Grade 8: Life Science

Here is a comprehensive overview of the Grade 8 Life Science content, aligned with the British Columbia (BC) Curriculum.

In BC, the Grade 8 Life Science unit focuses on the levels of organization in living things, from cells to entire body systems, and the underlying principle of life: cell theory.

BC Grade 8 Science: Life Science Unit – Cells, Tissues, Organs, and Systems

This unit explores the question: “How are living things organized to carry out the functions of life?” It moves from the microscopic world of cells to the complex interactions of human body systems.

Overarching Big Ideas (for the Life Science Unit)

• Living things are made of cells, and life processes are carried out at the cellular level.

• The body is composed of cells, tissues, organs, and systems that must work together for an organism to function.

Core Components of the Grade 8 Life Science Unit

Part A: The Cell Theory and Microscopy

• Key Concepts: The fundamental unit of life, microscope use.

• Learning Goals:

  • State the three parts of the Cell Theory:

    1. All living things are composed of one or more cells.

    2. The cell is the basic unit of life.

    3. All cells come from pre-existing cells.

  • Safely and correctly use a compound light microscope to view plant and animal cells.

  • Prepare wet mount slides.

Part B: Cell Structure and Function

• Key Concepts: Organelles, plant vs. animal cells.

• Learning Goals:

  • Identify the structure and function of the main cell organelles:

    • Cell Membrane: Controls what enters and exits the cell.

    • Cytoplasm: Jelly-like substance where life processes occur.

    • Nucleus: The “control centre” containing DNA.

    • Mitochondria: The “powerhouse” where energy is released.

    • Vacuole: Stores water, nutrients, and waste.

    • Cell Wall: (Plant cells only) Provides rigid support and protection.

    • Chloroplasts: (Plant cells only) Where photosynthesis occurs.

  • Compare and contrast the structure of plant and animal cells.

Part C: Levels of Organization

• Key Concepts: The hierarchy of biological organization.

• Learning Goals:

  • Describe and explain the relationship between the following levels of organization in a multicellular organism:

    • Cell → Tissue → Organ → Organ System → Organism

  • Define each level and provide examples (e.g., muscle cell → muscle tissue → heart → circulatory system → human).

Part D: Human Body Systems

• Key Concepts: System functions and interactions.

• Learning Goals:

  • Describe the basic structure and function of several major human body systems, focusing on how they work together:

    • Digestive System: Breaks down food into nutrients that can be absorbed by cells.

    • Circulatory System: Transports nutrients, oxygen, and wastes to and from cells.

    • Respiratory System: Exchanges gases (oxygen and carbon dioxide) with the environment.

    • Musculoskeletal System: Provides structure, protection, and movement.

  • Explain the interaction between systems (e.g., the respiratory and circulatory systems work together to deliver oxygen to cells).

Part E: The Relationship between Microbes and Health

• Key Concepts: Pathogens, the immune system, and hygiene.

• Learning Goals:

  • Identify microbes (or microorganisms) as living things too small to be seen with the naked eye.

  • Differentiate between helpful microbes (e.g., gut bacteria, yeast for baking) and harmful microbes (pathogens like some bacteria and viruses that cause disease).

  • Describe how the body’s first line of defense (e.g., skin) and the immune system work to protect against pathogens.

  • Understand the importance of hygiene (e.g., handwashing) and vaccination in maintaining personal and public health.

Curricular Competencies in Action (The “Doing” of Science)

• Questioning and Predicting:

  • “How do the cells in our body get the energy they need from the food we eat?”

  • “Why are plant cells green, and animal cells are not?”

• Planning and Conducting:

  • Lab: Microscopic Examination of Cells. Students prepare and view slides of onion skin (plant cells) and their own cheek cells (animal cells), drawing and labeling what they see.

  • Investigation: Modeling Digestion. Use a plastic bag (stomach), vinegar (stomach acid), and a cracker to physically model the process of mechanical and chemical digestion.

• Processing and Analyzing Data and Information:

  • Analyze diagrams of different cell types to identify their organelles and infer their function.

  • Create a flowchart or concept map to trace the path of a oxygen molecule from the air to a muscle cell, identifying all the body systems involved.

• Evaluating:

  • Evaluate the impact of a lifestyle choice (e.g., diet, exercise, smoking) on the health and function of different body systems.

• Applying and Innovating:

  • Contribute to care for self, others, and community by creating a public health poster about the importance of handwashing in preventing the spread of pathogens.

• Communicating:

  • Create a “Wanted” poster for a specific pathogen, detailing its effects on the body and how the immune system fights it.

Sample Learning Standards from the BC Curriculum

• Content: “Explain the relationship between cells, tissues, organs, and organ systems.”

• Content: “Explain the basic functions of a human body system.”

• Content: “Identify the internal and external defence systems of the human body.”

• Curricular Competency: “Experience and interpret the local environment.” (e.g., connecting observations of whole organisms back to their cellular basis).

Key Connections to Other Grade 8 Science Units

• Connection to Chemistry: The process of digestion is a series of chemical reactions that break down food. Cellular respiration in the mitochondria is a key chemical process that releases energy.

• Connection to Physics: The circulatory system relies on principles of fluid dynamics and pressure. The musculoskeletal system uses levers (a simple machine) to create movement.

This unit provides a foundational understanding of biology that is essential for seeing the interconnectedness of life, from the microscopic processes inside a cell to the coordinated function of the human body.