Botanical Explorations with the Dissecting Scope
Week 1, BIOL 2020L
The object of this assignment was to familiarize ourselves with the dissecting microscope and examine some sample specimens that we collected from outside. We gathered a Southern Wood Fern and a Monkey Puzzle Tree sample and took them into the lab. First we examined the fern and noticed tiny white hairs and circular spores all over the leaflets, which were not visible with the unaided eye.
Next, we observed the Monkey Puzzle Tree sample and noticed white striations on the leaves, which were not visible before. The leaves on the sample are pointed and arranged in a cone shape. Also, there are tiny, white drops or dots on each leaf of this plant.
- Josh and Brendin
Next, we observed the Monkey Puzzle Tree sample and noticed white striations on the leaves, which were not visible before. The leaves on the sample are pointed and arranged in a cone shape. Also, there are tiny, white drops or dots on each leaf of this plant.
- Josh and Brendin
Plant Cells and Scientific Drawings
Week 2, BIOL 2020L
Our objectives for this lab was to familiarize ourselves with the microscopes and practice making wet-mount slides for viewing. We practiced with several different species of plants which includes the Allium cepa, Elodea canadensis, Capsicum annuum, Tradescantia sp., Solanum tuberosum and the Musa sp.
We prepared the slides by taking thin samples from each plant and placing them on a clean slide. Then, we added water and a slide cover. After observing each slide in the microscope we then added dyes to see a contrast and highlight different features within the cells.
We learned that iodine highlights starch within the plant cells and colored them a dark-blue/purple tint. The Toluidine Blue O was another dye that we used and it highlighted lignin and other various items in each cell.
We prepared the slides by taking thin samples from each plant and placing them on a clean slide. Then, we added water and a slide cover. After observing each slide in the microscope we then added dyes to see a contrast and highlight different features within the cells.
We learned that iodine highlights starch within the plant cells and colored them a dark-blue/purple tint. The Toluidine Blue O was another dye that we used and it highlighted lignin and other various items in each cell.
As you can see in the photo of the A. cepa cells (left), the nuclei are pressed against the cell walls. This is so because of the enlarged vacuole that take up the majority of space within the cell. In the picture to the right it looks as if the nucleus is suspended within the cytoplasm but it is actually at the top or the bottom of the cell.
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Personally my favorite specimen was the A. cepa (onion). It was really amazing to take a sample and prepare a slide and be able to see things flowing through the cytoplasm.
- Josh |
"Tradescantia sp. was pretty awesome with how it has the built in defense mechanism to prevent animals from eating it. Its almost like the plant has a brain or it may just be a mutation from a long time ago!?"-Brendin
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Photosynthesis
Week 3, BIOL 2020L
In this lab we learned to use chromatography to separate and identify various pigments found in photosynthetic plant tissues. The pigments that we identified were chlorophyll a, chlorophyll b, xanthophyll and carotene. Also, we used a starch test to examine the effects that carbon-starvation and light-deprivation have on synthesis reactions of photosynthesis.
Plant Pigment
In this plant pigment test, we are identifying 4 key pigments found in plant cells. We will start by imprinting a line of tissue at the bottom of a thin strip of paper then placing it in a graduated cylinder with a few mLs of a 2:1 mixture of petroleum ether and methylene chloride. This mixture will travel up the paper bringing the plant pigments with it. Some pigments will travel further than the others and we should be able to identify which pigment is which based on color and location. These four pigments are chlorophyll a which should appear blue-green, chlorophyll b which should appear yellow-green, carotene which should appear bright yellow and xanthophyll which should be a pale yellow. From top to bottom we should see in this order carotene, xanthophyll, chlorophyll a then chlorophyll b.
![Picture](/uploads/3/8/1/7/38170739/1456873721.png)
Here you can see the separation of pigments on the sheet (shown here rotated 90˚ to the right so that left to right = bottom to top). The initial dark green mark is the sample from the leaf. Next to that (above) is a lighter green bell shape. This is indicating chlorophyll b. Above that mark is a faint green bell which indicates chlorophyll a. Above that is a more prominent greenish yellow bell which is displaying xanthophyll pigment and lastly is a straight yellow line showing carotene.
Light Test with Elodea
For this experiment we made a mixture of Phenol Red solution and water. We then blew air ( mostly CO2) out of our lungs into the solution which then turned orange from the carbon dioxide. We then evenly divided the solution into 4 test tubes. We placed Elodea in 2 into two of the tubes leaving the other 2 tubes as a control. We placed one control test tube and one with elodea under a high light source. We place the remaining 2 in our drawer and observed them after and hour.
