Leaf Collection Instructions

Arkansas is essentially a forest state because more than half of the state is covered with trees.  The climate and soils of Arkansas also support a great variety of trees, both conifers and deciduous.  Trees are one of Arkansas’ most important crops.  Forests are also valuable in preventing erosion, in offering parks and recreational areas, and in providing homes for wildlife.  In addition, many trees have been introduced into the state as ornamentals.

Leaf collecting is a good way to learn the trees native to your area.  Collecting leaves will also help you to learn leaf margins, shapes, and  venations and how to use different taxonomic keys to identify trees.

Materials needed:

  • leaf press
  • black ink pen
  • pencil
  • small notebook
  • scissors
  • Elmer’s glue
  • art paper, poster board, etc. for mounting
  • labels
  • taxonomic keys (Trees of Arkansas published by the Arkansas Forestry Commission)

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Directions for making a leaf press:
1.   Cut 15 – 20 pieces of corrugated cardboard 30 cm by 50 cm in size.
2. Cut several sheets of newspaper the same size as the cardboard.
3. Lay 10 or 12 sheets of newspaper between each cardboard layer sandwich style.  These sheets will need to be changed every couple of days as they absorb moisture from your leaves; therefore, cut extra sheets.
4. Use one, preferably two, stretch belts to bind the press together.
5. Leave the press in an area so that air can circulate &  more quickly dry the leaves.

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Getting started with your collection:
1. Study the shapes, margins, venations, tips, bases, etc. in your Trees of Arkansas book.

Click here to view reference page

2. Learn to distinguish simple leaves from compound leaves and conifers from deciduous trees.
3. Learn to distinguish a tree from a shrub.
4. Gather your collecting materials together – press, pencil, scissors, & small notebook.
6. Always get permission before collecting leaves on someone else’s property.
7. Be sure to collect at least
two of each type of leaf so both the bottom & top side of the leaf can be shown in your collection.
8. Place leaves in your press immediately after collecting them so they do not start to dry out and wrinkle.
9. Record the name of each leaf, date collected, and place collected in your notebook as you collect.  Also record tree characteristics such as shape of the crown, color and type of bark, etc.

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Collecting:
1. Remember to collect two of every type of leaf!
2. Carefully remove an entire leaf, not a leaflet, from the tree, and place this in your press between newspaper layers.
3. If leaves are damaged or torn, don’t use them because you will not receive credit.
4. Make sure that none of the leaf parts extend beyond the edge of the press.
5. You may also collect &press seeds and/or fruits from some trees if they fit in your press.
6. Leave the leaf in the press for 3 – 5 days depending on its thickness and moisture content.  Remember to change the newspaper when needed.
7. Keep the press in an area where air is circulating (in front of a fan).

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Labeling and identifying:
1. Obtain printed labels from your teacher.
2. Use only black ink to write labels, & do not mark out or white out mistakes on the labels; rewrite them.
3. Use taxonomic keys to identify each leaf, and include both the scientific & common name of the tree on the label.
4. Determine the shape, margin, tip, base, and venation of your leaf and whether it is a simple or compound leaf; record this on your label.
5. Use you key to give a description of the tree, not the leaf.
6. Research uses for the tree, its fruit, etc. and record on your label.
7. Tell if the leaf is deciduous or coniferous.

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Mounting leaves:
1. Use pieces of cut poster board or art paper to mount your leaves.  Make sure all sheets are uniform in size! (The size of your sheets will be determined by your largest leaf.)
2. Use Elmer’s glue to adhere two leaves to each page — one showing the upper surface of the leaf and the other showing the underside of the leaf.
3. Each page should have only one type of leaf on it.
4. Arrange the leaves so they do not overlap each other and so there is room to glue the label in the lower right hand corner.  The leaves should look nice on the page.
5. On compound leaves, mount the topside of the complete leaf and then mount the underside of a single leaflet. Make sure the leaflet comes from another leaf to receive credit!
6. Use a small amount of Elmer’s glue to adhere the completed label in the lower right hand corner of the page.
7. LET THE PAGES DRY COMPLETELY BEFORE ASSEMBLING THEM TOGETHER IN YOUR COLLECTION OR THE PAGES WILL STICK TOGETHER!!!!!
8. Once the pages are dry, lay them in the correct order (see your list of required leaves), and then number the pages in the lower right corner with black ink.
9. Make a stiff front and back cover for your collection from poster board, cardboard, wood, etc.  Include the following items on your cover:

  • title (Tree Identification Through Leaves)
  • your complete name
  • date collection turned into teacher
  • class period
  • subject
  • teacher’s name

10. Use ribbon, string, etc. to bind the pages together or assemble the collection in a scrapbook.  DO NOT COVER THE LEAVES WITH PLASTIC!!!

