🎯 What You'll Learn🎯 Objektif Pembelajaran
Describe the structure and function of xylem tissueMenerangkan struktur dan fungsi tisu xilem
Explain how water moves through plants via transpiration pullMenerangkan bagaimana air bergerak melalui tumbuhan melalui tarikan transpirasi
Describe the structure and function of phloem tissueMenerangkan struktur dan fungsi tisu floem
Explain translocation of sucrose and amino acidsMenerangkan translokasi sukrosa dan asid amino
Discuss factors affecting transpiration rateMembincangkan faktor yang mempengaruhi kadar transpirasi
🌊 Transport in Plants | Pengangkutan dalam Tumbuhan🌊 Pengangkutan dalam Tumbuhan
Xylem: Water and Mineral TransportXilem: Pengangkutan Air dan Mineral
Transports water and dissolved minerals from roots to leaves.Mengangkut air dan mineral terlarut dari akar ke daun.
Pathway:Laluan: Root hair → Cortex → Endodermis → Xylem → LeavesRambut akar → Korteks → Endodermis → Xilem → Daun
| MechanismMekanisme | DescriptionKeterangan |
|---|---|
| Root PressureTekanan Akar | Active transport pushes water up from rootsPengangkutan aktif menolak air naik dari akar |
| Capillary ActionTindakan Kapilari | Adhesion and cohesion in narrow xylem vesselsAdhesi dan kohesi dalam salur xilem sempit |
| Transpiration PullTarikan Transpirasi | Cohesion-tension theory: Water pulled up by evaporationTeori kohesi-tegangan: Air ditarik naik melalui penyejatan |
Phloem: Food TransportFloem: Pengangkutan Makanan
Translocates sucrose and amino acids from source to sink.Mentranslokasi sukrosa dan asid amino dari sumber ke sink.
Source:Sumber: Leaves (photosynthesis) → Daun (fotosintesis) → Sink:Sink: Roots, growing points, storage organsAkar, titik pertumbuhan, organ simpanan
| AspectCiri | DetailKeterangan |
|---|---|
| MechanismMekanisme | Pressure flow hypothesis (Mass flow hypothesis by Münch)Hipotesis aliran tekanan (Hipotesis aliran jisim oleh Münch) |
| DirectionArah | Bidirectional (up or down depending on plant needs)Dua hala (atas atau bawah bergantung kepada keperluan tumbuhan) |
| ContentsKandungan | Sucrose, amino acids, hormonesSukrosa, asid amino, hormon |
• "Xylem = X marks the spot UP" – Water goes upAir naik
• "Phloem = Flow = Goes both ways" – Food flows anywhereMakanan mengalir ke mana-mana
• "Transpiration Pull = Tension" – Cohesion-tension pulls waterKohesi-tegangan menarik air
💧 Transpiration and Its Factors💧 Transpirasi dan Faktornya
Transpiration is water loss through stomata, creating the pull for water transport.Transpirasi ialah kehilangan air melalui stoma, mewujudkan tarikan untuk pengangkutan air.
| FactorFaktor | Effect on TranspirationKesan terhadap Transpirasi |
|---|---|
| HumidityKelembapan | High humidity ↓ transpiration (less water potential difference)Kelembapan tinggi ↓ transpirasi (beza keupayaan air kurang) |
| TemperatureSuhu | Higher temperature ↑ transpiration (faster evaporation)Suhu tinggi ↑ transpirasi (penyejatan lebih cepat) |
| Wind SpeedKelajuan Angin | Higher wind ↑ transpiration (removes humid air)Angin kuat ↑ transpirasi (menyingkirkan udara lembap) |
| Light IntensityKeamatan Cahaya | Bright light ↑ transpiration (stomata open)Cahaya terang ↑ transpirasi (stoma terbuka) |
🌿 Plant Transport Systems🌿 Sistem Pengangkutan Tumbuhan
Comparison of xylem and phloem functions.Perbandingan fungsi xilem dan floem.
| FeatureCiri | XylemXilem | PhloemFloem |
|---|---|---|
| DirectionArah | Unidirectional (up)Satu hala (atas) | BidirectionalDua hala |
| TransportPengangkutan | Water + mineralsAir + mineral | Sucrose + amino acidsSukrosa + asid amino |
| MechanismMekanisme | Passive (transpiration pull)Pasif (tarikan transpirasi) | Active (pressure flow)Aktif (aliran tekanan) |
| CellsSel | Tracheids, vessel elements (dead)Trakeid, elemen salur (mati) | Sieve tubes, companion cells (living)Tiub tapis, sel pengiring (hidup) |
💯 Quick Check💯 Semakan Cepat
What is the main driving force for water transport in tall trees?Apakah daya utama pengangkutan air dalam pokok tinggi?
🇲🇾 Malaysian InnovationInovasi Malaysia
🌳 Meranti trees:Pokok Meranti: Tall rainforest trees rely on efficient xylem transport to reach canopy heights over 80m.Pokok hutan hujan tinggi bergantung pada pengangkutan xilem yang cekap untuk mencapai kanopi melebihi 80m.
💧 Water transport:Pengangkutan air: In humid Malaysian climate, transpiration pull is crucial for nutrient delivery to leaves.Dalam iklim lembap Malaysia, tarikan transpirasi penting untuk penghantaran nutrien ke daun.
🌾 Rice paddies:Sawah padi: Flooded fields affect root oxygen, influencing transport efficiency.Sawah yang ditenggelami mempengaruhi oksigen akar, mempengaruhi kecekapan pengangkutan.
SPM 2022 Paper 2SPM 2022 Kertas 2
The diagram shows a cross-section of a plant stem.Rajah menunjukkan rentas keratan batang tumbuhan.
(a) Label the xylem and phloem. [2 marks]Labelkan xilem dan floem. [2 markah]
(b) Describe the pathway of water from soil to leaf. [3 marks]Terangkan laluan air dari tanah ke daun. [3 markah]
(c) Explain why tall trees can transport water against gravity. [2 marks]Terangkan mengapa pokok tinggi boleh mengangkut air melawan graviti. [2 markah]