As we expected, the test tubes that were exposed to light with the Elodea returned to its red color which indicated that photosynthesis had taken place. The test tubes that remained in the dark did not appear more red. The Elodea could not undergo photosynthesis.
Starch Test
This test was to see where in a plant photosynthesis is occurring.
Here you can see the sample of the leaf that we used for this experiment and the plant from which it came from. To the right are two pictures showing the water and ethanol baths we exposed the leaf sample to.
Here you can see the leaf (far left) after it has come out of the boiling water bath. Next to it is the leaf (left) after it has been removed from the ethanol bath and most of the pigment has been removed from the leaf. Notice the absence of the pink and green coloration towards the middle and ends of the leaf. Next is the leaf (right) soaking in an iodine bath to hopefully dye the starch that remains inside. Once the iodine is no longer being absorbed and is removed the leaf (far right) that remains has had its starch stained which is indicated by the dark coloring shown on the leaf. You can see that most, but not all, parts of the leaf are photosynthetic.
My favorite experiment in this lab was definitely separating the pigments found in a leaf sample. It was easy and the results were quick but no less interesting than any of the other experiments. You could observe visually the different pigments inching up the paper and separating right before your eyes. WOW!
- Josh |
Watching the pigments was slow but very interesting. It was science happening before our eyes. Science is happening all around us but not many people take it into perspective and thats why I enjoyed this experiment the most. -Brendin
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Simple & Complex Tissues
Week 4, BIOL 2020L
The purpose of this lab was to compare and contrast parenchyma, collenchyma, and sclerenchyma cells and tissues. We recognized three tissue systems of the plant body and identified water conducting cells of vascular tissue systems and relate their structural features with their functions. Lastly we described the characteristics of the epidermis. The three tissue systems are simple tissues, complex tissues, and ground tissues. Simple tissues are composed of cells that are of one type. Complex tissues are composed of cells that are of two or more types (xylem, phloem, and epidermis). Ground tissues are types of simple tissues like parenchyma, collenchyma, and sclerenchyma.
Sclerenchyma of an avocado fruit (Persea americana) dyed with phloroglucinol-HCl. The picture on the left shows a broader view at x100 magnification but on the right with the x400 magnification you can see more detail cellularly. Photos by Josh
This groups of four pictures are cross-sections of the wax plant (Hoya carnosa) which have all been stained for lignin detection. This is what you see colored red (top three) or blue (right). The samples that are red were stained with phloroglucinol-HCl; the sample that is blue was stained with TBO. You can see the contrast in detail between the x50 magnification (top-left), x100 magnification (top-middle) and x400 magnification (top-right). The other sample was stained using TBO just to get a comparison between the two stains. Photos by Josh
I would have to say that the phloroglucinol-HCl worked incredibly well and stains the cells beautifully. This was my most favorite experiment and observation because of the shear detail and beauty that can be seen under the microscope. -Josh |
GMO Investigations, part I
Week 5, BIOL 2020L
In this lab, we are extracting DNA from food samples and testing whether or not they are GMOs (genetically modified organisms). A genetically modified organism is any living organism whose genetic material has been artificially manipulated in a laboratory through genetic engineering, GE. During this lab we watched bits and pieces of a movie really explaining how large of an impact GMO's have on our society especially the farmers.
Preparing our samples for testing.
Splish splash its about to take a bath!
All of our different testing samples in the thermocycler machine. The purpose of the PCR machine is to multiply the amount of the DNA you're wanting to test. It does this by going through a cycle of temperatures. During these different temperatures they will denature or separate at 94 degrees Celsius the next temperate drops to 54 to begin annealing of the primers to the DNA, and then the temperature rises back to 72 which is the optimal temperature for the DNA polymerase function. This adds new nucleotides. This precoess is run 40 times during the cycle of the PCR.
"Gmo or No" will continue in next weeks lab after we visualize the products we get from running the gel electrophoresis!
GMO Investigations, part II
Week 6, BIOL 2020L
In this lab we will be running the results from last weeks PCR's in a 2% agarose gel through electrophoresis. We had to mix our PCR samples with a Orange G loading dye in order for us to be able to see the results. We then pipetted 20 micro liters of each sample into the gel also a PCR weight ruler which is used to measuring. We then ran the electrophoresis and put the gel in machine to run ultraviolet light on it so we were able to read what our results were.
