K1 is a slide of a stained transverse section through a plant stem. You are not expected to be familiar with this specimen.

1. (a)(i)Observe all the different tissues in the stem on K1 and select an area (sector) that shows the epidermis and vascular bundles. Use a sharp pencil for drawings. Draw a large plan diagram of the sector you have selected on K1 to include: • the epidermis • one outer vascular bundle • three inner vascular bundles (touching each other) • any other observable tissues. Use one ruled label line and label to identify the cortex. You are expected to draw the correct shape and proportions of the different tissues. [5][5]
2. (a)(ii)Observe the cells around the air spaces on K1. Select one group of four adjacent, touching cells along the side of an air space. Each cell must touch at least one of the other cells. Use the eyepiece graticule in the microscope to measure, as shown in Fig. 2.1: • the total length of the four cells, L • the depth of one of the cells, D. [Figure 2.1] L .................................................. eyepiece graticule units D .................................................. eyepiece graticule units [1][1]
3. (a)(iii)Use the measurements from (a)(ii) to help you make a large drawing of this group of four cells on K1. Use one ruled label line and label to identify the cell wall of one cell. [5][5]
4. (a)(iv)The tissues on K1 include air spaces. Suggest a habitat where K1 might grow. ...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................[1][1]
5. (b)Fig. 2.2 is a photomicrograph of a stained transverse section through part of the stem of a different plant species. You are not expected to be familiar with this specimen. [Figure 2.2] A student calibrated the eyepiece graticule in a light microscope using a stage micrometer scale so that the actual width of the stem could be found. The calibration was one eyepiece graticule division equal to 29.5 µm. Fig. 2.2 shows a photomicrograph taken using the same microscope with the same lenses as the student. Use the calibration of the eyepiece graticule division and Fig. 2.2 to calculate the actual width of the stem, shown by line X-Y. Show all the steps in your working and use appropriate units. actual width of the stem = ..................................................................... [3][3]
6. (c)Fig. 2.3 is the same photomicrograph without the eyepiece graticule scale and without the line X-Y. [Figure 2.3] Annotate Fig. 2.3 to describe three observable differences between the stem sections in Fig. 2.3 and on K1 by: • drawing label lines to three features in Fig. 2.3 that show these differences • describing next to each line how each feature is different from the specimen on K1. [3][3]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.