Question

A dikaryotic cell has
A. Two haploid nuclei
B. Diploid zygotes
C. Two similar nuclei
D. Two dissimilar haploid nuclei

Answer 1

Hint: Dikaryotic cells are commonly formed during the sexual reproduction in fungi. They are also known as heterokaryons. The two genetic materials fuse together and form the zygospore.

Complete answer:
The term dikaryon is generally meant by the fusion of the two genetically dissimilar nuclei of two cells that belong to two different strains. The dikaryon is a nuclear feature which is a very unique feature of kingdom fungi. The green alga Derbesia has been long regarded as an exception until the heterokaryotic hypothesis was challenged by further studies. Compatible cell-types can fuse cytoplasms known as plasmogamy. When this occurs, the two nuclei of two cells pair off and cohabit without fusing known as karyogamy. This can be maintained for all the cells of the hyphae by synchronously dividing so that pairs are passed to newer cells. In the Ascomycota, this type of attribute is most commonly found in the ascogenous hyphae and ascocarp while the bulk of the mycelium remains monokaryotic. In the Basidiomycota, this is generally regarded as the dominant phase, with most Basidiomycota monokaryons weakly growing and though short-lived.
So, the correct option is option D-Two dissimilar haploid nuclei

Note: The name dikaryon comes from the Greek word which means "two" and karyon which means "nut", referring to the cell nucleus. The formation of a dikaryon is a plesiomorphic character for the subkingdom Dikarya, which contains the Basidiomycota and the Ascomycota. However, some fungi in each of these phyla have evolved other methods for maintaining the dikaryons, and therefore neither croziers nor clamp connections are ubiquitous in either phylum.