Botana curus is a valuable plant because it produces Curol, a compound used for treating certain kinds of cancer. Curol cannot be produced in the laboratory. Botana Curus grows very slowly and is on the endangered species list, so its ability to provide Curol in large quantities is limited. Species that are more closely related to Botana curus are more likely to produce the important substance Curol. Three similar plant species that are plentiful (X, Y, and Z) may be related to Botana curus. You will work as a researcher to: * Gather structural and molecular evidence to determine which plant species is most closely related to the hypothetical species. Botana curus. * Use this evidence to decide which plant species is most likely to serve as a source of the important substance Curol. Safety
* You will need to wear goggles while conducting Test 4 and 5. * Do not eat or drink anything in the laboratory while doing this laboratory activity. Important Note: Record all of your data and answer on these laboratory sheets. You will need to keep them for review before the Regents Examination. Later, you will need to transfer your answers to separate Student Answers Packet. Your teacher will use the packet in grading your work, and the school will retain it as evidence of your completion of the laboratory requirements for the Living Environment Regents Examination. Structural Evidence for Relationships
Perform the following test and record your observations in Table 1 on page 8 of this packet. Use a hand lens or microscope as needed. Test 1—Structural characteristics of plants
a. Do not remove the plant samples from the plastic bags/cards. b. Compare the structural characteristics of the lant samples. Record your observations in Table 1 (see page 8). Test 2---Structural Characteristics of seeds
a. Do not remove the seed samples from the plastic bags/cards. b. Compare the structural characteristics of the seed samples. Record your observations in Table 1 Test 3---Microscopic Internal Structure of stems.
a. Use the lowest magnification on your microscope to examine the slides that show cross sections through stems of Botana curus and Species X, Y, and Z. Compare the arrangement (circular or scattered) of the bundles of conducting tissue in the speciments. Refer to figure 1.
b. Record your observations (using words and /or diagrams) of the conducting tissue arrangements in Table 1. Hypothesize: Test 1-3
a. Based on your data for structural relationships, which species (X, Y, or Z) would you hypothesize is most likely to produce Curol? b. Explain how the evidence from your data table supports your hypothesis. You wil test your hypothesis by completing additional test in the second part of this laboratory activity. Molecular Evidence for Relationships
Test 4---Paper Chromatography to Separate Plant Pigments
a. You must wear safety goggles when performing this part of the activity. b. Draw a pencil line 2cm from the bottom of the chromatography paper Bc (Botana curus), X, Y, and Z as shown in figure 1. c. Use a clean microtip dropper to transfer two drops of plant extract from Botana curus just above the pencil line as shown in Figure 1.
d. Using a clean dropper each time, repeat the procedure to place drops of the other plant extracts in the appropriated locations on the paper. e. Add just enough water to cover the bottom of the cup approximately 1 cm deep. The water line should NOT be high enough to touch the spots of plant extract on the chromatography paper when the paper is placed in the cup. f. Fold the chromatography paper and stand it in the cup as shown in Figure 2. g. The chromatography paper must be removed from the cup before the water line reaches the pencil labels at the top of the chromatography paper. While the plant extracts are moving up the chromatography paper, go on to test 5, but keep checking on the...