They have valves that give it a pumping effect so that it can pump blood
I think the best answer from the choices would be the first option. Icebergs float in the ocean since i<span>cebergs are composed of freshwater and freshwater is less dense then salt water. The ocean contains salts which contributes to its density which most likely would be higher with that of an iceberg.</span>
Answer:
The correct option is A. they evolved from land mammals.
Explanation:
Evolution can be described as a process through which organisms in a species change over a period of time due to the natural selection of the environment. Those organisms that have many similarities in their functions or structures are considered closer to one another and have the same common ancestors.
The properties mentioned in the question about cetaceans resembles the properties of land mammals. For example, cetaceans lack gills and breathe air. Land mammals also do not have gills and need to respire for living. The cetaceans have fin bones which are similar to the limb bones in the land mammals. Hence, these observations show that cetaceas have evolved from land mammals.
Answer:
None of the above
Explanation:
Diversifying is the right kind of selection
