CS8.1 Grade 8 Cells, Tissues, Organs, and Systems (grade 8) Overview: Students will analyze the characteristics of cells, and compare structural and functional characteristics of plant and animal Students will observe and identify cell structures (e.g., cell wall, cell membrane, vacuole, nucleus, cytoplasm, mitochondria, and chloroplast) and identify which are found in plant cells and which are found in animal They will work cooperatively with team members to develop and carry out a plan to construct a representation (e.g., model, drawing, sculpture, or dance) of the structures and functions of plant and animal cells Materials: On line videos as indicated in lesson. Handout sheet of cell parts to be included in representation (given below) Background: The basic unit of life is the cell. Every living thing is made up of All cells have many functions which keep an organism alive. Each organism has its own kind of Human cells are different from cow cells as are tree cells, frog cells, turnip cells and so on. Even within a specific organism there are different kinds of Think of a person; we have brain cells, bone cells, stomach cells and many other kinds. We have up to around 100 trillion Of these many are continually dying while others are forming. Plant cells are different from animal cells in several ways. One big difference is that the plant cells are larger than those of animals. Before we go into other differences we must find out what parts cells are made up of. This class we will just consider the major parts. They can be further broken down into more detail and other ones exist but learning the ones we will look at this class will give you a good start in the study of ** Show the class the following you-tube video to introduce them to It is a general cell video lasting 3:36 minutes called Discover video - It is found at www.youtube.com/watch?v=u54brpbsogs(cut and past the address into the you-tube site for quick access.) We will start by identifying the parts of a plant cell. Remember the plant cells are generally larger than animal cells yet we still need a microscope to see any of them. The parts we want to concentrate on are: (remind the students that if they look on the internet they will find more detailed information but you are only interested in these more basic components.)
1. cell wall - a thick, rigid membrane that surrounds a plant cell. It gives the cell most of its support and structure. The cell wall also bonds with other cell walls to form the structure of the plant. Not found in animal 2. cell membrane - the thin layer that surrounds the cell, but is inside the cell wall. The cell membrane is semipermeable, allowing some substances to pass into the cell and blocking others. Animal cells start with the membrane in that they do not have a cell wall. 3. nucleus- spherical body containing many organelles, including the nucleolus. The nucleus controls many of the functions of the cell kind of like an instructor. It is round and near the cell centre. 4. nucleolus - an organelle that is a small round body of protein in a cell nucleus. 5. cytoplasm - - the jellylike material outside the cell nucleus in which the organelles are located, they all sort of float in it. 6. vacuole - a large, membrane-bound space within a plant cell that is filled with fluid. Most plant cells have a single vacuole that takes up much of the cell. It helps maintain the shape of the cell and can be considered the storage warehouse. Animal cells likely have several small vacuoles in the cell. 7. mitochondrion - converts the energy stored in glucose, sort of a power plant. 8. chloroplast - contains chlorophyll and uses the sun energy to convert it into chemical energy. It is usually represented as an oblong shape with lines in it. Not found in animal 9. golgi complex - a flattened, layered, sac-like organelle that looks like a stack of pancakes. The golgi is like a packaging plant that gets things ready to be sent out. 10. ribosome is where proteins are assembled, small round like balls. 11. endoplasmic reticulum this organelle is a maze of tubes or tunnels several in each cell. 12. lysosome these organelles contain enzymes that aid in the digestion of nutrient molecules and other materials, they can be described as the stomach of the cell. They can be identified as looking like rods in the animal Plant cells differ from animal cells in that they have cell walls that give a sturdy structure plus they have chloroplast filled with chlorophyll to convert the suns energy and produce their own food. Lastly their vacuole is singular and large in that it fills up much of the cell. Cell wall, chloroplasts, one large single vacuole are found in plant cells not animal (Give the handout of the parts of the cell you just talked about so the students will know the parts you want them to be able to identify and know their general functions.) **Show the class the following student produced video that shows how he created a model of a plant cell compared to an animal cell. It is found on you-tube at Eli_cell_Project.mp4 simple Copy and paste the name in you-tube search bar. The video is 3.17 minutes.
