Despite numerous similarities between plants and animals they show many differences.
Differences between plants and animals:
Most plants are green in color. They contain a green pigment called chlorophyll which helps the plant to prepare food by the process of photosynthesis. Green plants pick up water and salts from the soil and carbon dioxide from the air and prepare their food (glucose) in the presence of sunlight. Green plants are therefore said to the ‘autotrophic’ where ‘auto’ means self and ‘troph’ refers to food.
Since animals lack chlorophyll they are incapable of manufacturing their own food. They have to depend directly or indirectly on plants for food. Animals are thus heterotrophic where ‘hetero’ means different.
Plants remain fixed to the ground and do not move from one place to another except some lower plants like chlamydomonas, and volvox which freely move about in water. In contrast, most animals move freely move about in water. In contrast, most animals move freely from place to place. However, some animals like corals, sponges and sea anemones do not move about they remain fixed at a place.
3. Response to stimuli:
If someone pricks your finger with a pin, you immediately withdraw your hand. If you touch a snail, it immediately hides inside its shell. If you touch a snail, it immediately hides inside its shell. On the other hand, if you touch a plant or prick its leaf with a pin, it shows no response. However, if you keep a plant in a closed box with an open window on one side, you would notice that the plant tends to grow towards the window.
Thus, animals show a quicker and specific response whereas plants show very slow responses. This is because animals have a well-developed nervous system which helps them to show appropriate response to any change in environment (a stimulus).
Plants grow throughout their lives while growth in animals stops after a certain age. Growth is restricted to certain places in plants like the tip of the root and the tip of the shoot whereas the whole body grows uniformly in animals.
Plants reproduce mainly by producing seeds or spores. Flowering plants like sunflower and mustard reproduce by seeds. Plants like sterns produce spores for reproduction. Some plants however also reproduce through leaves, stems and roots. In Bryophyllum, several tiny plants are produced on the leaf margin. Many plants like ginger, potato and gloriously reproduce by means of underground stems.
Animals on the other hand reproduce by giving birth to babies or lying eggs or just dividing their body into two or more parts. For example, human beings, dogs and cows give birth to babies while birds, snakes and fishes lay eggs. Single-celled animals like amoeba and paramecium reproduce by just splitting their body into two parts.
6. Cell structure:
All living organisms are made up of cells. But, there are striking differences between a plant cell and an animal cell.
- All plant cells are surrounded by a rigid cell wall made of cellulose. The cell wall is present outside the cell membrane and provides additional support to the cell. An animal cell lacks the cell wall and is surrounded by the cell membrane.
- Plant cells possess certain special bodies called chloroplasts which contain green coloring pigment called chlorophyll.
- Plant cells generally have a large vacuole that occupies a major portion of the cell, whereas in animals cells vacuoles are either absent or few and smaller in size, if present.