What is difference between animals and plants in body movement
Movement in Plants
Plants, unlike animals, do not move from one place to another and respond to any external stimuli. Instead, they exhibit behaviours such as growing in a particular direction or opening and closing their leaves. There are two kinds of movements in plants, namely nastic movements and tropic movements (tropism). Nastic Movements These movements are response to stimuli coming from all directions.
For example, in tulip and crocus, change in temperature acts as the stimulus for the flowers to open and close. When the temperature rises they open, and when it drops they close.
Closing of the carnivorous venus fly-trap leaf when it captures a prey and folding of the Mimosa leaf when it is disturbed are also nastic movements. Folding of leaf of Mimosa is referred to as seismonasty movement.
Tropic Movements The response of an organism in the direction of a stimulus or away from it is called tropic movement or tropism. Tropic movements are of various types, in response to different stimuli.
When a young green plant receives light from only one direction, the stem grows towards the light source. Thus, the stem is said to be positively phototropic because the stem tip grows in the direction of light.
Geotropism is the tropic response of organisms to gravity. When a growing portion of the plant is placed horizontally, the stem tip grows away from the pull of gravity, while the root tip grows towards it. Thus, the stem is said to be negatively geotropic, while the root is positively geotropic.
The growth of roots towards soil moisture is called hydrotropism.
Thigmotropism is a growth in response to touch, e.g. tendrils on contact with a solid object, such as a twig, response curvature in that direction producing coiling around the object.
Locomotion or Movement in Animals
Animals exhibit three basic types of movements, namely amoeboid, ciliary and muscular.
Amoeba, an active unicellular animal, presses its cytoplasm against the cell membrane and produces a number of finger-like projections called pseudopodia. This type of locomotion is called amoeboid movement.
Euglena, which is pear-shaped or spindle-shaped, swims by means of a flagellum. The flagellum is held straight in front and the tip is rotated. This pulls the body of the organism forward through the water.
Paramecium moves with the help of tiny hair-like projections from the cell membrane called cilia. Cilia are arranged in rows and they lash through the water like tiny oars.
Multicellular organisms like Hydra have a strange looping or somersaulting motion. Hydra bends over, attaches its tentacles to the surface, swings the base over its mouth and attaches itself on the surface again. After loosening the tentacles, it repeats the process.
An earthworm uses its body muscles and setae to grip the ground so that the body can move forward by regular contractions and expansions of the muscles.
Insects such as grasshoppers and locusts have six-jointed legs and wings. The last pair is longer, stouter and more powerful to help them to hop.
Fishes use their fins against water to swim. Side fins help them steer. The fin at the back provides them balance.
Birds are the most common flying animals. They use their wings to fly and their two legs to walk or jump when they are not flying.