Vestigial they have eyes but they do not use them
Answer: light penetration
Explanation:
Substance abuse can stump knowledge growth (disable, prevent, or make it harder for someone to learn)
Substance abuse can also develop bad habits for when the abuser grows up.
Drink, smoking, etc.. at an early age can cause an individual to become prone to illness, cause incurable diseases (cancer)
ulcers, etc.
(Really though at any age that could happen)
Because a scientist uses artificial selection to produce a new type of cow, the new cows are considered to be a product of hybridization compared to their parents.
Answer:
B. Interneurons
Explanation:
The basic unit of the central nervous system is the neuron or the nerve cells. Billions of neurons allow the different parts of the body to communicate with each other via the brain and the spinal cord. A fatty material called myelin coats nerve cells to insulate them and to allow nerves to communicate quickly.