Study Notes
Cells are the basic units of life, with distinct structures and functions in both animal and plant cells. Specialized cells have unique adaptations to perform specific roles.
- Cell Membrane — Envelops the cell contents and controls what enters and leaves the cell. Example: Selectively permeable, allowing only some molecules through.
- Nucleus — Contains DNA genes which code for proteins controlling cell activities. Example: Acts as the control center of the cell.
- Cytoplasm — A liquid part of the cell where cellular chemical reactions occur. Example: Fills the volume of the cell.
- Mitochondrion — Organelle for aerobic respiration, providing energy for the cell. Example: Cells with high metabolism have more mitochondria.
- Ribosomes — Structures for protein synthesis, found free in cytoplasm or on endoplasmic reticulum. Example: Site of protein synthesis.
- Vesicles — Transport substances within the cell. Example: Safely move materials from one part of the cell to another.
- Cell Wall — Supports and strengthens plant cells, made from cellulose. Example: Allows plant cells to be turgid without bursting.
- Sap Vacuole — Stores water and sugars in plant cells. Example: Contains cell sap.
- Chloroplast — Organelle for photosynthesis in plant cells. Example: Converts light energy into chemical energy.
- Red Blood Cell — Transports oxygen, lacks a nucleus to hold more hemoglobin. Example: Biconcave shape for maximum oxygen diffusion.
- Ciliated Cell — Moves mucus in the trachea and bronchi. Example: Cilia sweep mucus along respiratory tubes.
- Sperm Cell — Involved in fertilization and reproduction. Example: Tail enables swimming to fertilize the egg.
- Egg Cell — Contains nutrients for embryo growth. Example: Cell membrane changes to prevent multiple sperm entry.
- Nerve Cell — Conducts impulses with long extensions. Example: Axon covered with a fatty sheath for insulation.
- Root Hair Cell — Absorbs water and minerals from soil. Example: Increased surface area for absorption.
- Xylem Vessel — Conducts water and supports the plant. Example: Thickened walls with lignin for support.
- Palisade Mesophyll Cell — Performs photosynthesis. Example: Contains many chloroplasts for maximum photosynthesis.
Exam Tips
Key Definitions to Remember
- Cell Membrane: Selectively permeable barrier of the cell
- Nucleus: Control center containing DNA
- Cytoplasm: Site of chemical reactions in the cell
- Mitochondrion: Organelle for energy production
- Ribosomes: Site of protein synthesis
- Cell Wall: Provides support in plant cells
- Chloroplast: Site of photosynthesis in plant cells
Common Confusions
- Confusing the functions of mitochondria and chloroplasts
- Mixing up cell wall and cell membrane functions
Typical Exam Questions
- What is the function of the mitochondrion? Provides energy through aerobic respiration
- How do plant and animal cells differ? Plant cells have a cell wall, chloroplasts, and a large sap vacuole
- What adaptations do red blood cells have? Lack of nucleus, biconcave shape, and flexibility
What Examiners Usually Test
- Ability to label diagrams of plant and animal cells
- Differences between plant and animal cells
- Functions and adaptations of specialized cells
- Understanding of cell organelle functions