Final answer:
In this figure, label A points to the sister chromatids that hold the bivalent together, while label B shows the crossover that results from a crossing over. During meiosis, homologous chromosomes come together to form a synapse and exchange genetic material through crossover.
Step-by-step explanation:
In this figure, label A points to the sister chromatids, which hold the bivalent together, while label B shows the crossover, which is the connection that results from a crossing over.
During meiosis, homologous chromosomes come together to form a synapse, where they are bound tightly together by a protein lattice called a synaptonemal complex. The sister chromatids, which are identical copies of each chromosome, are produced by DNA replication.
During crossover, or recombination, two homologous chromosomes align and exchange segments of genetic material, resulting in recombinant and non-recombinant chromosomes.