Question

Which of the following is true for tracheae?

• A. Are typically found in molluscs
• B. Are highly vascular
• C. Branch and extend to all the cells
• D. Are characteristics of many mammals

Answer 1

The correct option is C Branch and extend to all the cells

Insects, and some other invertebrates, exchange oxygen and carbon dioxide between their tissues and the air by a system of air-filled vasculat tubes called tracheae. Tracheae open to the outside through small holes called spiracles. Insects have an impermeable exoskeleton and internal gas exchange system in order to prevent water loss (dessication). This is an adaptation to their terrestrial (land) lifestyle. These tracheae are highly branched helping to increase the Surface area : volume ratio available for gas exchange.

So, the correct option is 'C'.