Traits are determined by genes, and also they are determined by the interaction with the environment with genes. And remember that genes are the messages in our DNA that define individual characteristics. So the trait is the manifestation of the product of a gene that is coded for by the DNA.
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Fertility drugs contain FSH and LH, which stimulate eggs to mature in the ovary. Fertility treatments increase a woman's chance of becoming pregnant, although the treatment may not always work. On the other hand, because the treatment boosts the production of mature eggs, it increases the chance of twins or triplets.
He brought back galapagos turtles and finches
Neurons, act as the communicators of the nervous system. Neurons receive information, integrate it, and pass it along. They communicate with one another, with cells in the sensory organs, and with muscles and glands.
Information was taken from: http://www.sparknotes.com/psychology/psych101/thebrain/section2/
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Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids, and gases from water. The goal is to produce water fit for specific purposes.