Answer:
The answer is the mutations within the genetic code.
Step-by-step explanation:
Natural selection is one of the basic mechanisms of evolution by which species adapt to their environment in order to increase their chance of survival and reproduction. In natural selection, genotype variations that will increase the chance of survival and reproduction of some organism are preserved and will be inherited. But, the sources of this genotype variations are not changes in the environment, nor response to the stress, but the mutations in the genome of the organism. If a mutation is not lethal, it could remain in the population, increasing the variation is some traits.
Hope this helps !!!!!!!!!!!!!!!!!
Answer:
first one
Step-by-step explanation:
Since it is given that Boris takes x minutes to run 5 miles it means that Boris' speed will be given as: 
.
Now, if Dylan runs slower than Boris and takes 12 more minutes to complete the 5 miles run, then that would mean that Dylan takes (x+12) minutes to complete the same run.
In this case we can see the Dylan's speed will be 
.
Thus, the denominator represents the time Dylan takes to run 5 miles if he takes 12 minutes more than Boris.
Therefore, out of the given options, the second option is the correct option.
Answer:
x = 27
Step-by-step explanation:
The angle at any point on a straight line is 180 degrees.
The middle line over there is creating a right angle which is 90 degrees.
This must mean that both sides are 90 degrees.
3x+9 = 90
3x = 81
x = 27
