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:
It's like a transporter or a Post Office, sending stuff out
Explanation:
G o o g l e
and science class
When researchers examine these damaged nerves, they find that the myelin insulation is often gone and the axons are destroyed. These changes prevent nerves from transmitting messages properly.
A
Answer: here´s why
Explanation: Underneath the frozen upper layer, the water remains in its liquid form and does not freeze. Also, oxygen is trapped beneath the layer of ice. As a result, fish and other aquatic animals find it possible to live comfortably in the frozen lakes and ponds. If water is heated, its volume gradually decreases.