Features of Organisms

Summary and Exam Tips for Features of Organisms

Features of Organisms is a subtopic of Key Concepts in Biology, which falls under the subject Biology in the Edexcel GCSE curriculum. This topic explores the classification and characteristics of living organisms, focusing on eukaryotic and prokaryotic organisms, specialized cells, microscopy, and using units.

• Eukaryotic Organisms: These are classified into five kingdoms: Animals, Plants, Fungi, Protoctista, and Prokaryotes. Eukaryotic cells contain cytoplasm, a cell membrane, and DNA. Animals are multicellular, lack cell walls, and feed on organic substances. Plants are also multicellular, have chloroplasts, and perform photosynthesis. Fungi have cell walls not made of cellulose and feed saprophytically or parasitically. Protoctista can be unicellular or multicellular, with some capable of photosynthesis.

• Prokaryotic Organisms: These are often unicellular with cell walls not made of cellulose, lacking a nucleus and mitochondria.

• Specialized Cells: Cells like sperm, egg, and ciliated epithelial cells have evolved specific traits for reproduction and protection.

• Microscopy: Electron microscopes offer high resolution and magnification but are expensive, while light microscopes are more cost-effective. Proper slide preparation is crucial for accurate observation.

• Using Units: Understanding unit conversion and magnification calculations is essential. For example, $1 \, \text{mm} = 1000 \, \mu\text{m}$.

Exam Tips

• Understand Kingdom Characteristics: Familiarize yourself with the main features of each kingdom, especially differences in cell structure and nutrition methods.

• Specialized Cells Functions: Remember the specific functions and structures of specialized cells like sperm and egg cells.

• Microscopy Techniques: Practice preparing slides and understand the differences between electron and light microscopes.

• Unit Conversion and Magnification: Master unit conversions and the magnification formula. Always ensure units are consistent when performing calculations.

• Exam Strategy: Pay close attention to the units provided in questions to avoid losing marks, and practice calculating the size of subcellular structures.