"Identical twins come from a single fertilized egg, or zygote, that splits in two. Both halves contain the same DNA and eventually form two fetuses. But clones are formed in a different way. The first step in making a clone is to empty the DNA out of a fertilized egg".
-Google
Yes, it is possible that evolution occurs in this case.
At first, the new insecticide is effective against the boll weevil. Spraying the insecticide will kill the boll weevil in a way. The insecticide might attack boll weevil enzyme or any part of its organs.<span>
But some of them might have a mutation that renders the insecticide ineffective. The mutation probably happens to DNA that code the enzyme or protein that targeted by the insecticide, makes the insecticide completely ineffective.
The next spray will kill all old organism, leaving the new resistant organism in less competition area. This will allow the resistant organism to grow fast and eventually replace all the old organism in the area.</span>
Answer:
Whole brain death occurs when the BRAINSTEM ceases to function.
Explanation:
In the US, whole brain death = legal death. Most people consider that a person is brain dead when the cerebrum, or the higher brain, is dead because the person is not able to think or have control over his/her body, but legally you are brain dead only when the brainstem ceases to function. The brainstem is responsible for keeping you alive and performing the most basic bodily functions like breathing and keeping your heart beating. But once it fails, you are legally dead. Even if your body could still survive using a ventilator and other devices, your brain has ceased to work and you wouldn't be able to survive if you were unplugged.
Genetic variation allows for a greater chance of a population surviving. For example, if a plant species acquires a disease, without genetic variation the disease would just keep getting passed on to the next identical organism and the population would decline and eventually die. But genetic variation prevents that from happening, because you have so many other species in the ecosystem, and genetic variation is a product of sexual reproduction meaning that the offspring of the diseased plant has a possibility of not inheriting the disease.
