Question

meiosis occurs in a series of different phases and creates genetically unique reproductive cells. which process helps make meiotic cells genetically different and occurs during prophase i, but not during prophase ii?
fertilization
independent assortment
crossing over
chromosome replication

Explanation:

• Fertilization: It is the union of gametes (sperm and egg) and occurs after meiosis, not during prophase I or II of meiosis.
• Independent assortment: This occurs during metaphase I (not specifically during prophase I) and is about the random alignment of homologous chromosome pairs at the metaphase plate.
• Crossing over: During prophase I of meiosis, homologous chromosomes pair up (synapsis) and exchange genetic material (crossing - over). This does not occur in prophase II as there are no homologous pairs to pair up (the cell is haploid at prophase II).
• Chromosome replication: Occurs before meiosis (in the S - phase of interphase), not during prophase I or II.

Answer:

crossing over