Appu focused a section of leaf under the microscope and observed the following image. Statements below list characteristics of the labeled parts. Based on the statements choose the correct option.
Statement 1-(iii) helps to regulate transpiration.
Statement 2-(ii) allows only entry of water vapour.
Statement 3-(i) is essential for photosynthesis.
Statement 4-(iii) closes completely in the morning.
Statements 1 and 3 are correct.
The labelled parts are chloroplast (i), stomata (ii) and guard cells (iii) respectively. A chloroplast is the cell organelle present in plant cells and contains chlorophyll as a pigment. Chlorophyll is the green pigment which traps solar energy and is one of the major requisite for photosynthesis. Stomata are tiny pores on the surface of the leaf which allow the exchange of gases and water vapour. Surrounding each stoma are two guard cells, which regulate the opening and closing of the stoma to facilitate gaseous exchange and control transpiration in plants. Guard cells are able to control the opening of stomata by changing shape. They are like an inflatable set of doors that make the opening between the two cells wider or narrower.