Lesson 4.1 Cells - Life's Smallest Units

Lesson 4.1 – Cells: Life’s Smallest Units

Preface Cells are the basic unit of life. Cells range from single-celled organisms to a component of complex tissues that perform highly specialized functions. As tiny as cells are, cells can be broken down even further into the various parts called organelles that provide structure and function for all living things. Cells of a plant form its architecture and are central to what makes a plant specific and unique.

The exploration of plant cells in this lesson will provide students an opportunity to learn each cell part and begin to understand the contribution a cell makes to the function of a plant. Students will learn about the anatomical characteristics of cells and the similarities and differences of plant and animal cells. Students will draw and label the parts of a plant and animal cell to help them to understand the function of cell parts.

Cellular biology is a very challenging and interesting field of study. With the recent advancements in biotechnology, such as genetic engineering and cancer research, there are many opportunities to provide students with experience required for a future career in cellular technology. Students can consider job shadowing or an internship with a local university scientist or biotechnician.

For more information regarding opportunities related to a Supervised Agricultural Experience (SAE) program and examples of SAE projects, view the webpage at the following URL: http://www.ffa.org/index.cfm?method=c_programs.SAE.

Emerging Agricultural Technology is a proficiency award area in FFA that recognizes students for their accomplishments in SAE programs associated with activities related to new and emerging agricultural technologies. These new technologies include agriscience and biotechnology laboratory experiences.

If this is an area of interest for students, help to get them started with the experience today. For more about the National FFA Organization, review the information found at the following URL: http://www.ffa.org/.

The National Council for Agricultural Education – CASE – Copyright 2010 Plant – Unit 4 – Lesson 4.1 – Cells: Life’s Smallest Units – Page 1 All of the components of a cell make the whole of a working system. If one part of the cell fails, the cell will perish. In other words, cell components use teamwork to accomplish cell function. Teamwork is needed in all occupations to accomplish goals of a group. Help students use this analogy to learn from cells about the value of teamwork.

The above statement relates to LifeKnowledge® Precept B5 “Participate effectively as a team member.” A variation of the “Picasso Moment” E-Moment® is incorporated as a reinforcement strategy for the visual representation of plant cell parts and their function.

For more about LifeKnowledge® and E-Moments® review the information found at http://www.ffa.org/ageducators/lifeknowledge/index.html.

Concepts 1. Plant cells share similarities and differences with animal cells. 2. Plant cells are comprised of many parts that have essential functions for the survival of plant tissue, such as respiration. 3. Cell organelles can only be seen using a microscope. 4. There are different classifications of cells based on their utility. 5. New plant growth is not possible without meristematic tissues. 6. Cells use water, oxygen, and glucose to produce energy and metabolic by- products of carbon dioxide and water.

Performance Objectives It is expected that students will  Identify and label plant and animal cell organelles.  Distinguish structural differences between plant and animal cells.  Develop a pictorial representation of cell function.  Correctly prepare slides of plant cells for viewing under a microscope.  Collect and analyze data to provide evidence of cell metabolism.

Critical Thinking and Application Extensions Interpretation 7. Students will diagram a common object or entity, such as a car or a factory, and connect the analogous relationships between the common object and the functions of the cell to reinforce their understanding of cells. Perspective

The National Council for Agricultural Education – CASE – Copyright 2010 Plant – Unit 4 – Lesson 4.1 – Cells: Life’s Smallest Units – Page 2 8. Students will construct a model to simulate the size comparison of organelles. On a piece of poster board, students will use everyday items to represent the relative size of each organelle. Self-Knowledge 9. Students will list their previous misconceptions about cell parts and functions, write a reflection about why they perceived cell parts and functions in an incorrect way, and develop a teaching activity for educating other students about cell parts and function.

Essential Questions 1. What is a cell? 2. What are the parts of a cell? 3. How are cells classified? 4. How are animal and plant cells similar? 5. What is the function of cell organelles and how do they work together? 6. How do cells perform plant functions? 7. How do plant cells convert raw nutrients into energy? 8. How is cellular respiration and cellular metabolism related? 9. Why is knowing about plant cells important to understanding plants and plant systems?

The National Council for Agricultural Education – CASE – Copyright 2010 Plant – Unit 4 – Lesson 4.1 – Cells: Life’s Smallest Units – Page 3 Key Terms Aerobic Anaerobic Anatomy Pertaining to organisms Living or active in the The branch of biology that grow only in the absence of free oxygen. that deals with the presence of oxygen, as structure of organisms. bacteria in a properly prepared compost.

Apical Tissue Cell Cell Membrane Relating to the apex or tip The ultimate functional Also called the plasma of shoots and roots. unit of an organic membrane, or structure, plant, or plasmalemma. A animal. It consists of a selectively permeable, microscopic mass of limiting membrane protoplasm, which surrounding the includes a nucleus protoplasm. surrounded by a membrane. In most plants, it is surrounded by a cell wall. Cell Wall Centrosome Chloroplast The membranous A minute protoplasmic Minute objects within covering of a cell secreted body sometimes held to plant cells which contain by the cytoplasm in be the dynamic center of the green pigment, growing plants. It consists mitotic activity. chlorophyll. largely of cellulose, but may contain chitin in some fungi and silica in some algae.

Cytoplasm Dicot (Dicotyledon) Endoplasmic The living substance Plant whose seeds have Reticulum within a plant or animal two cotyledons or seed Structure extending cell excluding the nucleus. leaves, such as beans. throughout the cytoplasm of a cell. It functions in the transport of cell products and as a surface for protein synthesis by the ribosomes. Epidermis Tissue Eukaryote Golgi (apparatus) The cellular layer of an Genetic information or Cell organelle, important organism; the outer skin. DNA contained in the for glycosylation and nucleus like most secretion in cells. organisms. Ex: Plants and animals.

