Chapter 23 Name______
Name ______
Lab Title: Microscopic Examination of Plants Date______
Lab Station # ______
Score____/_____
Please read through this lab competely before beginning!
All of the materials for this lab will be used by 7 sections of biology students over the next two days. Please treat them carefully: when you finish, return all six slides to their colored plastic case at your lab station, and place all fresh plant material back in the petri plates or bottles. DO NOT THROW OUT ANY OF THE FRESH PLANT MATERIAL. Failure follow these directions will result in point deductions.
For this 2 part lab, you will be examining plants that are dried/prepared slides of plants using the compound light microscopes, as well as fresh (1 week old germinating corn and beans) using a dissecting microscope. For both fresh and dried materials, you will examine three organs (leaves, stems, roots), of both monocot and dicot samples.
You will each be doing your own 6 drawings for Part I, Dried Plant Organs, and do the 3-section lab write-up as a pair - details specified on the attached sheets. For Part II, Fresh Plant Organs, you will do the 3-section lab write-up as a pair.
Neatness and detail count!
What you turn in:
1. Each pair will submit one report, which will include a set of 6 colored drawings per student, and one copy of the write-up of each Part I and Part II, per pair of students. The write-up may be handwritten or typed.
2. Staple and submit this handout on top of your drawings and write-up.
Part I
Dried Plant Organs –use compound light microscopes
(prepared slides)
1. MATERIALS & PROCEDURE – this section should be 1 paragraph. Write out what you are using/doing in paragraph or bulleted format. Your materials include everything you use. Your procedure includes everything you do. Each group will be given a box containing 6 slides. There will be monocot and dicot plants, and 3 organs of each. You will be using the compound light microscopes (max.mag. is 400x).
a. . Information on how the sample was sliced is in small letters on the slide label- see below:
c.s. (cross-section like a slice)
l.s. (longitudinal section, length-wise slice)
PLEASE NOTE: EACH GROUP MAY HAVE DIFFERENT SLIDES- IT IS IMPORTANT THAT YOUR DRAWINGS ARE LABELED WITH EXACTLY WHAT SLIDES YOU USED-choices below:
Moncots: Corn (Zea), Elodea, Lilium, Poa, any grass
Dicots: Begonia, Ficus, Nerium, Ranunculus, Syringa, Tilia, Verbascum
THREE TYPES OF PLANT ORGANS-leaves, stems, and roots
3. DRAWINGS – You will be given plain paper for your colored drawings.
You will be doing a total of 6 drawings with colored pencils. Use a circle template provided, to draw 3 drawings on one side, and the 3 on the other. You may make your drawings at either the medium (100x) OR high (400x) total magnification. Look around the sample, to see the different tissue types.
Each drawing should include:
* Title (species/organ type- and either c.s. or l.s.)
* Labels of structures that you recognize (ex: cell walls, root hairs, chloroplasts, stomata).
* Label of tissues you recognize (i.e. vascular, epidermis, ground)-you may not see all 3)
* Total magnification used
4. DISCUSSION/CONCLUSIONS –this section should be 3 paragraphs- one addressing monocots, one for the dicots, and one that include comparisons of your observations between the monocots and dicots and the 3 organ types. This third paragraph may be a Venn diagram if you choose. Make concluding statements.
Part II
Fresh Plant Organs - use dissecting microscopes (larger scope,lower mag)
(wet plants in Petri plates and bottles)
BACKGROUND
You will be looking at fresh plant material from 2 species- young (1 week old) germinating corn (monocot) and bean (dicot) seeds, by using dissecting microscopes. Dissecting scopes use a low magnification, and are intended to observe larger objects that do not need to be flat or under a coverslip; you can move the sample by hand as you observe it. As you examine the material, you will write several observations on what you see. You will be focusing on the external surfaces of your samples. Your lab write-up will include materials and procedure, observations, and a discussion/conclusion.
1. (MATERIALS & PROCEDURE) –DO NOT THROW OUT ANY OF THE FRESH PLANT MATERIAL. RETURN IT TO THE PETRI DISH OR BOTTLE. This section should be 1 paragraph. Write out what you are using/doing in paragraph or numbered step format. You will be looking at the surface of the three plant organs (leaf/stem/root) of 2 species, using dissecting microscopes. SHARE YOUR SAMPLES WITH OTHER PAIRS AT YOUR TABLE.. You will be examining your samples as they ‘float’ in the Petri plate so that it does not dry out- you are NOT using slides and coverslips.
A. Monocot- corn/grass: leaf, stem, root
B. Dicot – bean/pea: leaf, stem, root
2. OBSERVATIONS– This may be in bullet or paragraph form. Specifically write down what plants it was you observed, from the choices above.
For the fresh plants, you are recording observations that mainly focus on the surface of the plants- these will include color/texture/size, etc.
5. DISCUSSION/CONCLUSIONS –This section should be 1 paragraph. Make statements that include comparisons of your observations between the 2 types of plants and the 3 organ types. Make 2 concluding statements.
.
CLEAN-UP- when you are finished, all materials must be returned neatly where you got them. Do not throw out any samples- just leave them in the Petri dishes for the next period, or else we may run out of material.