Which process occurs in fungi and has the opposite effect on a cell's chromosome number than does meiosis I?

karyogamy
mitosis
plasmogamy
crossing-over
binary fission

I know that it is not mitosis. And I don't think that it is crossing-over. I was thinking that it was karyogamy. What do you think??

THANK YOU!

It is karyogamy.

You are correct in eliminating mitosis and crossing-over as the options. Karyogamy is indeed the process that occurs in fungi and has the opposite effect on a cell's chromosome number compared to meiosis I. During karyogamy, two haploid nuclei fuse to form a diploid nucleus, resulting in an increase in chromosome number. Therefore, karyogamy is the process you are looking for.

Based on the information you provided, the process that occurs in fungi and has the opposite effect on a cell's chromosome number than does meiosis I is karyogamy.

Karyogamy is the fusion of two haploid nuclei, resulting in the formation of a diploid nucleus. In contrast, meiosis I is a process in which a diploid cell divides into two haploid cells, reducing the chromosome number by half.

To determine the correct answer, you can eliminate options that are not the opposite of meiosis I or do not involve the fusion of nuclei.

You correctly ruled out mitosis because it also involves the production of cells with the same chromosome number (rather than the opposite effect). Crossing-over is a specific event that occurs during meiosis where genetic information is exchanged between homologous chromosomes, and it does not involve the fusion of nuclei. Binary fission is a form of cell division that occurs in prokaryotes but not in fungi.

Therefore, karyogamy is the most likely correct answer based on the information you provided.