Plants and animals can be differentiated based on several characteristics. Let's go through each of these characteristics step by step:
1. Structure:
Plants are multicellular organisms with cell walls made of cellulose. They have a rigid structure provided by stems, leaves, and roots. Animals, on the other hand, have a more flexible structure without cell walls. They possess complex organ systems and are composed of various types of tissues.
2. Locomotion:
Most plants are sessile, meaning they are rooted in one place and do not have the ability to move. They rely on external agents like wind or other organisms to disperse their reproductive structures (pollens, seeds, spores). In contrast, animals are generally mobile and capable of moving from one place to another. They possess muscles and specialized structures for locomotion.
3. Irritability:
Irritability refers to the ability of an organism to respond to stimuli from its environment. Plants exhibit a simple form of irritability called tropism, where they respond to light (phototropism), gravity (gravitropism), or touch (thigmotropism). Animals, on the other hand, possess complex nervous systems that allow them to respond to various stimuli quickly.
4. Metabolic Process:
Plants are autotrophs, which means they produce their own food through the process of photosynthesis. They use sunlight, water, and carbon dioxide to produce glucose and oxygen. Animals, however, are heterotrophs, meaning they obtain their energy by consuming other organisms. They ingest food and use complex digestive systems to break it down and extract nutrients.
5. Waste Products:
During metabolic processes, plants produce oxygen as a waste product of photosynthesis. They also produce small amounts of waste in the form of resins, gums, and oils. Animals, on the other hand, produce carbon dioxide and various nitrogenous wastes, such as urea or ammonia, as byproducts of their metabolism.
6. Growth and Development:
Plants exhibit indeterminate growth, meaning they can continue to grow throughout their lives. They have meristems (regions of cell division) that allow for the continual production of new cells, resulting in growth. Animals, on the other hand, generally exhibit determinate growth, meaning they reach a fixed size once they reach adulthood. They have a limited number of cells and organs that grow during development until they reach their final size.
7. Outer Covering:
Plants have external coverings, such as leaves and stems, made of cuticles and epidermis, providing protection against environmental factors. Animals typically have a wide range of outer coverings, including skin, fur, feathers, scales, or exoskeletons. These coverings serve various purposes like protection, insulation, or sensory perception.
8. Food Making Processes:
As mentioned earlier, plants are capable of making their own food through photosynthesis, using light energy to convert water and carbon dioxide into glucose. Animals, being heterotrophs, cannot produce their own food. They obtain necessary nutrients by feeding on plants, other animals, or both, utilizing different processes of ingestion and digestion.
These are the key differences between plants and animals based on the mentioned characteristics.