Observe an earthworm moving on soil in the garden. Gently lift it and place it on a piece of blotting or filter paper. Observe its movement now. In which of the above two surfaces do you find that the earthworm is able to move easily?
Observe a cockroach and identify its legs and wings. Try to know more about other parts of cockroach with the help of your teacher.
Observe a hen and crow. How do they move? Write about the similarities and dissimilarities found among them, in your note book.
Make a paper boat; put it in water and push it with narrow end pointing forward. Now hold the boat side way and push it into water from the broad side. What did you observe? In which process was it easy to move the boat? Have you noticed that the shape of a boat is somewhat like a fish?
Since snakes do not have legs, they use their muscles and their scales to move.
Fish have streamlined body structure which helps them to move smoothly with the flow of water. Muscles and fins on the body and the tail help to keep the balance.
• Cheetah can run 76 kilometrer per hour.
• Hippopotamus can run faster than a man.
• Cockroach is the fastest animal with 6 legs covering a metre per second.
• The fastest mammal, the Dolphin can swim upto 35 miles per hours.
Joints are the place where two bones meet or connect. Ligaments are short bands of tough fibrous connective tissues that function to connect one bone to another, forming the joint. Tendons are made of elastic tissues and they also play a key role in the functioning of joints.
Inflammation of joints is a condition that usually results either due to friction of articulating cartilage or due to lack of synovial fluid in the joint. During this condition, the person feels acute pain in joints particularly while moving joints. This disease is referred to as arthritis. Arthritis is however also caused due to the deposition of uric acid crystals in the joints.