Final answer:
The correct answer is b. The correct term that describes the random orientation of homologous chromosome pairs during metaphase I is 'independent assortment', contributing to genetic variation in offspring by allowing for multiple combinations of maternal and paternal chromosomes in gametes.
Step-by-step explanation:
The term used to describe the way homologous pairs of chromosomes line up at random orientation during metaphase I is independent assortment. During the process of meiosis I, homologous chromosome pairs arrange themselves randomly along the metaphase plate. This randomness means that each gamete can contain any combination of the maternal and paternal chromosomes, which significantly contributes to genetic variation.
Independent assortment is a crucial component of sexual reproduction because it allows each resulting gamete to have a unique combination of alleles, contributing to the diversity in offspring. This concept aligns with Mendel's Law of Independent Assortment, which states that the alleles for separate traits are passed down independently of one another from parents to offspring. The orientation of the tetrads, or pairs of homologous chromosomes, is random for each of the 23 pairs during metaphase I, which is independent of the orientation of any other pair. This is distinguishable from crossing over, which happens during prophase I, where there is an exchange of genetic material between non-sister chromatids of homologous chromosomes.