At metaphase I, homologous chromosomes are connected only at what structures?

chiasmata

recombination nodules

microtubules

kinetochores

The correct answer is option - chiasmata.

Explanation:

Chiasma is a singular form of chiasmata. chaisma is the site where two chromatids belonging to homologous chromosomes. It is the site where the genetic exchange takes place and crossing over occurs between the strands.

This structure form or occur at metaphase I of the cell cycle. In this stage, the chromosomes align on the metaphase plate.

Thus, the correct answer is option - chiasmata.