems (e.g., Engler system). • Distinction between angiosperms and gymnosperms, and classification of major tree species such as cherry (Rosaceae) and cedar (Cupressaceae). • Tree Morphology and Structure: • Leaf morphology (simple/compound leaves, phyllotaxy), flower structure (perfect/imperfect flowers), fruit classification (berries, dry fruits). • Wood Structure Analysis: Identification of ring-porous, diffuse-porous, and semi-ring-porous woods and representative tree species (e.g., Zelkova, cherry, oaks). • Tree Physiology and Growth (Questions 26~): • Mechanism of secondary growth by cambium and the functions of xylem (water/nutrient transport) and phloem (photosynthate transport). • Differences in properties between sapwood and heartwood, and the process of annual ring formation through earlywood and latewood. • Practical Exercises and Exam Preparation: • Question composition at the same level as the actual exam, primarily in a five-choice multiple-choice format. • Explanations based on the latest knowledge reflecting the exam trends for fiscal year 2025.