Cell Structure and Function

What is the main event of diplotene stage in prophase I?

• DNA replication occurs
• Homologous chromosomes begin to repel each other but remain attached at chiasmata
• Crossing-over begins
• Spindle fibers form

What is a bivalent in meiosis also known as?

• Diploid
• Tetravalent
• Tetrad
• Both Tetravalent and Tetrad

What happens during the pachytene stage of prophase I in meiosis?

• Homologous chromosomes begin to pair
• Crossing-over occurs between non-sister chromatids at the end of pachytene
• Nuclear membrane reforms
• Sister chromatids separate

Why is Prophase I of Meiosis I considered longer than the prophase of mitosis?

• Because DNA replication occurs here
• Because it has fewer sub-stages
• Because cytokinesis happens simultaneously
• Because it involves complex processes like synapsis and crossing over

Which of the following is a key feature of chromosomes during the Leptotene stage?

• Chromosomes are fully separated
• Chromosomes appear as long, thin threads with chromomeres
• Homologous chromosomes are paired
• Crossing over occurs