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Required leaves:
1. Only native, Arkansas trees may be used.  Refer to your Trees of Arkansas book.
2. Leaves must be in perfect condition without damage or tears.
3. No more then 4 oaks are allowed in the collection.
4. No fruit trees such as apple, pear, orange, peach, etc. are allowed.
5. Place the following leaves in your collection first and in this order:

  • sweet gum
  • American sycamore
  • pine (any type)
  • flowering dogwood
  • redbud
  • ash (any type)
  • persimmon
  • Eastern red cedar
  • red or silver maple
  • hickory (any type)
  • pecan
  • pin oak
  • willow oak
  • water oak
  • elm (any type)

6. The remaining leaves that you include must be trees native to Arkansas!

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*Pre AP Biology is required to collect 30 leaves including the 15 required.

 *Biology I is required to collect 20 leaves including the 15 required.

   Pre AP      Biology I

Introduction to Plants PPT Questions

Introduction to Plants
ppt Questions

Early Ancestors

1. The first habitat for plants on earth was _____________.

2. Which algal group is most related to early land plants?

3. What is this group of algae called?

4. List 5 similarities between algae and terrestrial plants.

     a.

     b.

     c.

     d.

     e.

5. List 5 helpful adaptations aquatic plants have by being surrounded by water.

     a.

     b.

     c.

     d.

     e.

6.Complete the following table explaining how terrestrial plants solved the move onto land.

 

Plant Adaptations to land
Problems: Solutions:
Need Minerals
Gravity
Increase in Height to get Light
Adaptations for drier environment
Reproduction

 

How Are Plants All Alike

7. All plants are ____________________.

8. Plants can make their own food by a process called ____________________.

9. Since plants make their own food they are called _________________.

10. Plants contain what type of chlorophyll?

11. Where is chlorophyll found in plants?

12. What surrounds the outside of all plant cells and what is it composed of?

13. How do plants store their reserve food?

14. The life cycle of plants is known as __________________ of _________________.

15. The dominant stage of the plant is the diploid (2n) ________________ stage.

16. The eggs and sperm are produced during the haploid (1n) ________________ stage.

17. The gametophyte stage produces a multicellular plant ______________ that is protected inside an ____________ ___________.

18. The sporophyte stage produces _____________ by _____________.

19. Haploid spores undergo ______________ to produce the _______________ stage.

20. The gametophyte stage makes _____________ called the _________ and ___________.

21. Label the diagram of alternation of generation. Include the sporophyte and gametophyte generations, the chromosome number (2n or 1n), and where mitosis and meiosis occur.

Plant Divisions

22. Plants are divided into __________ groups based on the presence or absence of an ___________ _____________ ___________ for carrying water and dissolved _____________.

23. What is the transport system for water and minerals called?

24. ______________ plants lack vascular tissue and are called _______________.

25. In what type of environment must nonvascular plants live?

26. Give an example of a bryophyte.

27. Nonvascular plants can’t grow as tall as vascular plants. Explain why.

 

28. The cells of nonvascular plants must be in _________ contact with water because water moves by _______________ from cell to cell.

29. How does the sperm get to the egg in nonvascular plants?

30. Name 3 divisions of nonvascular plants and give and organism found in each division.

     a.

     b.

     c.

31.Vascular plants are also called _______________.

32. What are the 2 subdivisions of vascular plants?

     

33. Name 4 divisions of seedless vascular plants and give an example of a plant in each group.

     a.

     b.

     c.

     d.

34. Name the 2 groups of seed-bearing vascular plants.

 

35. Gymnosperms have ____________ seeds found inside cones.

36. Angiosperms have ___________ to attract ____________ so seeds can be produced.

37. Name the division known as conifers and tell several plants in this group/

 

38. Name 2 other divisions of gymnosperms and tell a plant in each group.

     a.

     b.

39. Name the oldest living plant.

40. Name the tallest living plant.

41. What group are these 2 plants in?

42. Angiosperms are called ____________ plants.

43. How are seeds formed in angiosperms?

 

44. Where is the ovary found?

45. Name the male and female parts of a flower.

46. How are fruits formed?

47. Angiosperms are the division ______________.

48. What are the 2 subgroups of Anthophyta.

49. Describe the characteristics of monocots.

 

50. Describe the characteristics of dicots.

 

 

 

 

Chromatography of Plant Pigments Sample 2 PreAP

 

Chromatography of Plant  Pigments

 

Introduction

Chromatography is a way of separating a mixture using differences in the abilities of the components to move through a material. All chromatography involves two phases – a stationary phase and a mobile phase. The movement of the mobile phase through the stationary phase allows separation to take place. Because the components of a mixture move at different rates, they eventually separate.

