A-Level Biology - A-Level Biology - Xylem & Phloem - Structure | Function | Distribution (2026/27 exams)

⭐️ Check out our website https://www.cognito.org/ ⭐️ *** WHAT'S COVERED *** 1. Why plants need transport systems * The limitations of diffusion in multicellular organisms * Surface area to volume ratio considerations 2. Structure and function of xylem * Transport of water and mineral ions * Adaptations of xylem vessels including lignified walls and pits 3. Structure and function of phloem * Transport of assimilates like sugars and amino acids * Adaptations of sieve tube elements and companion cells * The role of plasmodesmata and mitochondria 4. Distribution of transport tissues * Arrangement of vascular bundles in roots, stems and leaves *** EXAM BOARD SPECIFIC INFO *** AQA - You don't need to know about the distribution of xylem and phloem tissues in different parts of the plant OCR - Everything is relevant to your course! CIE - Everything is relevant to your course! *** CHAPTERS *** 0:26 Why plants need transport systems 1:11 Structure and function of xylem 2:23 Structure and function of phloem 3:50 Distribution of tissues in roots 4:19 Distribution of tissues in stems 4:47 Distribution of tissues in leaves *** PLAYLISTS *** https://youtube.com/playlist?list=PLidqqIGKox7VzYfPIVt8T09xOLNcolCe4&si=8JmDajxjtba6rdc3 https://youtube.com/playlist?list=PLidqqIGKox7UZ3mWhbHv2aA_1vnbsfRPq&si=q3hEKdA4v7kbfwMe https://youtube.com/playlist?list=PLidqqIGKox7UTimdJ3eFcnt6xL9GUt2a6 https://youtube.com/playlist?list=PLidqqIGKox7XPh1QacLRiKto_UlnRIEVh&si=orIUwL3o2jOoiYjT https://youtube.com/playlist?list=PLidqqIGKox7X5UFT-expKIuR-i-BN3Q1g&si=DcihOwUkd9oWbbdp https://youtube.com/playlist?list=PLidqqIGKox7WeOKVGHxcd69kKqtwrKl8W&si=Y8MsO-FK948jnxpS https://youtube.com/playlist?list=PLidqqIGKox7UVC-8WC9djoeBzwxPeXph7&si=-7i5Iq7yOeJrhtu6 https://youtube.com/playlist?list=PLidqqIGKox7VKJD2WxRhoKaI6JGLVean8&si=NH_Q1ujhVgACM2FU #Alevel #Biology #study #revision #school #exam #AQA #OCR #Edexcel