Why do we now think that the Cenozoic radiation of monotremes had semiaquatic origins?
What will be an ideal response?
The modern platypus is a semiaquatic animal. We know of platypus skulls from the early Cenozoic that look very much like the modern form (implying a similar mode of life). However, molecular data suggest that the echidna (a terrestrial form) and the platypus diverged quite late, in the mid-Cenozoic. Thus, the echidna must have been derived from a platypus-like, semiaquatic form.
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All of the physiologically important atoms of the body readily form ions.
Answer the following statement true (T) or false (F)
About 3 liters of fluid are lost to the tissue spaces every 24 hours and are returned to the bloodstream as lymph
Indicate whether the statement is true or false
Explain the function of autonomic ganglia
A) They are part of visceral reflex arcs, and most of their activity is a direct reflex response, rather than responses to commands from the hypothalamus. B) They are part of the visceral motor neurons in peripheral ganglia. C) They are ganglionic neurons that innervate visceral effectors. D) They are upper motor neurons whose cell bodies lie within nuclei of the brain or the primary motor cortex. E) They are motor neurons within the central nervous system that are controlled by reflexes based in the spinal cord or brain.
The receptors responsible for detecting deep pressure and high-frequency vibration are
A. arrector pili corpuscles. B. lamellated corpuscles. C. tactile corpuscles. D. Krause bulbs. E. Ruffini corpuscles.