Paper chromatography is a common way to separate various components of a mixture. The components of the mixture separate because different substances are selectively absorbed by paper due to differences in polarity. A solution can be separated by allowing it to flow along a stationary substance. Water or some other solvent is used as the mobile phase. The solvent moves upward along the paper because of capillary action. As it reaches the spot, the mixture dissolves in the solvent. For instance, the pigments in an ink solution can be separated by passing the ink through a piece of paper. The pigments respond differently to the paper. The differences in the migration rates result in differences in the distances the separated components travel, some pigments are held back while other moves ahead. Eventually, a pattern of colors results that shows the separated pigments.

Hypothesis

Paper can be used to separate mixed chemicals.

Materials

The materials used for this lab are paper, pencil, scissors, eraser, filter paper, test tube, cork, paper clip, metric ruler, black felt-tip pen, and a calculator.

Methods

The first step to this experiment was to bend a paper clip so that it is straight with a hook at one end. Push the straight end of the paper clip into the bottom of a cork stopper. Next, hang a thin strip of filter paper on the hooked end of the paper clip. Insert the paper strip into the test tube so it does not touch the sides, but almost the bottom of the test tube. Next, remove the paper strip from the test tube and draw a solid 5 mm wide band about 25 mm from the bottom of the paper, using a black felt tip pen. Use a pencil to draw a line across the top of the paper strip 10 cm from the top.

Pour about 2 mL of water into the test tube with the bottom of the paper in the water and the black band above the water. Observe what happens as the liquid travels up the paper. Record the changes you see. When the solvent has reached the pencil line, remove the paper from the test tube. Let the paper dry on the desk. With a metric ruler, measure the distances form the starting point to the top edge of each color. Record the data in a data table. Calculate a ration for each color by dividing the distance the color traveled by the distance the solvent traveled.

Results

The results of the experiment are shown in a chart and a graph.

Distance color traveled and Rf value.

 

Color of ink (list in order Distance traveled by each color (mm) Distance solvent traveled (mm) Ration traveled =
Distance color moved /Distance water moved
Yellow 50 120 5/12
Orange 85 120 17/24
Pink 100 120 5/6
Red 105 120 7/8
Blue 115 120 23/24
Violet 120 120 1

 

Questions

1. How many colors separated from the black ink? Six colors separated from the black ink: yellow, orange, pink, red, blue, violet.

2. What served as the solvent for the ink? Water served as the solvent because it is the universal solvent.

3. As the solvent travel up the paper, what color appeared first? Orange appeared first as the solvent traveled up the paper.

4. List the colors in order from top to bottom that separated from the black ink? The colors that separated from top to bottom: violet, blue, red, pink, orange, and yellow.

5. In millimeters, how far did the solvent travel. The solvent traveled 120mm.

6. From your results, what can you conclude is true about black ink. That black ink is a combination of several colors and that can be separated by water.

7. Why did the inks separate? The ink separated because each pigment has its own characteristics and molecular structure.

8. Why did some inks move a greater distance? Different pigments were absorbed at different rates.

Error analysis

There could be an error by the way the ink was distributed on the paper or by the amount of water put in the test tube.

Conclusion

The hypothesis was correct. This experiment showed the way black ink could be separated. Black ink is made from a various colors— yellow, orange, pink, red, blue, and violet. The colors separate because of the differences in their molecular characteristics, their solubility in water and their rate of absorption by the paper.

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Chromatography of Plant Pigments 3

 

 

Chromatography of Plant Pigments

 

 

Introduction:

 

Can chromatography be used to separate mixtures of chemical substances? The purpose of this experiment is to answer this question. In paper chromatography, a liquid sample flows down a vertical strip of absorbent paper, on which the components of a mixture are deposited in specific directions and locations. Chromatography is a tool used to examine and separate mixtures of chemical substances. Chromatography is essential to the separation of pure substances from complex mixtures. Separation results in a chromatographically pure substance. Chromatography allows you to determine the properties of chemical substances.

The relationship between the chromatography paper, mixture, and the solvent is very important in all chromatographic separations. The solvent has to dissolve the mixture that should be separated. The paper must also absorb the components of the mixtures selectively and reversibly. The substances making up the mixture must be evenly dispersed in the water. Chromatography is a simple and inexpensive tool for separating and identifying chemical mixtures if all these things are done.

 

Hypothesis:

 

Paper can be used to separate mixed chemicals.

