Question

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

a. chiasmata

b. recombination nodules

c. microtubules

d. kinetochores

Short answer

The correct answer is option a

Step-by-step solution

Step 1. Introduction

Metaphase is one of the stage in the cell cycle in which all genomic material condense into chromosomes.

Step 2. The explanation for the correct option

Option a is correct because during metaphase I homologous chromosomes are aligned at the metaphase plate and are held together at the chiasmata.

Step 3. The explanation for the incorrect options

Option b is incorrect because during metaphase I homologous chromosomes are attached to chiasmata.

Option c is incorrect because during metaphase I microtubules attach to the fused kinetochores of the system chromatids.

Option d is incorrect because during metaphase I homologous chromosomes are held together at the chiasmata instead of kinetochores.