Explain to the students that as they saw in the video that animals cells are more round and plant cells more square. Activity: Students are to create a representation of either a plant cell or an animal cell. Creativity and inclusion of the components and the ability to give a general description of their function are what the marks will be based on. Some ideas of how this can be accomplished are: Creating a color poster with the parts labeled Creating a model out of plasticine or play dough, or bread and candy or any other material you believe will work but label parts with toothpicks and paper signs. Creating a larger visual display using other students to represent organelles in the cytoplasm. For instants using chairs to represent the wall and then rulers for the membrane, the floor being the cytoplasm and placing students at different places with paper names on them to represent other organelles. Creating a video or power point explaining the components of an animal or plant cell. Or you can use a drawing program to draw it on the computer and label it. For the rest of this class students will do a rough sketch of the cell they are planning to represent. Then they will decide how they think they want to represent it for the class. Lastly they must make up a list of material they will need to complete their project. Next class students will bring the materials they need and complete the project. Each student will show their completed project to the rest of the class. A short assignment will be given so that students can demonstrate that they know what each organelles purpose is in the cell. Below is the handout to give to each student so that they know which parts of the cell they are to show in their model. Closure: It is important to learn of the building blocks of living things. Even if we cannot see them with the naked eye we must understand something about them to realize the complexity of life on earth. As you get further in your studies in science you will learn to use microscopes and see these fascinating cell structures for yourself. In order to appreciate what you will look at it is necessary to understand what makes up a cell.
Cell Parts that must be shown in your representation of either a plant or animal cell: (if creating an animal cell leave out the parts that do not apply) cell wall - a thick, rigid membrane that surrounds a plant cell. It gives the cell most of its support and structure. The cell wall also bonds with other cell walls to form the structure of the plant. Not found in animal cell membrane - the thin layer that surrounds the cell, but is inside the cell wall. The cell membrane is semipermeable, allowing some substances to pass into the cell and blocking others. Animal cells start with the membrane in that they do not have a cell wall. nucleus - spherical body containing many organelles, including the nucleolus. The nucleus controls many of the functions of the cell kind of like an instructor. It is round and near the cell centre. nucleolus - an organelle that is a small round body of protein in a cell nucleus. cytoplasm - the jellylike material outside the cell nucleus in which the organelles are located, they all sort of float in it. vacuole - a large, membrane-bound space within a plant cell that is filled with fluid. Most plant cells have a single vacuole that takes up much of the cell. It helps maintain the shape of the cell and can be considered the storage warehouse. Animal cells likely have several small vacuoles in the cell. mitochondrion - converts the energy stored in glucose, sort of a power plant. chloroplast - contains chlorophyll and uses the sun energy to convert it into chemical energy. It is usually represented as an oblong shape with lines in it. Not found in animal golgi complex - a flattened, layered, sac-like organelle that looks like a stack of pancakes. The golgi is like a packaging plant that gets things ready to be sent out. ribosome is where proteins are assembled, small round like balls. endoplasmic reticulum this organelle is a maze of tubes or tunnels several in each cell. lysosome these organelles contain enzymes that aid in the digestion of nutrient molecules and other materials, they can be described as the stomach of the cell. They can be identified as looking like rods in the animal cells and are not found in plant Practice labeling the parts in the cells above. This will give you a good idea on how to create your own representation.
Sample sheet of questions that can be given to students to test whether they know what each organelles general purpose is. Analysis Student Name 1. Name two things found in a plant cell that are not found in an animal cell 2. How does the shape of a plant cell differ from that of an animal cell? 3. What is the function of the chloroplasts? 4. What is the function of the vacuole? II. Briefly describe the function of the cell parts. 1. Cell membrane 2. Endoplasmic Reticulum 3. Ribosome 4. Golgi Complex 5. Lysosome 6. Mitochondriaon 7. Nucleus 8. Nucleolus