This lesson explains the major kinds of cells (prokaryotic vs eukaryotic), differences between plant and animal cells, specialized cell types in multicellular organisms, and the role of stem cells. It uses analogies and tables to connect structure with function and includes practice questions, flashcards, concept maps, and varied exercises to reinforce understanding.
Types of Cells — The Wild Neighborhood Inside You Imagine your body as a bustling city. Every building, road, and worker has a job. Cells are the tiny citizens, each with its own profession and address. You already met the star law of the cellular universe in the previous lesson: Cell Theory — t...
Why types of cells matter (quick recap from cell theory) Because organisms can be a single cell or a trillion, cells specialize. The Cell Theory says life is cellular; the diversity of life comes from diversity of cell types. Different cell types are like different tools in a toolbox: you would no...
Big picture split: Prokaryotic vs Eukaryotic This is the first major fork in the road. Prokaryotic cells (short and efficient) Who: Bacteria and Archaea. Size: Usually smaller (0.1 5 micrometres). Key features: No nucleus; DNA floats in the cytoplasm in a region called the nucleoid. Few me...
Eukaryotic cells (fancy and organized) Who: Animals, plants, fungi, and protists. Size: Usually larger (10 100 micrometres). Key features: Distinct nucleus holding DNA, many membrane-bound organelles like mitochondria and chloroplasts (in plants). Example: A human cheek cell — full of nucleu...
Plant vs Animal cells — not the same, not even close friends Within eukaryotes, plant and animal cells diverge because plants have photosynthesis to worry about. Plant cells have a rigid cell wall, chloroplasts (for photosynthesis), and a large central vacuole for storage and support. Animal c...
Specialized cells — when cells pick a major and never look back In multicellular organisms, cells become specialists. This is called differentiation. They follow genetic instructions and local signals to become nerve cells, muscle cells, and so on. Here are the headline acts. Nerve cells (neuron...
Stem cells — the undecided teenagers of biology Stem cells are undifferentiated cells that can become many types. They are essential for growth and repair. Embryonic stem cells can become almost any cell type. Adult stem cells are more limited but important for healing (like in bone marrow mak...
Mini-mnemonic to remember major splits P-P: Prokaryote = Plain (no nucleus) E-E: Eukaryote = Elegant (nucleus & organelles) Plants: Photosynthesis + wall Animals: Agile + no wall Keep it silly — it helps memory. Why people get confused (and how to not be one of them) Confusion 1: All ce...
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