<span>A nerve is a bundled unit of nerve fibers located in the ide peripheral nervous system of the brain and spinal cord, connecting various parts of the body. These are the axons and are cable-like bundles which provide a way for all the electrochemical signals. They are of 3 types: afferent, efferent and mixed nerves. </span>
B. producer because most autotrophs are green plants use light for energy.
Ecologists make models to gain insight into complex phenomena such as the effects of global warming on ecosystems.
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Answer:
Polygenic traits are controlled by a number of separate genes.
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Answer:
B. The father did not contribute a sex chromosome to his daughter due to nondisjunction of the sex chromosomes. The daughter is XO and her only X chromosome came from her mother, who was a carrier.
A.The mother's X chromosomes failed to separate during meiosis, and the daughter inherited two X chromosomes with the Lesch-Nyhan mutation. The father contributed no sex chromosomes.
Explanation:
As seen in the question above, a little girl was diagnosed with Lesch-Nyhan syndrome, which is an X-linked recessive condition caused by a mutation in the HPRT1 gene responsible for purine metabolism.
The little girl's parents do not have the syndrome, and no one in the little girl's paternal family presented this syndrome, however, we know that the maternal grandfather of the little girl's mother had the syndrome, which means that it was the mother's genetic material that contributed to the development of the syndrome in the little girl. This was because the little girl did not receive any X chromosomes from her father, but she inherited the two X chromosomes from her mother that coded for the Lesch-Nyhan mutation. This happened because the mother's X chromosome disjuction did not occur during meiosis I.
As shown above, the father did not contribute any sex chromosomes to his daughter, which means that the daughter is XO and her only X chromosome came from her mother, who was a carrier.
