Botany 101 Lab ManualTacoma Community CollegeBiology Laboratory: Safety, Procedures, Emergencies

1. No open food or drink is permitted in the lab at any time, whether a lab is in progress or not. No eating, drinking, chewing of gum or tobacco is permitted. Never taste anything at all while in the lab rooms.

1. Know the locations of the eye wash and shower stations, fire alarm, fire extinguisher, first aid kit, and emergency exits.

1. Safety instructions are given at the beginning of each lab period. Always arrive on time so that you know what you are supposed to do and are informed of any specific safety concerns or safety equipment associated with the days lab activity.

1. Wear any required personal protective equipment (lab coat, apron, goggles, etc).

1. Stash book bags safely so that they wont trip people.

1. Report all illnesses, injuries, breakages, or spills to your laboratory instructor immediately.

1. Clean broken glass (glass that is not contaminated with any chemical reagents, blood, or bacteria) can be swept up using the dust pan and placed in the broken glass container. If the glass is contaminated in any way, keep the area clear to prevent tripping or laceration hazards, and consult your instructor for proper disposal guidance. A broken glass flow-chart is available in the lab to help you decide what to do.

1. Notify your instructor if any of the equipment is faulty.

1. Clean up your entire work area before leaving. Put away all equipment and supplies in their original places. Disinfect your work surface if the lab activity involved any infectious materials.

1. Use the appropriate waste containers provided for any infectious or hazardous materials used in lab.

1. Safety information about hazardous chemicals used in the lab activities can be found in the Material Safety Data Sheets (MSDS), located in the Right-to-Know Binder in the safety station. We (faculty and students) should be fully aware of the properties of the chemicals we are using. Please use the MSDSs. If you cannot find the MSDS for the reagent you are using in lab, inform your instructor. They are also relatively easy to find online. A keyword example is Sodium Chloride MSDS.

1. Use caution with the lab chairs. Because they are on casters, the can roll away when you are standing at your workstation. Make sure your chair is where you expect it to be before sitting down. Do not use your chair as a means of moving from one part of the lab to the other.

1. Wash your hands before leaving the lab room.

Laboratory 1: Pea Lab - Principles of the Scientific Method

Adapted by permission from Steve Brumbaugh from the Green River Biology Lab Manual

Exercise: Applying the Scientific Method

The work required for this lab spans about four weeks depending on a number of factors. Your instructor will explain the methods of storage for your experimental set-ups, and how to arrange for the use of the rooms and greenhouse to do your work.

Pre-lab Assignment

Before coming to lab carefully read the sections of your textbook regarding the scientific method and the pages of this exercise then answer the pre-lab questions.

Goals of this Lab Exercise

To understand the mechanisms used in the scientific method

Design an experiment and carry out the steps of a scientific experiment

To work cooperatively in establishing a protocol for a scientific experiment

Introduction

In its simplest form, an experiment involves a check or control group compared with an experimental or test group. The control is held under constant conditions while the test group is exposed to the affects of various factors, one at a time. Any changes that occur in the test group, but not in the control group, are assumed to be the result of the condition that is changed. Each treatment, including the control, should be replicated, and the replicate organisms should be carefully distributed so that no individuals being treated will be favored more than others. In the activity that follows, you will design your own original experiment.

Materials (per group of four students)

20 Little Marvel pea seeds and 2 flower pots

Atomizer containing gibberellic acid solution

Growth medium (vermiculite in greenhouse)

Atomizer of de-ionized water

Procedure

Each team should decide on its organization, discuss the problem/hypothesis, and plan the experiment. Gather the materials needed and begin the activity. Prepare your seeds planting by following the following method.

1. Seed Preparation - Place 20 pea seeds in a beaker and cover them with tap water so that the water level is about 2 cm above the level of the pea seeds. Label the beaker with team identification and date. Place it in a dark cupboard in the biology lab and let the pea seeds soak overnight (i.e. 12-24 hours). The soaked seeds should now be planted as directed below.

2. After the seeds have soaked overnight take them to the greenhouse. Prepare 4 flowerpots by adding moistened soil to each. The containers should be about 3/4 full. In each pot, place 6 soaked seeds. Cover the seeds with another inch of moistened soil. Label each pot with team identification and date and keep them in the greenhouse. Keep the medium moist, but not soggy wet.

3. When the seedlings are 2-3 cm high measure their height in millimeters. This is done by measuring the distance from the growth medium surface to the tip of the shoot apex. Measure each seedling and record your data. These lengths are the initial measurements. You will now apply your experimental treatment to your experimental group. First you need to decide what your experimental treatment will be! You can use one of the following suggestions, or come up with your own. If you use your own, please check your ideas with your instructor.

a. Spray plants with gibberrelic acid, a growth hormone

b. Add a few fertilizer pellets

c. Grow your plants under blue or red light

d. Grow your plants in the shade

e. pinch your plants when they are about 4cm high (this means plucking off the uppermost leaves)

f. Grow your plants outside the greenhouse

4. On each day of class, measure & calculate the average number of leaves per plant, the average internode length, and the average height per treatment. Record your data on the data table in your in-lab report sheet.

Figure 1 Plant Anatomy This drawing is to be used to guide the measurement of the inter-node length.

Report SheetName .

Pea Lab ExerciseGroup Names .

.

.

.

Table1: Average internode length, number of leaves per plant, and height for the pea plant experiment

Date

Ave. internode length (cm)

Ave. # of leaves per plant

Average height (cm)

Observations

Experimental Group

Control Group

Experimental Group

Control Group

Experimental Group

Control Group

Experimental Group

Control Group

Experimental Group

Control Group

Experimental Group

Control Group

1. Prepare a graph of the average daily heights for both the experimental and control groups. Properly title and label your graph (Appendix A). Graph both sets of data on the same graph by using different colors and a key. Attach this graph to your lab. In the space below, explain the results and trends seen in your graph:

2. Prepare a graph of the average internode lengths for both the experimental and control groups. Properly title and label your graph (Appendix A). Graph both sets of data on the same graph by using different colors and a key. Attach this graph to your lab. In the space below, explain the results and trends seen in your graph:

3. Prepare a graph of the average number of leaves for both the experimental and control groups. Properly title and label your graph (Appendix A). Graph both sets of data on the same graph by using different colors and a key. Attach this graph to your lab. In the space below, explain the results and trends seen in your graph:

4. What correlation(s) did you observe between number of leaves, internode length, and plant height?

5. List at least two observations of similarities and/or differences in the general growth of the experimental and control plants other than the observations recorded in question 4 above.

6. List at least three possible sources of error that may have influenced the data you collected.

7. Suggest 3 ways to provide more valid data or show other pertinent results. Be specific!!!

8. Did you confirm your hypothesis? YES / NO (Circle One)

Pre-Lab Report Sheet

Pea Lab Exercise

Name_________________________________

Note:

Answer the following six questions before coming to lab, but after having read the previous pages of this handout!

1. Write a hypothesis using the "If .... Then" format for this experiment.

2. What is the independent variable for your pea experiment?

3. What is the dependent variable(s) for your pea experiment?

4. Name at least three controlled variables in the pea experiment?

5. Give a brief explanation of your experimental design:

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Laboratory 2: Microscopy

Parts of the Swift M5 Microscope

(HeadpieceOcular lens (10X)