Cell Specialization Gr. 7 Science

The Big Idea Plants and animals, including humans, are made of specialized cells, tissues, and organs that are organized into systems.

Remember... Cell  Tissue  Organ  Organ System  Organism

Specialization is the adaptation of a cell to perform a specific function. In most multicellular organisms, as their structures and life functions become more complex, their cells become more and more specialized for performing particular activities.

Brainstorm What different types of cells in the body can you think of? What functions does each of those cells perform?

Blood cells- red and white Muscle cells Brain cells Bone cells Liver cells Skin cells Eye cells Sex cells (egg and sperm)

Warm-up What do you think the phrase “form follows function” means? How does it relate to the human body? The shape (form) that a cell has allows it to do its job (function) 1. Research the function of the 6 different types of cells on your “Building Blocks” worksheet and describe the function of the cell in the third column. 2. Then look at the shape (form) of that cell and infer how it helps the cell perform its job (function)

White Blood Cell The job of the WBC is to fight disease causing organisms in the body. The shape of the WBC allows it to surround and engulf disease causing bacteria and then digest it. Nerve Cell Job: Send messages throughout the body Shape allows the dendrites to receive message, axon allows message to travel along it, axon endings transmits the message to the next nerve cell. They are lined up end to end in the body in a network (almost like telephone lines)

Bone cell Job: Support the body Shape: thick and compact which makes it strong enough to support the body of an organism Muscle Cell Job: Helps the body move. Muscles pull on the bones pushing them up or down. Shape: Strands of cells that can contract and relax to cause movement by pushing and pulling on the bones.

Epithelial Cell Function: Line, cover, and protect the organs and systems of the body. Shape: Flat cells that can stack one on top of another to create lining Red Blood Cell Function: Carry oxygen and carbon dioxide through the body Shape: “Donut” shape that allows it to carry oxygen gas to all tissues of the body. Contains a protein hemoglobin that chemically bonds (connects) to oxygen

Warm-up “The specialization of cells serves the operation of the organs and the organs serve the needs of the cell.” Explain the meaning of the quote above in your answer please include: 1. Your understanding of the words “specialization of cells” 2. The definition of organ 3. Specific examples of the meaning of the quoted statement.

One or Many??? A single-celled organism is called UNICELLULAR Examples: bacteria, algae (plant), yeasts (fungi) These organisms perform ALL of their functions in ONLY ONE CELL!!!

Multicellular organisms are made up of MANY cells. These organisms have cell specialization different types of cells for different jobs/purposes. As cells specialize, only DNA related to the functions of a particular cell remains active

Tissue – a group of cells that are structurally similar and perform the same function Ex. muscle, nerve, blood

Muscle Produces force and motion Tissues are specialized for contraction

Nervous Controls body function and movement Carries electrical messages back and forth from the brain to the body. Ex: Brain cells, spinal cord, throughout the body (ear, nose, tongue, eye, fingers, etc.)

Connective Connects/binds different tissues, organs, and organ systems together Provides support to the body Ex. tendons, ligaments, bone, cartilage, blood vessels, and fat

Epithelial Consists of layers that cover and protects body surfaces and lines body cavities Ex: Skin, covers the liver, lines the digestive system

Muscle Tissue Skeletal, Cardiac, Smooth

Skeletal Muscle Voluntary motion Parallel striations Majority of muscle

Cardiac Muscle Found only in heart Involuntary Branched striations

Smooth Muscle Involuntary movement No striations Found in hollow organs (intestines, blood vessels, etc.)

Warm-up Define connective tissue and give 2 examples of connective tissue and their functions. Connects/binds different tissues, organs, and organ systems together Provides support to the body Ex. tendons, ligaments, bone, cartilage, blood vessels, and fat Tendons connect muscles to bone Ligaments connect bone to bone in a moveable joint. Bone connects the body together