Although Having Evolved Independently, the Tracheal Tubes of Mammals and Insects

question 59

Multiple Choice

Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. The trachea of a mammal is supported by cartilage, and the tracheae of an insect are supported by chitin. What selective pressure most likely led to the convergent evolution of these respiratory structures?

• A) Both mammals and insects have similar oxygen needs.
• B) When air is the respiratory medium, there is a greater risk that the tracheal tubes will collapse.
• C) Insects and mammals both keep their internal temperature constant.
• D) A decrease in environmental carbon dioxide made structural support necessary.

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Definitions:

Lateral Corticospinal Tract

A key neural pathway located in the spinal cord, responsible for transmitting motor signals from the brain to muscles for voluntary movement.

Tectospinal Tract

A neural pathway involved in reflex movements of the head in response to visual and auditory stimuli.

Anterior Corticospinal Tract

A bundle of nerve fibers in the spinal cord involved in the voluntary movement of muscles, particularly influencing axial muscles.

Lateral Spinothalamic Tract

A neuron pathway within the spinal cord responsible for transmitting pain and temperature sensations to the brain.