CAIE Biology (9700)

L1 is a slide of a stained transverse section through a plant organ.

(i) Draw a large plan diagram of a region of the organ on L1 to include the epidermis and two vascular bundles. Use a sharp pencil. Use one ruled label line and label to identify the phloem.

Observe the xylem on the section of the plant organ on L1. Select a line of four adjacent xylem vessel elements. Each xylem vessel element must touch at least one of the other xylem vessel elements.

Fig. 2.1 is a diagram of a stage micrometer scale that is being used to calibrate an eyepiece graticule. One division, on either the stage micrometer scale or the eyepiece graticule, is the distance between two adjacent lines. The length of one division on this stage micrometer is 0.1 mm. stage micrometer eyepiece graticule

Use Fig. 2.1 to calculate the actual length of one eyepiece graticule unit. Show your working and give your answer in micrometres (µm). actual length = µm [2] Fig. 2.2 is a photomicrograph of a stained transverse section of the same plant organ as the section on L1 but from a different plant. This was taken using the same microscope and eyepiece graticule as in Fig. 2.1. The eyepiece graticule scale has been placed across one of the larger sections of vascular tissue, labelled T in Fig. 2.2.

Use the calibration of the eyepiece graticule unit from (b)(i) to calculate the actual length of the section of vascular tissue T in Fig. 2.2. Show your working and use appropriate units. actual length of the vascular tissue T =

Fig. 2.3 is the same photomicrograph as that shown in Fig. 2.2.

Identify three observable differences, other than colour, between the section on L1 and the section in Fig. 2.3. Record these three observable differences in Table 2.1. Table 2.1 feature L1 Fig. 2.3

Identify the plant organ on L1 and in Fig. 2.3. State how one observable feature helped you to identify the plant organ. plant organ [1] [Total: 18] reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge.