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Investigation: Comparing Plant and Animal Cells - Biology

Investigation: Comparing Plant and Animal Cells - Biology



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Part 1: Observing Plant Cells

  1. Obtain a piece of onion and use forceps to peel the membrane from the underside of the onion. This will appear very thin and mostly transparent.
  2. Place the membrane flat on the slide and use your forceps to spread it out, avoid having any folds in the membrane.
  3. Place a drop of iodine on the membrane. (Caution: iodine will stain skin and clothes too!)
  4. Carefully place a cover slip over the specimen.

View the microscope with scanning, low and high power objectives. You may need to review the steps of using the microscope. Draw your cells as they appear in the viewing field. On the 400x image, label the cell wall, nucleus, and cytoplasm.

Part 1: Observing Animal Cells

  1. Clean the slide you created with the onion by rinsing and drying it. Throw the cover slip away.
  2. Put a drop of methylene blue or other stain on the slide.
  3. Gently scrape the inside of your cheek with the flat side of a toothpick and stir the end of the toothpick into the stain to create a smear.
  4. Place a coverslip onto the slide. (Cover slips are small, thin, square plastic or glass pieces).

Draw your cells as they appear in the viewing field. On the 400x image, label the cell wall, nucleus, and cytoplasm.

Analysis

  1. Describe two ways in which the plant and animal cells are similar based on your observations.
  2. Describe two ways in which they are different based on your observations.
  3. Consider that there are many organelles and structures of the cell that were not visible using the light microscope. List two organelles that might have been visible if you were using a microscope that had a greater magnification.
  4. In both cases, a stain was used in the preparation of the slide. Why do you think staining is necessary?
  5. Create a Venn diagram that shows how plant and animal cells are different and the same. You should include information from your notes or textbook (not just observations from this lab.)

Comparing Plant and Animal Cells

Identify the differences between plant and animal cells and how these differences relate to their cellular functions.

Idea for Classroom Use

Cells are the smallest functional units of life in all organisms. Ask students, do all cells look the same? Which structures might be the same in both a plant and an animal cell? Which might be different?

Have students read and discuss the Plant Cell and Animal Cell infographics. In pairs, have students create a Venn diagram (or use the one provided) comparing and contrasting the two types of cells. When finished, have student discuss their findings as a class, summarizing the similarities and differences noted.

Ask students, how do cell structures relate to their function? One example of this is that plant cells have chloroplasts that allow them to perform photosynthesis for energy, but animal cells do not have chloroplasts since they get their energy elsewhere.

organisms that have a well-defined shape and limited growth, can move voluntarily, acquire food and digest it internally, and can respond rapidly to stimuli.

smallest working part of a living organism.

part of the cell in plants and other autotrophs that carries out the process of photosynthesis.

living or once-living thing.

process by which plants turn water, sunlight, and carbon dioxide into water, oxygen, and simple sugars.

organism that produces its own food through photosynthesis and whose cells have walls.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Director

Tyson Brown, National Geographic Society

Author

National Geographic Society

Production Managers

Gina Borgia, National Geographic Society
Jeanna Sullivan, National Geographic Society

Program Specialists

Sarah Appleton, National Geographic Society
Margot Willis, National Geographic Society

Last Updated

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Related Resources

Cell Biology

A cell is the smallest unit that is typically considered alive and is a fundamental unit of life. All living organisms are composed of cells, from just one (unicellular) to many trillions (multicellular). Cell biology is the study of cells, their physiology, structure, and life cycle. Teach your students about cell biology using these classroom resources.

Cell Functions

A cell is one of the building blocks of life. Cells are membrane-bound groups of organelles that work together to allow it to function. Some of the major organelles include the nucleus, mitochondria, lysosomes, the endoplasmic reticulum, and the Golgi apparatus. Plant cells also include chloroplasts, which are responsible for photosynthesis. Use these classroom resources to examine how cells function with your students.

Unicellular vs. Multicellular

Cells function differently in unicellular and multicellular organisms. A unicellular organism depends upon just one cell for all of its functions while a multicellular organism has cells specialized to perform different functions that collectively support the organism.


ENGAGEMENT

Objective Introduction

At the beginning of the lesson, the class will do a Think-Pair-Share to discuss the objective.

Class Activity

  1. Show students the PP slide with the microscopic image of both an animal and plant cell. Give them no further information than they are images of cells.

Student Activity

  1. Ask students to observe the PP slide of the microscopic image of cells.
  2. Hopefully, they remember learning what cells are in their Cell Theory Unit.
  3. Ask the students to list any differences they see between the two images.
  4. Have the students hypothesize about what image might be.
  5. Explain to them that the image on the right is an animal cell and the image on the left is a plant cell.
  6. Ask if they see anything inside each cell and hypothesize what they might be.
  7. Explain that today they will be learning what the difference is between an animal cell and a plant cell. They will also be learning about the organelles inside each cell and what its function is.

The teacher will help to clear any misconceptions about animal and plant cells. Some may be that all cells are the same size and shape, plants are not made of cells, and that some living parts of organisms are not made of cells.

Estimated Class Time for the Engagement: 20-30 minutes


Comparing Plant and Animal Cells

Identify the differences between plant and animal cells and how these differences relate to their cellular functions.

Idea for Classroom Use

Cells are the smallest functional units of life in all organisms. Ask students, do all cells look the same? Which structures might be the same in both a plant and an animal cell? Which might be different?

Have students read and discuss the Plant Cell and Animal Cell infographics. In pairs, have students create a Venn diagram (or use the one provided) comparing and contrasting the two types of cells. When finished, have student discuss their findings as a class, summarizing the similarities and differences noted.

Ask students, how do cell structures relate to their function? One example of this is that plant cells have chloroplasts that allow them to perform photosynthesis for energy, but animal cells do not have chloroplasts since they get their energy elsewhere.

organisms that have a well-defined shape and limited growth, can move voluntarily, acquire food and digest it internally, and can respond rapidly to stimuli.

smallest working part of a living organism.

part of the cell in plants and other autotrophs that carries out the process of photosynthesis.

living or once-living thing.

process by which plants turn water, sunlight, and carbon dioxide into water, oxygen, and simple sugars.

organism that produces its own food through photosynthesis and whose cells have walls.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Director

Tyson Brown, National Geographic Society

Author

National Geographic Society

Production Managers

Gina Borgia, National Geographic Society
Jeanna Sullivan, National Geographic Society

Program Specialists

Sarah Appleton, National Geographic Society
Margot Willis, National Geographic Society

Last Updated

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

Media

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our Terms of Service.

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources

Cell Biology

A cell is the smallest unit that is typically considered alive and is a fundamental unit of life. All living organisms are composed of cells, from just one (unicellular) to many trillions (multicellular). Cell biology is the study of cells, their physiology, structure, and life cycle. Teach your students about cell biology using these classroom resources.

Cell Functions

A cell is one of the building blocks of life. Cells are membrane-bound groups of organelles that work together to allow it to function. Some of the major organelles include the nucleus, mitochondria, lysosomes, the endoplasmic reticulum, and the Golgi apparatus. Plant cells also include chloroplasts, which are responsible for photosynthesis. Use these classroom resources to examine how cells function with your students.

Unicellular vs. Multicellular

Cells function differently in unicellular and multicellular organisms. A unicellular organism depends upon just one cell for all of its functions while a multicellular organism has cells specialized to perform different functions that collectively support the organism.


Deep Dive into the Cell

Students explore the smallest level of organization of the human body: the cell. They compare plant and animal cells by examining infographics that illustrate cell structures and relating them to organism functions.

This lists the logos of programs or partners of NG Education which have provided or contributed the content on this page. In collaboration with

1. Project two visualizations to show the smallest level of organization of the human body: the cell.

  • Show the Cell Size and Scale interactive to portray the small scale at which cells exist.
  • Then show the Animal Cell infographic and give students some time to orient to the details and features of the cell.
  • Have students make connections to microbes by asking them to share their initial observations about the features of an animal cell.     
      • Ask: What do you notice? What does this remind you of? How does it relate to the microbes you learned about in the Introduction to Microbes and Human Body Systems and Microbes Across the Tree of Life activities(Possible responses: Many of the microbes were single-celled organisms. Some microbes that we learned about were microscopic animals, but others had simpler cell organization, such as bacteria.)

      2. Use infographics to compare features of plant and animal cells.

      • Distribute the Deep Dive into the Cell Investigation Guide explain that this organizer will help students track their learning during this activity.
      • Have students access the Plant Cell infographic and Animal Cell infographic on computers or distribute printed handouts. Ask students to use the table in Part A of the Investigation Guide to record the cell structures, their locations, functions, and which type of cell they are found in.
      • Then follow the steps below to have students identify and discuss the common features that the two cell types share and that are distinct.
      • Cells are the smallest functional units of life in all organisms. Ask students: Do all cells look the same? Which structures might be the same in both a plant and an animal cell? Which might be different?
          • Have students read and discuss the Plant Cell and Animal Cell infographics. In pairs, have students create a Venn Diagram (or use the one provided) comparing and contrasting the two types of cells. When finished, have student discuss their findings as a class, summarizing the similarities and differences noted.
          • Ask students: How do cell structures relate to their function? (One example of this is that plant cells have chloroplasts that allow them to perform photosynthesis for energy, but animal cells do not have chloroplasts since they get their energy elsewhere.)
          • After discussing the similarities and differences between plant and animal cells, have students complete the synthesis question at the end of Part A. Tell them:
            • Write a claim about how the plant cell’s additional organelles help it to function. Support your claim with evidence from what you know about plants and their unique abilities. (Possible claims: Cell wall provides additional structure for a plant, chloroplasts are needed to photosynthesize, larger vacuole stores liquid and helps to maintain cell structure.)

            3. Conduct an investigation to compare different types of cells and a nonliving item.

            • Introduce the lab and review the lab procedures, as detailed in Part B of the Investigation Guide. If you have selected specific nonliving items for students to choose from in the third part of the investigation, present those at this time.
            • Review safety protocols for carrying out lab investigations. None of the chemicals or procedures in the lab investigation are dangerous, but students should use caution when swabbing their cheek with a toothpick and when using the microscopes.
            • Distribute materials and have students complete the lab investigation in the same partner groups as in Step 2.
            • During the lab, circulate to support students in using the lab tools as well as accurately viewing and interpreting their view of the items under the microscope.
            • At the conclusion of the lab, students should respond to the synthesis questions in their Investigation Guide.

            4. Lead a discussion to debrief and ensure students’ understanding of the previous activities.

            • Elicit students’ responses to the synthesis questions in Part A and B from the Investigation Guide. Build on students’ ideas as you facilitate a debrief discussion about the key features and functions of cell organelles, important differences between plant and animal cells, and how their investigation provided evidence that living things are made up of cells.

            5. Revise Human Body Microbial Maps in original small groups for students to reflect on their learning and add in new understanding about cells.   


            Learning Goals

            • The students will use guided, structured scientific inquiry to collect and record data on animal and plant cell parts/characteristics and then draw or create a model of a simple plant or animal cell, correctly labeling the parts.
            • The student will use a journal to record observations and drawings as they collect data.
            • The students will demonstrate their understanding of the parts/characteristics of plant and animal cells by identifying their classmates' drawings/model of a cell as either plant or animal.

            Differences Between Plant and Animal Cells

            The differences between plant and animal cells cannot the naked eye. However, the impacts of these differences on the morphology (form and features) of plants and animals is noticeable. Without chloroplasts, a cell wall and a central vacuole, animals cells are able to do certain things that plant cells cannot, and vice versa.

            As connected units, such as body tissue, animal cells are able to allow for more fluid movement than plant cells, which are stiffly attached to their neighbors by cell walls. As individual units, animal cells are also able to move freely about the organism when necessary, or switch roles to specialize in another task. Plant cells are less able to do this because of the plant cell walls keeping them in place.

            What plant cells (and plants) lose in physical freedom from cell walls and central vacuoles, they gain in self-reliance and security. Cell walls, central vacuoles and chloroplasts all contribute to plant cells' autotrophism, which frees them from reliance on the need for organic matter for nutrition. Plants do not need to scavenge, hunt or or forage for food. While animals battle for resources and engage in sexual reproduction, plants stay rooted and grow toward the sun.


            Plant Cell Vs. Animal Cell Similarities

            Cell Type

            Both plant and animal cells are eukaryotic in nature, having a well-defined membrane-bound nucleus.

            Nucleus

            It is present in both cell types. The nucleus carries most of the genetic material in the chromosomes, which carry the genetic information in the form of DNA (deoxyribonucleic acid).

            Cell Membrane

            It is a semi-permeable or selectively-permeable membrane that encloses the contents of a cell, allowing only selected molecules to enter the cell and blocking out the others.

            Mitochondria

            They act as the powerhouse of the cell, converting food into energy. Animal cells have more number of mitochondria, as they are the only source of energy. They also contain a small amount of DNA.

            Endoplasmic Reticulum (ER)

            These membrane-bound organelles consist of a series of sac-like structures that help in the production of proteins and lipids, and their transportation to the Golgi apparatus. Rough ER helps in transporting proteins and smooth ER aids in the production of lipid.

            Ribosomes

            They act as sites, where proteins synthesize from amino acids. Some ribosomes are attached to the endoplasmic reticulum, while others float freely in the cytoplasm.

            Golgi Bodies/Apparatus

            It is a flattened sac-like structure which receives and processes proteins from the endoplasmic reticulum, and transports them to various locations within the cell or sends them out of the cell.


            Observations

            When observing the onion skin cell, we noticed that the cells took on a brick-like structure and within the cells, small dots (the nuclei) can be seen. When we first looked into the microscope, the microscope’s total magnification was 40X so there were about a hundred rows of rectangular

            cells (see diagram provided), but as we changed magnifications, the number of cells in the field of view decreased.

            When we viewed the onion skin cells at 400X total magnification, we noticed the nuclei of the cells looked clearer and larger and we were able to study the cell with more understanding than when we used the first magnification.

            The organelles that we were able to see in this type of cell were the nucleus, the cytoplasm, and the cell wall. Unlike the onion skin cells, the cheek cells were more spread out from each other and they

            all had a round shape. When we viewed the cheek cells at 40X total magnification, we noticed that the cells were secluded and spread out (see diagram provided). At 400X total magnification, we were only able to view one cell at a time, due to the fact that the cells were separated from each other.

            The organelles that were visible in this type of cell were the nucleus, the cytoplasm and the cell membrane. Aside from the actual cells, we were able to see air bubbles within both the onion skin cell slide and the cheek cell slide.


            Investigation: Comparing Plant and Animal Cells - Biology

            Cells are the basic functional units of all living organisms. They may exist singly or in aggregates. When cells join together to take to take on a specialized function within a larger organism, they form a tissue.
            There are two major divisions into which all cells fall: prokaryotic (organized nucleus absent) and eukaryotic (organized nucleus present). Bacteria make up the former division while the cells of plants, animals, fungi, protozoa, and algae compose the latter.
            Animal and plant cells share characteristics, which you will observe in this lab. They also differ in several important ways. Both animal and plant cells may occur unicellularly or within multicellular organisms. Because they often take on special functions within tissues, animal cells are frequently more specialized than plant cells. Epithelial (EP-uh-THEE-lee-ul) cells and blood cells are examples of different tissues.
            In this lab, you will look at epithelial cells in both plants and animals. Epithelial cells form the skin of the body surfaces and the linings of the inner surfaces. These cells are specialized for transportation of substances and protection. The individual cells of these layers may be shaped like cubes, columns, or be flat, depending on their location and function.

            Compound microscope
            Microscope slides
            Cover slips
            Forceps (tweezers)
            Single-edged razor blade
            Flat-edged toothpicks
            Paper towel
            Iodine solution
            *Methyl-green stain
            Onion
            Sprigs of Elodea
            Pictures of typical plant and animal cells from a textbook for reference

            *You can get a good substitute stain at the pet store. Either the green or the blue tropical fish medicine works great as a stain.

            Place a beaker of water with the Elodea in it, under a strong light source about 30 minutes before the lab.

            Onion bulbs are organized tissue that, under the appropriate conditions, will give rise to an entire plant. The curved pieces that flake away from a slice of onion are called scales. On the underside of each scale is a thin membrane called the epidermis.

            1. Obtain a piece of onion and remove one of the scales from it. Use forceps to pull away the epidermis from the inner surface. Be careful not to wrinkle the membrane. Place a drop of water on the center of a microscope slide, cut a piece of membrane about 0.5 cm square with a single-edged razor blade. CAUTION: Handle the razor blade with care. Using a toothpick to straighten out any wrinkles, place the membrane sample in the drop of water. Take a cover slip, and carefully place it over the sample, lowering it at an angle to the slide. This helps keep air from being trapped under the cover slip. You have just made a wet mount.

            2. Examine the epidermis first with the medium power objective of your microscope. Unstained specimens are often seen better with less light. Try reducing the illumination by adjusting the diaphragm of the microscope. Then examine it under high power.

            Question 1. How many layers thick is the epidermis?

            Question 2. What is the general shape of a typical cell?

            3. To stain your specimen, remove your slide from the microscope stage. Place a drop of iodine on the side of the cover slip, touching its edge. CAUTION: iodine is toxic. Draw the water from underneath the cover slip with a scrap of paper towel placed edge to the opposite side of the cover slip from the iodine drop. The stain will be drawn under the cover slip to replace the water that the paper towel scrap absorbs.

            4. Place the slide back on the microscope stage and observe as before. The iodine will stain the nucleus so it can be seen more clearly.

            Question 3. What does the nucleus look like under medium and high power?

            Question 4. Within an individual cell, where are the cytoplasm and the nucleus found? What general characteristic of plant cells can be inferred from observations of the cytoplasm and nucleus?

            Question 5. Make a diagram of several cells as observed under high power. Label the following structures in one cell: nucleus, cell wall, central vacuole, cytoplasm.

            5. Obtain a single leaf of Elodea (from the young leaves at the tip) and prepare a wet mount as you did before. You may want to use only a small portion of the leaf tip, so it will lay flat on the slide.

            Question 6. What does Elodea look like under middle power?

            6. Examine the chloroplasts under high power.

            Question 7. What does a single chloroplast look like?

            Question 8. Are the chloroplasts moving or stationary? Make an inference to explain this.

            Question 9. In what ways are the cells of onion epidermas and Elodea similar? Different?

            Question 10. What observable characteristics can be used as evidence for classifying a specimen as a plant? Use information from your textbook to help you with this question.

            7. Prepare a slide of epithelial cells from your oral cavity, by the following procedure. Take a flat toothpick (a NEW one) and using the large end, scrape the inside of your cheek 3 or 4 times. Gently make a smear in the center of a clean slide, about the size of a dime. Carefully place 1 drop of methyl-green stain on the center of the smear. Place a cover slip over the drop of stain.

            8. Examine the cells, first under middle power, then under high power. At first, the field of view will be light blue and the cells will be a slightly darker blue. After a few minutes, the field will lighten and the cells will become slightly purple.

            Question 11. Inside the mouth, these cells are joined together in a sheet. Why are they scattered here?

            Question 12. How are these animal cells different from the plant cells you observed?

            Question 13. Draw a few cells and label the cell membrane, nucleus, and cytoplasm.


            Key Differences Between Plant and Animal Cytokinesis

            1. Cytokinesis merely refers to the process of cell motion or cell division, in which both a plant and animal cell develops into two nascent cells via a cell plate and contractile ring formation, respectively.
            2. The mode of cytokinesis is one of the most critical features that differentiate the mechanism of the cell division in the plant and animal cell. A plant cell produces daughter cells by the cell-constriction mechanism or through the formation of cell-furrow. Oppositely, the animal cell forms two nascent cells by the fusion of phragmoplast associated vesicles at the metaphase plate.
            3. Vesicles form during the telophase stage of the plant cell, which later moves towards the phragmoplast and fuse with each other to develop a thick cell plate. But, there is no such vesicle formation, and fusion occurs during the cytokinesis of the animal cells.
            4. Cell abscission occurs via a centripetal expansion of the contractile ring in animals, and through centrifugal expansion in plant cells.
            5. The formation of a mid-body during the cytokinesis process is one of the most striking features that differentiate the plant and animal cell cytokinesis. A plant cell possesses a mid-body of phragmoplast (remains of mitotic spindles) and some vesicles filled with the cellular material. In contrast, an animal cell has a mid-body of actin and myosin-II microfilaments that form a concentric contractile ring within the cell.

            Similarities

            1. Both the plant cell and animal cell cytokinesis are essential for cell growth and development.
            2. The cell division in plant and animal cell facilitates the equal distribution of the nuclear and cytoplasmic contents between the two daughter cells.
            3. Both the plant cell and animal cell cytokinesis lasts till the telophase stage of the cell division cycle.
            4. Both the processes occur after the chromosomal segregation.

            Conclusion

            Thus, we can conclude that the process of cytokinesis is a crucial event in the cell cycle that ensures the uniform partitioning of the nuclear and cytoplasmic contents between the two developing cells. Cytokinesis generally involves the extensive restructuring of the cellular contents, and it begins after the chromosomal segregation. In both plant and animal cell, the event of cytokinesis is a pivotal step for cell growth and development.


            Watch the video: Four Leaves Experiment to demonstrate Stomatal transpiration (August 2022).