Final answer:
Gametes with new combinations of alleles not found in the parents are called recombinant gametes, produced during meiosis by homologous recombination and crossing over. The correct option is b)recombinant
Step-by-step explanation:
Gametes that contain new combinations of alleles not present in the parents are called recombinant gametes. These gametes arise during the process of meiosis through homologous recombination, particularly during prophase I, where crossing over occurs between non-sister chromatids of homologous chromosomes.
This process produces gametes that have a different combination of alleles than that of the parent organisms, contributing to genetic diversity.
For example, consider a heterozygous individual (AaBb) that produces gametes. If the genes are linked, we would see primarily AB or ab gametes.
If genes are unlinked, due to independent assortment, all combinations such as AB, Ab, aB, and ab can be formed. However, through crossing over, new combinations such as Ab and aB arise, which are the nonparental (recombinant) types.
Studies by scientists like Morgan demonstrated that when these heterozygous individuals were crossed with homozygous recessive (aabb) organisms, the offspring included these recombinant types. The correct option is b)recombinant