The National Council for Agricultural Education – CASE – Copyright 2010 Plant – Unit 4 – Lesson 4.1 – Cells: Life’s Smallest Units – Page 4 Lateral Lysosome Meristems A directional or positional An organelle bounded Plant tissue capable of term meaning away from by a membrane and cell division and the middle or toward the containing enzymes therefore responsible for side. capable of breaking growth. down proteins and other molecules.

Metabolism Mitochondria Monocotyledon Physical and chemical Cell organelles Plant having a single processes in an organism composed of an outer cotyledon or seed leaf by which living matter is membrane and a such as corn. produced, maintained, and winding inner destroyed, and by means membrane. A series of of which energy is made chemical reactions that available. occur on the inner membrane convert the energy of oxidation into the chemical energy of ATP. Nucleolus Nucleus Organelle A spherical body found The central portion of The inside parts of a cell, within the nucleus of a the cell protoplast such as the Golgi eukaryotic cell. surrounded by a very apparatus, nucleus, thin membrane. It ribosomes, microtubles, consists of nucleoplasm and storage particles. and includes within itself variously arranged chromatin, nuclear sap, and nutritive substances. Parenchyma Peroxisome Phloem Cells with thin cell walls In the plant cell, use Inner bark; the principle and with large vacuoles. In oxygen to carry out tissue concerned with leaves, parenchyma cells catabolic reactions. the translocation of contain chloroplasts for elaborated food photosynthesis. produced in the leaves, or other areas, downward in the branches, stems, and roots. Photosynthesis Prokaryotes Protoplast Process by which green Cell with DNA not A unit of protoplasm in plants, using chlorophyll enclosed in a nucleus. one cell. and the energy of sunlight, Ex.: bacteria. produce carbohydrates from water and carbon dioxide, and release oxygen.

The National Council for Agricultural Education – CASE – Copyright 2010 Plant – Unit 4 – Lesson 4.1 – Cells: Life’s Smallest Units – Page 5 Protoplasm Respiration Ribosome The gelatinous, colloidal A chemical process that A particle that lies along material of plants and takes place in living cells the endoplasmic animals in which all life whereby food (fats, reticulum and is activities occur. carbohydrates, and composed of a protein proteins) is “burned” portion and RNA. The (oxidized) to release site of protein synthesis. energy and waste products, mainly carbon dioxide and water. Living things use energy produced through respiration to derive vital life processes, such as growth and reproduction. Tissue Vacuole Xylem Groups of cells working A cavity that is within the The “plumbing” system together to carry out a cytoplasm, filled with a that conducts water and common function, such as watery fluid, bound by a dissolved mineral up the muscle tissue, connective membrane, and stems from the roots. tissue, and epithelial considered to be tissue. nonliving.

Day-to-Day Plans Time: 8 days The teacher should refer to the Teacher Resources section for specific information on teaching this lesson; in particular Lesson 4.1 Teacher Notes, Plant Glossary, Lesson 4.1 Materials List, and other support materials.

Day 1 – 2:  The teacher will present Concepts, Performance Objectives, Key Terms, and Essential Questions as a lesson overview.  The teacher will provide students a copy of Activity 4.1.1 Cell Parts and explain the procedures and expectations.  Students will work in pairs to complete Activity 4.1.1 Cell Parts.  The teacher will collect Activity 4.1.1 Cell Parts for grading after students complete the activity. Use Activity 4.1.1 Cell Parts Answer Key for assessment purposes. Day 3 – 4:  The teacher will provide students a copy of Project 4.1.2 Cell Analogy Collage explaining procedures and expectations.  The teacher will assign students an organelle.

The National Council for Agricultural Education – CASE – Copyright 2010 Plant – Unit 4 – Lesson 4.1 – Cells: Life’s Smallest Units – Page 6  Students will work individually to complete Project 4.1.2 Cell Analogy Collage.  The teacher will assess student work completed for Project 4.1.2 Cell Analogy Collage using the Project 4.1.2 Cell Analogy Collage Scoring Guide.  The teacher will provide students a copy of the Presentation Notes pages to be used throughout the presentation to record notes and reflections. These pages are to be added to the Agriscience Notebook.  The teacher will present PowerPoint® Types of Cells.  Students will take notes using the Presentation Notes pages provided. Day 5:  The teacher will provide students a copy of Activity 4.1.3 Examining Cell Structure and explain procedures and expectations.  Students will work individually to complete Activity 4.1.3 Examining Cell Structure. Day 6:  The teacher will lead students in a discussion to summarize the conclusions for Activity 4.1.3 Examining Cell Structure and collect completed activity sheets for grading.  The teacher will provide students a copy of the Presentation Notes pages to record notes and reflections.  The teacher will present PowerPoint® The Respiring Cell.  Students will take notes using the Presentation Notes pages provided.  The teacher will provide students a copy of Activity 4.1.4 Cellular Respiration LabQuest and discuss procedures for completion of the activity on Day 7. Day 7:  Students will work in pairs to complete Activity 4.1.4 Cellular Respiration LabQuest and submit for grading. Day 8:  The teacher will administer Lesson 4.1 Check for Understanding.  Students will complete Lesson 4.1 Check for Understanding and submit for grading.  The teacher will assess student work using Lesson 4.1 Check for Understanding Key.