Summary
Cells are the basic units of life, performing essential functions and containing various organelles. Cells — the smallest unit of living organisms. Example: Unicellular organisms consist of one cell. Prokaryote — cells without a true nucleus or membrane-bound organelles. Example: Bacteria. Eukaryote — cells with a true nucleus and membrane-bound organelles. Example: Plant and animal cells. Cell membrane — selectively permeable layer controlling substance movement. Example: Found in both plant and animal cells. Chloroplast — organelle containing chlorophyll for photosynthesis. Example: Present in plant cells. Mitochondrion — site of respiration, providing energy. Example: Found in active cells like muscle cells. Vacuole — storage organelle, large in plant cells. Example: Contains cell sap in plant cells. Nucleus — controls cell activities and contains DNA. Example: Present in both plant and animal cells.
Exam Tips
Key Definitions to Remember
- Cell: Basic unit of life
- Prokaryote: Cell without a true nucleus
- Eukaryote: Cell with a true nucleus
- Organelle: Specialized structure within a cell
Common Confusions
- Difference between prokaryote and eukaryote
- Function of chloroplast vs mitochondrion
Typical Exam Questions
- What is the function of the cell membrane? Controls movement of substances in and out of the cell
- How do plant and animal cells differ? Plant cells have a cell wall and chloroplasts; animal cells do not
- What is the role of mitochondria? Site of respiration and energy production
What Examiners Usually Test
- Differences between plant and animal cells
- Functions of various organelles
- Understanding of cell specialization and organization