Describe the structure of representative vertebrate hearts from fish through mammals. Briefly explain the circulation
pattern supported by one type of non-mammalian vertebrate heart. What will be an ideal response?
As shown in Fig. 44-8 (page 939), the fish heart has a single atrium and a single ventricle,
and consequently, fish have a single circuit of blood flow. The amphibian heart has two atria
and one ventricle. In amphibians, blood flows in a double circuit – a pulmonary circuit and a
systemic circuit – but there is some mixing of oxygen-rich and oxygen-poor blood in the
ventricle. The nonavian reptilian heart has two atria and two ventricles, and blood flows in a
double circuit as well. In these animals the wall between the ventricles is incomplete, and
consequently there is some mixing of blood. Birds and mammals also have two atria and two
ventricles, but the wall between the ventricles is complete, and thus there is no mixing of
oxygen-rich and oxygen-poor blood. These animals have a double circuit of blood flow as
well.
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By definition, for osmosis to occur, the membrane separating two compartments must be permeable to the dissolved solute
a. True b. False
The difference between an ecosystem and a community is that the ecosystem has something a community does not have; the ecosystem has
A. producers. B. consumers. C. nonliving parts. D. interacting species.
Structures in plants that produce the gametes are called
What will be an ideal response?