Can someone help me with these questions 3. Describe an insect\'s tracheal syste
ID: 191652 • Letter: C
Question
Can someone help me with these questions 3. Describe an insect's tracheal system, including its function and its structure. How does a tracheal system work for an insect that lives under water? 4. How would you expect the metabolic rate, and oxygen demand of an ectothermic, poikilothermic animal to vary with external temperature? 5. How would you expect the metabolic rate, and oxygen demand, of an endothermic animal to vary with external temperature? How does the availability of oxygen in water vary with water temperature? Using your answers to 4 and 6, suggest a hypothesis for whether you expect stoneflies to experience 6. 7. greater oxygen stress in cold water or warm water:Explanation / Answer
3. Let us study the trachel system of cockroach. Cockroaches are aerial breathers. The respiratory system of cockroach is well developed to compensate the poorly developed circulatory system.It consists of spiracles, tracheal trunks and trachioles.
In cockroach, the haemocoel contains a network of elastic, closed air tubes or tracheae. Three longitudinal tracheal trunks are present on each side of the abdominal cavity. The dorsal and ventral trunks are present near the middle line, while the lateral trunk is present on the lateral side of the abdominal cavity. Each lateral trunk is divided into two parts- the anterior part is present between mesothoracic, metathoracic and the first abdominal spiracle, while the posterior part extends from the second abdominal spiracle to the eighth abdominal spiracle. Each dorsal and ventral tracheal trunk originates from a trachea arising from the first abdominal spiracle. They extend upto the segmental branch arising from the eighth abdominal spiracle. Six trachea originate from each mesothoracic spiracle which supply to the head, prothorax and mesothorax. From the remaining spiracles three segmental trachea are given out on each side. The longitudinal trunks and segmental trachea are swollen at several places and are known as air sacs. Large trachea are internally supported by spiral ring of chitin called intima which prevents the tracheal tubes from collapsing. In addition, chitinous fibrils of 10 to 30 nm thickness and an epicuticle of lipoprotein, line the lumen of trachea.
Since there is no respiratory pigment in cockroach, so the blood of cockroach cannot transport oxygen. So the tracheal system is developed and functions to carry the air/ oxygen directly to the different tissues of the body.
For an insect that live under water, there is an outgrowth of trachea which are known as gills. It allows dissolved oxygen from the water to pass throgh the body of the insect. The different fanning movements of the gills keeps the insect in constant touch with water. It also acts as a jet propulsion system.