Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Which of the following events occurs during meiosis I, but not during mitosis?
A
Homologous chromosomes pair and undergo crossing over
B
Chromosomes align individually at the metaphase plate
C
The nuclear envelope breaks down
D
Sister chromatids are separated into different cells
Verified step by step guidance
1
Understand the key difference between meiosis and mitosis: Meiosis involves two rounds of division (meiosis I and meiosis II) and results in four haploid cells, while mitosis involves one round of division and results in two diploid cells.
Focus on meiosis I, which is unique because homologous chromosomes pair up and exchange genetic material through crossing over. This does not occur in mitosis.
Recall that during metaphase I of meiosis, homologous chromosomes align as pairs at the metaphase plate, whereas in mitosis, individual chromosomes align at the metaphase plate.
Recognize that the nuclear envelope breaks down in both meiosis and mitosis, so this event is not unique to meiosis I.
Understand that sister chromatids are separated during mitosis and meiosis II, but in meiosis I, homologous chromosomes are separated into different cells, making crossing over and homologous pairing unique to meiosis I.