The first three are the same as those found in DNA, but in RNA thymine is replaced by uracil as the base complementary to adenine. This base is also a pyrimidine and is very similar to thymine. Uracil is energetically less expensive to produce than thymine, which may account for its use in RNA.
it led to a study of how to induce cancer cells to divide more rapidly
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.
Answer:
Homologous structures provide evidence for common ancestry