 

Materials:

 

The materials used in this lab are filter paper, test tube, rubber stopper, paper clip, metric ruler, black felt-tip pen, pencil, calculator, and water.

 

Methods:

 

First, bend a paper clip so that it’s straight with a hook at one end. Push the straight end of the paper clip into the bottom of a cork stopper. Then, hang a thin strip of filter paper on the hooked end of the paper clip and insert the paper strip into the test tube. The paper should not touch the sides and should almost touch the bottom of the test tube. Next, remove the paper strip from the test tube. Now draw a solid 5-mm-wide band about 25 mm from the bottom of the paper, using a black felt tip pen. After this, use a pencil to draw a line across the paper strip 10 cm above the black band. Then, put the filter paper back into the test tube with the bottom of the paper in the water and the black band above the water. Observe what happens as the liquid travels up the paper and record the changes you see. When the solvent has reached the pencil line, remove the paper from the test tube. Let the paper dry on the desk. Finally, with a metric ruler, measure the distances from the starting point to the top edge of each color. Record the data in a data table and calculate a ratio for each color by dividing the distance, the color traveled by the distance the solvent traveled.

 

Results:

 

The results of the chromatography experiment are shown in a chart and a graph.

 

Color of ink (list in order) Distance traveled by each color (mm) Distance solvent traveled (mm) Ratio traveled = distance color moved divided by distance solvent moved
Yellow 70 108 0.65
Orange  

85

 

108

 

0.79

Pink 95  

108

 

0.88

Violet 102  

108

 

0.94

Blue 108  

108

 

1.00

 

 

 

Questions:

1. How many colors separated from the black ink? Five colors separated from the ink: yellow, orange, pink, violet, and blue.

 

2. What served as the solvent for the ink? Water served as the solvent for the ink.

 

3. As the solvent traveled up the paper, which color of ink appeared first? Dark blue appeared first.

 

4. List the colors in order from top to bottom that separated from the black ink? The colors separated in the order of: blue, violet, pink, orange, and yellow.

 

5. In millimeters, how far did the solvent travel? The solvent traveled 108 mm.

 

6. From your results, what can you conclude is true about black ink? Black ink is a mixture of several different colors.

 

7. Why did the inks separate? The inks separated because black ink is a mixture of different pigments that are soluble in water, have different molecular characteristics, and travel different distances.

 

8. Why did some inks move a greater distance? Some inks move a greater distance because molecules in ink have different characteristics, like how readily they are absorbed by paper. This means that the ink least readily absorbed by paper will travel farthest from the starting mark and the ink most readily absorbed by paper will be the closest to the starting mark. All of the different color inks that were separated were different in how readily they are absorbed by paper.

Error Analysis:

 

There are a few errors that could have changed the results. First, there could be inaccurate measurements of how far every color traveled or how far the water traveled up the filter paper. Another error could occur when calculating the ratio traveled, Rf value. Also, a longer test tube could have been used by different groups which would make the filter strip longer. This means that a group could have detected another color because they had more room on their filter paper. This also could have affected the ratios. Finally, the groups could have put different amounts of black ink on the filter paper.

 

Conclusion:

 

The hypothesis that paper can be used to separate mixed chemicals was correct. The different colored inks mixed together give the black its color. The five colors that separated from the black ink were blue, violet, pink, orange, and yellow. Blue appeared first and then was followed by violet, pink, orange, and yellow. The colors separated the way they did because they have different molecular characteristics, like how readily they were absorbed by the paper and their solubility in water. Blue was most readily absorbed by the paper and soluble by water, while yellow was the least.

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Chromatography of Simulated Plant Pigments

 

Chromatography of Simulated Plant Pigments

 

