Chapter Notes and Summary
• Respiration is highly important for life of all living organisms.
• oxygen inhaled by us, helps to breakdown glucose into water and carbon dioxide. In this process, energy is released.
• breakdown of glucose takes place in cells of an organism (cellular respiration).
• When food is broken down by using oxygen, it is mentioned as ‘Aerobic respiration’. If breakdown takes place independent of oxygen, then it is referred to as anaerobic respiration.
• During heavy exercise, when supply of oxygen to our muscles is less than enough, food breakdown occurs through anaerobic respiration.
• Breathing is one part of process of respiration during which an organism takes in oxygen rich air and releases air rich in carbon dioxide. respiratory organs for interchange of gases vary from one organism to another.
• During inhalation, our lungs expand first and then return to their original position as air passes out during exhalation.
• breathing rate is raised by increased physical activity.
• Among animals like cat, cow, dog and buffalo, breathing process and respiratory organs are like those in us.
• Amongst earthworms, exchange of gases takes place through moist skin. In a fish, it occurs through gills, with insects, it is through trachea.
• In a plant, roots inhale air found in soil. Leaves possess small little pores known as ‘stomata’ through which they exchange gases. breakdown of glucose among plant cells is just like all other living beings.