Stomata
Singular: stoma
These are holes or openings in the leaves that enable transpiration to occur. In addition to water vapour, other gases in the air also move in and out the leaves through stomata. Examples of the gases are oxygen and carbon dioxide which diffuse in and out during the processes of respiration and photosynthesis.
When the guard cells are turgid, the stoma opens bigger. When the guard cells are flaccid, the stoma becomes smaller.
More stomata are found on the bottom surface of the leaves.
Liang-liang stoma
Stoma merupakan liang-liang pada daun yang membolehkan transpirasi berlaku. Selain daripada wap air, gas-gas udara lain juga bergerak masuk dan keluar stoma. Contoh-contoh gas yang berbaur melalui stoma ialah oksigen dan karbon dioksida yang digunakan untuk proses respirasi dan proses fotosintesis. Dua sel dinding mengawal saiz liang stoma. Apabila sel-sel ini cekang, liang stoma membesar. Apabila sel-sel ini menjadi lembik, liang stoma mengecil.
Lebih banyak liang-liang stoma terdapat pada permukaan bawah daun.
Quiz
What is transpiration?
Click here to find out more.
Apakah transpirasi?
Klik di sini.