Introduction
    This experiment is conducted to investigate the components Plant Pigments separating visibly. There are a couple of different types of components in plant pigments, and they became clearly visible during this lab. The most important and abundant chemical pigment found in plants is chlorophyll. This pigment exists in two forms; chlorophyll a and chlorophyll b. Chlorophyll absorbs two main colors from light quite well. These are blue, and red. The chlorophyll reflects green light very well, however, the two different types of chlorophyll have their maximum absorption at different wavelengths of light. Chlorophyll a, being the main photosynthetic pigment, has a primary purpose to convert light energy to chemical energy used by the plant itself. Chlorophyll b absorbs light in a region of the spectrum apart from the dominant chlorophyll, and transfers the energy it produces to chlorophyll a. Along with chlorophyll b in transferring their energy produced to the dominant chlorophyll, two other pigments that are found in plants are carotenes and xanthophylls, which are orange and yellow respectively. Since chlorophyll is such a dominant pigment in green plants, this domination hides the color of the carotenes and xanthophylls in the leaves. This causes most plant leaves to appear green most of the time. During the autumn, however, the chlorophyll starts to break down, causing the carotenes and xanthophylls to show their bright red, orange and yellow colors.
These brilliant colors can be separated another way. This different technique, known as paper chromatography, separates mixtures in a liquid into individual components. The technique is based on the fact that each substance in a mixture has a specific affinity for a solid surface and a specific solubility in different solvents. By this method, the solid surface is the cellulose fibers in the chromatography paper, and the solvent is the solution that was placed in the bottom of the developing chamber.
This separation takes place through a process of absorption and capillary action. Just a small drop of the mixture, in this case plant pigment to be separated, is placed at the bottom of the strip of chromatography paper. The chromatography paper is then placed in the developing chamber with a solvent, which wicks up the paper, pulling the solvent up the paper by capillary action, and the mixture of pigments is dissolved as the solvent passes over it. The different components of the mixture move upward at different rates. A compound with greater solubility will travel farther than one with less solubility. The pigments then show up as color streaks on the chromatography paper. These substances have formed a pattern called a chromatogram on the chromatography paper.
The Rf values for each pigment is calculated to establish the relative rate of migration for each pigment. This value represents the ratio of the distance a pigment traveled on the chromatogram relative to the distance the solvent front moved.
Scientists use the Rf value of a sample to identify the molecule. Any molecule in a given solvent matrix system has a uniquely consistent Rf value. The formula for this value is as follows:

Rf = Distance each pigment traveled ¸ Distance solvent front traveled

 

Hypothesis
    Using paper chromatography, the pigments that give a leaf its color can be separated and observed to determine the Rf value of each pigment and their function during photosynthesis.

 

Materials
For this experiment the following items are used — one chromatography reaction chamber, one paper chromatography strip, one capillary pipette, a pencil and paper, calculator, ruler, 50 ml beaker, colored pencils, approximately 10 ml of solvent depending on the size of the reaction chamber, scissors, and simulated plant pigment.

 

Procedure
Use scissors to cut the bottom of the chromatography paper to a tapered end. Measure the strip and cut the length to equal slightly longer than the reaction chamber. Draw a faint pencil line at the bottom of the tapered end and use a capillary pipette to add some simulated plant pigment to this line. Add 5-10 ml of solvent to the reaction chamber. Extend the chromatography strip through the slit in the lids of the reaction chamber and carefully lower the strip into the chamber so the tapered end is in the solvent and the pencil line is above the solvent level. Make sure the strip does not touch the walls of the chamber and do not bump the chamber as the pigments begin to separate. After the pigments have completely separated and the solvent front has reached the top of the chamber, remove the strip and mark the solvent front with a pencil line before it evaporates. Measure and record the distance the solvent and each pigment traveled. Use a calculator to determine the Rf values for each pigment.

 

Data

 

Table 1

Band # Pigment Color Migration distance (mm) Rf value
1 Carotene Orange 59mm .94
2 Xanthophyll Yellow 56mm .89
3 Chlorophyll a Light green 29mm .46
4 Chlorophyll b Dark green 14mm .22
Solvent 63mm

Questions
1. Describe what happened to the original spot of simulated plant pigments?
  The solvent separated  the original spot by wicking up the solvent while dissolving the various pigments in the spot.
2. List some other uses of chromatography?  Chromatography can be used to separate various mixtures of subtances, liquids and gases.
3. Which of the 4 pigments migrated the furthest and why?  carotene ( orange) because it was the most soluble in the solvent
4. Which type of chlorophyll was the most soluble?  chlorophyll a
5. Explain why leaves change color in the fall?  In Autumn, chlorophyll starts to break down which allows the other brilliant plant pigment colors to show. These pigments include the red, orange, and yellow colors.
6. What is the function of plant pigments in photosynthesis?  Plant pigments trap light energy and convert it into chemical energy that can be used by the plant to make glucose or sugar.

Error Analysis
The chromatography paper touched the sides of the chamber during the waiting time which caused the migration to go slightly to the side instead of straight to the top. Also the strip was bent at the top so there could have been a slight error in measuring the migration of the solvent  front.

Conclusion
Paper chromatography proved to be an accurate method of separating and observing the various colors of plant pigments. The pigments dissolved in the solvent and migrated upward. The colors were observed and their migration distances measured & recorded. The
Rf value of each pigment was determined by dividing its migration by the migration of the solvent.  It was determined that 4 pigments were present in the original spot — carotene, xanthophyll, chlorophyll a, and chlorophyll b. Carotene was the most soluble, while chlorophyll b was the least soluble.