Summary
The organisation of the organism involves understanding the structure and function of cells, tissues, organs, and systems in living organisms.
- Cell wall — a rigid layer that provides structural support and protection to plant cells. Example: Found in plant cells but not in animal cells.
- Chromosome — a structure within the nucleus that contains DNA. Example: Smaller than a white blood cell and part of the nucleus.
- Xylem — a tissue made of vessels that transport water and minerals in plants. Example: Collectively forms a tissue, not a single cell or organ.
- Cell membrane — a structure that controls the movement of substances in and out of the cell. Example: Present in both plant and animal cells.
- Mitochondrion — an organelle where aerobic respiration occurs, releasing energy. Example: Known as the powerhouse of the cell.
- Ribosomes — structures responsible for protein synthesis. Example: Involved in producing proteins like insulin.
- Root hair cell — a plant cell with a large surface area for water absorption. Example: Does not lose water by transpiration.
Exam Tips
Key Definitions to Remember
- Cell wall: Provides structural support to plant cells.
- Chromosome: Contains genetic information within the nucleus.
- Xylem: A tissue that transports water in plants.
- Cell membrane: Regulates entry and exit of substances in cells.
- Mitochondrion: Site of energy production in cells.
- Ribosomes: Sites of protein synthesis.
Common Confusions
- Confusing cell wall with cell membrane functions.
- Mistaking xylem for an organ instead of a tissue.
- Assuming all cells have chloroplasts, which are only in plant cells.
Typical Exam Questions
- What is the function of the cell wall? Provides structural support to plant cells.
- How do xylem vessels function in plants? They transport water and minerals throughout the plant.
- What is the role of mitochondria in cells? They produce energy through aerobic respiration.
What Examiners Usually Test
- Differences between plant and animal cell structures.
- Functions of various cell organelles.
- Understanding of cell, tissue, organ, and system hierarchy.