Bryophytes & Ferns
Week 7, BIOL 2020L
In this lab we are observing several different types of bryophytes (non-vascular plants) and ferns (seed-free vascular plants). We are going to identify the different characteristics that distinguish these two groups from each other. For example, unlike nonvascular plants, vascular plants have specialized tissues responsible for transport of water and nutrients throughout the plant body.
Above are three different magnification on the same wholemount of living moss protonema. The moss protonema grows out of the germinating spores and then buds form off the protonema to grow outward into gametophytes. The circular shape in the far right picture (x400) you can see the bud coming out. Pictures by Josh Sumrall
Gametophytes and sporophytes of unidentified mosses. (Above two)
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Gametophytes and sporophytes of unidentified mosses. (Above two)
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My favorite part of this lab was going outside to the fern garden and looking for specimens that had sori, which are clusters of sporangia.
- Brendin |
My favorite part of the lab was when we placed our C-fern male gametophytes on the slide and watching them release the flagellated sperm.
-Josh |
Gymnosperms and Angiosperms
Week 8, BIOL 2020L
In this lab we are taking a look at various gymnosperms and angiosperms. Taking notice the varying characteristics of each type both in field samples and those in the lab. We will also identify parts of a flower, both sexual parts, those present and absent and the different variables that may occur in different types of plants.
Simple illustration of the parts of a flower. Notice first at the bottom are the sepals. These green, leafy parts are covering the flower before bloom. They protect the sex organs until it is time for pollination. Next you will see the female parts starting with the ovary, which houses all the components that will later become the seed (after germination). It is connected to the style (sperm pathway) and then the stigma (point of pollen contact). Next to it are the male parts. The anther (produces pollen) and filament (connects the anther to base of flower) make up the stamen. Lastly, in the background, are the petals which simply attract pollinators to the plant. - Drawing by Josh
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Above you can see images of female cones (Pinus sp.). Notice, in the image to the far left, the grooves in the woody parts of the cone. This is where the ovules were located. They develop into seeds after fertilization. The middle two images are longitudinal sections of mature embryos of a pine. These are what is formed within the cones.
These images (above) show the inside of an immature cone and the ovules that are not quite ready for reproduction.
These are images (above) of a cone that has been fertilized and its cones are ripened and ready to grow into a mature plant.
Above are pictures of a mature Gingko tree (Gingko biloba). The Gingko tree loses all of its leaves in one fell swoop every year before winter. This tree has just begun to grow its leaves back.
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The Juniper tree (Junipers sp.) pictured in the two images below and above (far right) are dioecious. Some trees have male parts and other trees have female parts. Shown above (far right) is a female tree.
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The next group of images are going to show the dissection of a common flower and will detail the sexual parts and how they operate.
The flower being dissected is said to be perfect. That is, it possesses both male and female organs on one flower. It has the ability to self pollinate but it hopes that cross pollination will occur because it will provide diversity for the plant and improve its fitness over time. Let's see what we can find! |
In each ovary, are areas (usually 3) that contain many ovules. These ovules are what gets fertilized when the sperm (transported by pollen) tunnels down the style and makes its way to the site of fertilization. Fertilization is a 1:1 mechanism. This means only one sperm is need to fertilize each ovule. Often times, thousands more pollen-containing-sperm are dispersed to increase the probability that each ovule will be fertilized. It is not guaranteed that each pollen will make it to a stigma!
"My favorite part was definitely dissecting the flower and observing all of the different parts within. It was very cool to get down deep and take something from nature rather than just being provided samples in the lab. It makes things more real by putting it into perspective." -Josh
All photos provided by Josh
"My favorite part was definitely dissecting the flower and observing all of the different parts within. It was very cool to get down deep and take something from nature rather than just being provided samples in the lab. It makes things more real by putting it into perspective." -Josh
All photos provided by Josh
Roots
Week 9, BIOL 2020L
In this lab we are focusing on roots, which is the portion of vascular of plants that grows underground. We will be looking at the different types of stems and shoots and roots that grow underneath the plant. Also, we will identify tissues of roots and root parts like primary tissue, primary meristems, and apical meristem.
ABOVE PHOTOS (3)
(Left) You can see sprouts from a pea plant (Pisum sativum) and its developing root system. (Right) Also pictured, is a maize plant (Zea mays) and its stages of development.
**Maize photo provided by Shutterstock®, other photos by Josh and Brendin
(Left) You can see sprouts from a pea plant (Pisum sativum) and its developing root system. (Right) Also pictured, is a maize plant (Zea mays) and its stages of development.
