Blood plasma is filtered in the____________.

A. Two haploid (n) cells; four haploid (n) cells: At the end of meiosis I, the result is two haploid cells, each with half the number of chromosomes of the original cell. At the end of meiosis II, these two haploid cells divide again to form a total of four haploid cells.

B. Two diploid (2n) cells; one haploid (n) cell: This option is incorrect because meiosis I produces two haploid cells, not diploid cells, and meiosis II produces four haploid cells, not one.

C. Two diploid (2n) cells; four haploid (n) cells: This option is incorrect because meiosis I does not produce diploid cells; it produces two haploid cells. At the end of meiosis II, the result is four haploid cells, which is correct, but the description of meiosis I is incorrect.

D. Two haploid (n) cells; one diploid (2n) cell: This is incorrect because meiosis I results in two haploid cells, and meiosis II results in four haploid cells, not one diploid cell.

A. The neural tube and yolk sac have formed: By 8 weeks, the neural tube and yolk sac have formed, but this is not the criterion for defining a fetus.

B. The amniotic cavity has formed: The formation of the amniotic cavity occurs earlier in development and is not the defining feature of a fetus.

C. All of the organ systems are present: By the end of 8 weeks, the basic structures of all major organ systems are present, which is why the embryo is referred to as a fetus from this point onwards.

D. The mesoderm has formed: The formation of the mesoderm occurs earlier and is not the defining factor for fetal status. By 8 weeks, more significant development, including the presence of organ systems, has occurred.