Answer:
Precipitation, water availability, sunlight, and temperature are all abiotic factors. Deserts are characterized by their lack of rainfall. Although we usually think of deserts as being hot, some deserts can be cold too. Biotic factors are all the living things in an ecosystem. So organisms such as cacti and the kangaroo rat.
<span>The crust (sedimentary/igneous/metamorphic rocks), the mantle (oxygen, silicon, magnesium, iron) , inner core (solid iron and nickel) and outer core (liquid iron and nickel). </span>
A) Molecular clocks help to measure the number of changes and mutations which accumulate in the gene sequence of different species over a period of time.
B)It is based on the fact that genetic mutations although random, occur at a relatively constant rate. Evolutionary biologists use this information to deduce how species evolve and determine when two species diverged on the evolutionary time line.
It is useful in the study of variations in selective forces.
It also facilitates establishing the dates of phylogenetic events including those not documented by fossils.
The molecular clock technique is an important tool in molecular systematics. It helps to determine the correct scientific classification of organisms by deriving information from molecular genetics.
Hope this helped :) please mark brainliest