**Maize photo provided by Shutterstock®, other photos by Josh and Brendin
ABOVE PHOTOS (4)
C-fern roots developing in the agar plate (top two). In the bottom two photos you can see (x400 magnification) the root hairs coming off of the roots and root cap, which is indicated in the bottom, left photo. The root cap is the end collection of cells that aids in protection for the roots as it tunnels underground.
*Photos by Josh
C-fern roots developing in the agar plate (top two). In the bottom two photos you can see (x400 magnification) the root hairs coming off of the roots and root cap, which is indicated in the bottom, left photo. The root cap is the end collection of cells that aids in protection for the roots as it tunnels underground.
*Photos by Josh
ABOVE PHOTOS (3)
The above picture is showing the collection of cells from the onion (Allium cepa) that have been "squashed" on the slide so that a better view of the cells going through mitosis can be seen. Below and to the right is a zoomed in view from x400 magnification of these cells undergoing mitosis. You can see cells in the distinct anaphase where the chromosomes have been split and the it is beginning to go into telophase then mitosis will be complete, leaving two daughter cells.
*Photos by Josh
The above picture is showing the collection of cells from the onion (Allium cepa) that have been "squashed" on the slide so that a better view of the cells going through mitosis can be seen. Below and to the right is a zoomed in view from x400 magnification of these cells undergoing mitosis. You can see cells in the distinct anaphase where the chromosomes have been split and the it is beginning to go into telophase then mitosis will be complete, leaving two daughter cells.
*Photos by Josh
ABOVE PHOTOS (2)
Here are cross-sections of roots in maize (Zea Mays) and a pea plant (Pisum sativum). Labeled in the photo are the different cell types and structures in the roots. Maize, is a monocot, which are described as plants whose seeds have only one embryonic leaf. The pea plant, however is a dicot. Dicots are characterized by the seed having two embryonic leaves or cotyledons.
*Photos by Brendin and Josh
Here are cross-sections of roots in maize (Zea Mays) and a pea plant (Pisum sativum). Labeled in the photo are the different cell types and structures in the roots. Maize, is a monocot, which are described as plants whose seeds have only one embryonic leaf. The pea plant, however is a dicot. Dicots are characterized by the seed having two embryonic leaves or cotyledons.
*Photos by Brendin and Josh
ABOVE PHOTOS (2)
Here is a Tradescantia zebrina. It is unique because when a sample is taken from the mother plant and the leaves are removed (except for a few at the tip) and placed in water, after a week or so the cut ends from the stem will sprout root tips. We have taken a couple samples and are going to see if our samples sprout! Tune in next week for results!
*Photos by Brendin
Here is a Tradescantia zebrina. It is unique because when a sample is taken from the mother plant and the leaves are removed (except for a few at the tip) and placed in water, after a week or so the cut ends from the stem will sprout root tips. We have taken a couple samples and are going to see if our samples sprout! Tune in next week for results!
*Photos by Brendin
ABOVE PHOTOS (5)
Here (top) is the sporophyte that we grew from our spores in the past weeks. It has leafed and the roots have grown deep in the agar plate. We took a few samples from our plates and have transplanted them into cups with enriched soil. (Far left) Wicking paper was added to the bottoms of the cups to absorb moisture into the soil for growth. In the next few weeks they should grow into bigger plants a few inches tall.
"My favorite part of this lab was finding the cells in the onion that were going through mitosis. I have seen pictures of that in a million text books but never in life, lab, or field. That was really really cool. SCIENCE!"
- Josh
"I liked making the squash slide of the onions cells. We could see the cells in mitosis and then had it shown to the whole class. If you ask me, I think it went pretty well."
- Brendin
*Photos by Josh and Brendin
Here (top) is the sporophyte that we grew from our spores in the past weeks. It has leafed and the roots have grown deep in the agar plate. We took a few samples from our plates and have transplanted them into cups with enriched soil. (Far left) Wicking paper was added to the bottoms of the cups to absorb moisture into the soil for growth. In the next few weeks they should grow into bigger plants a few inches tall.
"My favorite part of this lab was finding the cells in the onion that were going through mitosis. I have seen pictures of that in a million text books but never in life, lab, or field. That was really really cool. SCIENCE!"
- Josh
"I liked making the squash slide of the onions cells. We could see the cells in mitosis and then had it shown to the whole class. If you ask me, I think it went pretty well."
- Brendin
*Photos by Josh and Brendin