1. Movement: Linnaeus observed that plants were stationary while animals moved freely. This was a primary distinction for him.
2. Nutrition: Linnaeus recognized that plants produced their own food through photosynthesis, while animals consumed other organisms for sustenance.
3. Reproduction: Linnaeus noted that plants reproduced sexually through flowers and seeds, while animals reproduced sexually through mating and offspring. However, it's important to note that this wasn't entirely accurate. Some plants reproduce asexually, and some animals reproduce asexually as well.
4. Structure: Linnaeus observed that plants had a rigid, often woody structure with leaves, stems, and roots, while animals had softer tissues and a more complex internal structure.
It's crucial to understand that Linnaeus's system was based on observable characteristics. While it was a significant advancement for its time, it doesn't fully reflect the complexity of life. Today, we use a more sophisticated system based on evolutionary relationships and genetic information.
However, Linnaeus's work laid the foundation for modern taxonomy, and his system of binomial nomenclature (using two names, genus and species) is still used today.