Answer: The following statements <em>comparing respiration in fish and in mammals</em> is correct:
- The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.
Explanation:
<u>Breathing </u>is the process by which living beings <em>exchange gases</em> with the external environment. It consists of the <u>entry of oxygen</u> into the body of a living being and the <u>exit of carbon dioxide</u> from it .
Active ventilation occurs if the animal produces the currents (of air or water) that flow to and from its respiratory membranes. It can be :
- Unidirectional. (air or water is pumped onto the respiratory membrane in only one direction).
- Bidirectional. (air or water is transported to the respiratory membrane and moves away from it through the same route like in the mammals).
Fresh water is any body of water with a low salt concentration. Organisms in fresh water various challenges which includes; Osmotic concentration such that fresh water is permanently dilute and most cells cannot function at this concentration of ions. Varying temperatures, variation in oxygen levels and reproduction and life cycle due to permanence of habitat and physiological difficulty of regulating osmotic concentration in larvae and juveniles.
Answer: A
Explanation:
"That's what evolution is all about: tiny changes in organisms of a species over a huge amount of time."