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1.) Hand movements and heartbeat classify the following and define the types?
The hand movements are a kind of voluntary movement because it can be controlled by our will.
The heartbeat is an involuntary movement it cannot be controlled by our will.
2.) Write a short note on skeletal muscle?
Skeletal muscle is also known as striated muscle attached to bones. They are cylindrical in shape. It helps in voluntary movement. They are dark and light striation.
3.) Assertion: muscles get exhausted and temporarily lose their power of contraction called muscle fatigue.
Reason 1: sufficient oxygen is available, lactic acid accumulates in the muscles as a result of aerobic respiration
Reason 2: increases acidity in muscles which in turn slows down the action of many enzymes associated with muscle contraction.
Options
a.) Reason 1and 2 both are correct
b.) Reason one is correct for the assertion reason 2 is incorrect
c.) Reason 2 is correct but reason 1 is incorrect
d.) Assertion is incorrect
Answer c
4.) Movement is also seen in plants. Explain the terms related to the movement of plants according to stimuli.
Plant movement when in the direction of stimuli, it is known as tropic movement
Sometimes the plant movement is not in the direction of stimuli hence it is called nastic movement.
Phototropism works on the stimuli of light both stem and roots show the movement stem towards the direction of stimuli and root against the direction of the stimuli.
Geotropism is movement according to gravity where roots move in the direction of the stimuli and stem against gravity.
Haptotropism is stimuli of support, when the stems move towards or around the object that causes the stimuli.
Chemotropism depends on the chemical produce which work as stimuli for example chemical produced by ovary helps in growth of pollen tube.
Hydrotropism is for both stem and root where roots move towards water and stem move away from the water.
5.) Case study
Megha saw an earthworm in her garden looking at it she had a question about the movement of earthworm as it has no skeleton. The other day she asked her teacher about the doubts she had. Try to answer the question
1.) What is the difference between movement and locomotion?
2.) Explain the locomotion in earthworm?
3.) What are the special parts in paramecium and euglena that help in movement?
1.) When displacement occurs in any part of the body it is known as movement. When entire body displacement takes place, it is called locomotion.
2.) Two types of muscles in earthworm, circular muscles and longitudinal muscles. Contraction and relaxation of muscles in earthworm leads to locomotion. Some parts like tiny projection out from the body called setae helps in locomotion.
3.) For paramecium and euglena special structures help in movement like cilia helps in movement of Paramecium, they are small protein filaments on the cell surface. In Euglena the flagellum helps in movement. They are long protein filaments.
6.) As the skeletal system helps in giving shape to the body. There may also be some disorders related to it enlist the disorders and explain any two of them?
The disorders associated with skeletal and muscular system are
Rheumatic Arthritis, Dislocation, Sprain, Osteoporosis, Muscular dystrophy
Rheumatic Arthritis
1.) Due to old age and infection in joints, degenerative changes and injuries. may lead to damage to cartilage.
2.) incapable of moving joints, leads to sever pain.
Dislocation
1.) Bones displacement in joints leads to ligament damage
2.) Difficulty in movements, leads to severe pain and oedema Sprain
1.) Severe pain and oedema leading to stretching or breaking of ligaments.
Osteoporosis
1.) The bones become brittle and causes fracture, may be due to deficiency of calcium, vitamin D.
2.) affects hip bone, vertebral column and wrist.
Muscular dystrophy
1.) Muscles become weak and lead to degeneration of muscles, affecting boys
