Insects in flight have a higher metabolic rate than they do at rest and consume 10 to 200 times more O2 than when they are at rest. Despite this high energy expenditure, insects are able to generate extra energy while flying. What mechanism facilitates this?

When insects fly, they expend more energy and consume more oxygen as compared to their state of rest. Insects have a tubular breathing system called tracheae, instead of lungs. The action of flight muscles pumps air through the trachea. This is how they generate extra energy while flying.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

you must remain stopped until the stop signal is retracted and the red lights are turned off. approaching traffic in the opposite roadway of a divided highway shall not be required to stop, even if the school bus has the stop-arm extended and the alternately flashing warning signal lamps on.