Answer: By studying the fossil record we can tell how long life has existed on Earth, and how different plants and animals are related to each other. Often we can work out how and where they lived, and use this information to find out about ancient environments. Fossils can tell us a lot about the past.
It prepares to fight danger or run from it. It identifies the primary source of danger.
Answer:
a layer or a series of layers of rock in the ground. ,
a level or class to which people are assigned according to their social status, education, or income.
Explanation:
This is because the traits like height, are influenced by environmental conditions around the individual. For example, there are two children born to same mother. But one is given best facilities, nutrition and care, whereas other one is brought up by a poor family, which hardly get good food to eat. His condition is much worse than the first case. In such a situation, the former child will grow up healthy and fit, and will have more height than the later one. Although, both got genes from same parent, but the environmental conditions influenced the expression of those genes differently.
