Meiosis and Gametogenesis (2C) Practice Test

An investigator isolates human oocytes at different times after the LH surge and measures DNA content per nucleus. One sample shows nuclei with duplicated DNA (sister chromatids present) but homologous chromosomes are paired and positioned as bivalents. Based on the information, which conclusion is most consistent with gamete formation at this stage?

A conservation biologist compares two closely related populations. In Population X, meiosis includes frequent crossing over; in Population Y, crossing over is rare, but chromosome segregation is normal. Both populations have similar mutation rates. Which statement best reflects the genetic variation introduced by meiosis that could affect adaptability over generations?