Page 70 - Hybrid PBD 2022 Tg 5 - Biology

Biologi Tingkatan 5 Bab 2

Kertas 2

Bahagian A

1. Rajah 1 menunjukkan keratan rentas sehelai daun.
Diagram 1 shows a cross section of a leaf.
P

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Q
Rajah 1 / Diagram 1
(a) Namakan struktur berlabel P dan Q. / Name the structure labelled P and Q.
P: Kutikel / Cuticle Q: Stoma / Stoma
[2 markah / 2 marks]
(b) Apakah kepentingan struktur P kepada daun? / What is the importance of structure P to the leaf?
– Lapisan berlilin dan kalis air supaya dapat menghalang kehilangan air berlebihan melalui penyejatan
Waxy layer and waterproof to prevent the excessive loss of water through evaporation
– Lapisan lutsinar supaya membenarkan cahaya matahari menembusi ke dalam daun
Transparent layer to allow the sunlight to penetrate into the leaf

– Menghalang kemasukan mikroorganisma atau patogen ke dalam daun
Prevent the entry of microorganism or pathogen into the leaf
[2 markah / 2 marks]
(c) Struktur Q memainkan peranan yang penting dalam proses transpirasi. Jelaskan bagaimana pergerakan
udara mempengaruhi kadar transpirasi suatu tumbuhan.
Structure Q plays important role in transpiration process. Explain how air movements affect the rate of transpiration of a plant.
– Pada kelajuan udara yang rendah (perlahan), kadar transpirasi rendah
At low air movement (slow), the rate of transpiration is low
– Semakin laju pergerakan udara, semakin tinggi kadar transpirasi

The higher the air movement, the higher the rate of transpiration
– Kerana pergerakan udara menyebabkan wap air yang berkumpul di Q (stoma) ditiup ke tempat lain

Because the air movement causes the water vapour around Q (stoma) to blow away
– Menyebabkan kelembapan udara di sekitar Q (stoma) menurun
Causing the air humidity around Q (stoma) to decrease
– Maka, lebih banyak molekul air akan tersejat keluar daripada Q (stoma)

Thus, more water molecules will evaporate out from the Q (stomata)
[3 markah / 3 marks]

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02 HYBRID PBD BIOLOGY TG5.indd 45 18/11/2021 11:05 AM