Grade 8 — Science: Unicellular and Multicellular Organisms: Cells, Tissues and Systems

Overview

Using print and electronic resources, students research the difference between unicellular and multicellular organisms, and determine the structural and functional relationship among cells, tissues, organs, and systems. Students create interactive representations, or compose analogies that identify and describe the structural and functional relationship of cells, tissues, organs, and systems.

Activate

Students brainstorm examples of single-purpose and multipurpose objects (e.g., CD player vs. home entertainment system). Students describe the advantages and disadvantages of each. Students identify individual components of multipurpose objects, describe their structural and functional relationships and draw possible parallels with human body systems. They formulate questions to investigate the subject [Plan and Question].

Students use print and electronic resources to find images of various types of plant and animal cells (unicellular and multicellular). [Gather and Make Sense] Students brainstorm various types of cells found in a multicellular organism (e.g., blood, nerve, muscle, bone, skin cells, etc.). Students list the main function of each type of cell; they predict and describe the type of structure that cell has to enable it to carry out this function. [Gather and Make Sense, Plan and Question] Using painting or drawing tools, students illustrate the structure of various types of cells and describe their functional relationships with other cells in a multicellular organism. [Gather and Make Sense] Students compare illustrations with peers and discuss similarities and differences between various living things.

Teacher Tip:
Use a Gallery Walk of computer monitors or an electronic projection system for viewing illustrations. [Communicate]

Acquire

Using print and electronic resources, students research and record examples of specialized cells and tissues. [Gather and Make Sense] They look for information that supports their previous predictions and modify them as needed [Plan and Question, Gather and Make Sense]. Using appropriate software, students describe the structural and functional relationship among the cells, tissues, organs, and body systems and the reason cells and tissues are specialized in multicellular organisms. [Gather and Make Sense]

Working in collaborative groups, students brainstorm the needs of living things (e.g., food, oxygen, water, etc.). [Collaborate] Using appropriate software to construct a chart, students list the needs and identify the systems responsible for fulfilling each need (e.g., digestive system, respiratory system, circulatory system, etc.). [Gather and Make Sense] Students list the organs and the characteristics of the structure and function of the tissues and cells for each system. When necessary, students evaluate their original inquiry, come up with additional questions and incorporate new information with their prior knowledge [Plan and Question, Gather and Make Sense].

Teacher Tip:
Teachers ensure students understand that cell specialization is necessary to ensure access to the external environment. For more information on Brainstorming, please see p. 12 K to 8 ELA Strategies.

In collaborative groups, using print and electronic resources, students research and compare how systems and structures in unicellular and multicellular organisms (e.g., frog, paramecium, plant, human, invertebrate) perform various functions (e.g., movement, food intake, digestion, gas exchange). [Collaborate, Gather and Make Sense] Using suitable software, students construct a table or chart  to illustrate the differences among the systems. [Gather and Make Sense, Produce to Show Understanding]

Using print and electronic resources, collaborative groups of students research  a specific body system (e.g., circulatory, muscular, digestive, etc.). [Collaborate, Gather and Make Sense] Using suitable software, students create a flow chart of all related organs, tissues, and cells for that body system and describe the function that each system performs and the specialization of the cells and tissues. [Gather and Make Sense] Students share completed flow charts with peers to identify similarities, differences and the need to add or clarify information [Gather and Make Sense].

Apply

Collaborative groups of students create a Unicellular and Multicellular Organism representation. [Collaborate, Produce to Show Understanding] They begin with an image of a living thing (e.g., unicellular organism, invertebrate, vertebrate, plant, etc.) as the first slide. They create links from the parts of the organism that perform various functions (e.g., movement, food intake, digestion, gas exchange) to additional slides that identify and describe the cells, tissues, and organs responsible for each function.

Suggestions for Assessment
Student describes the similarities and differences between two living things (e.g., tree, rabbit) of the structures and systems and the related cells, tissues and organs responsible for various functions (e.g., gas exchange, food intake, etc.).
Observation: Observe interaction of students in collaborative groups as they prepare their representations. Look for leadership as well as problem solving and perseverance through ICT challenges. [Collaborate, Motivation and Confidence]

Each group makes a class presentation of its representation .[Communicate] Students compare the similarities and differences of structures and systems in different groups of living things. Groups assess each other’s contributions in order to enhance their representations. [Reflect, Produce to Show Understanding]

Suggestions for Assessment
Students assess each other's representations and give feedback to clarify and enhance their representations.