Meiosis

Question 1

What occurs in early prophase I?

Answer 1

• nuclear envelope begins to break down, chromosomes condense, spindle apparatus begins to form
• synapses form

Question 2

What occurs in late prophase I?

Answer 2

• nuclear envelope breaks down
• the two homologs in each bivalent attach to microtubules coming from opposing poles of the spindle apparatus
• homologs separate at many points, stay together at chiasmata
• crossing over

Question 3

What occurs in metaphase I?

Answer 3

• kinetocore microtubules move the pairs of bivalents to the metaphase plate
• the bivalent straddles the metaphase plate with unique orientation

Question 4

What occurs in anaphase I?

Answer 4

• sister chromatids remain together and each homolog pair is attached to a different spindle pore
• they separate and move to opposite poles of the spindle apparatus

Question 5

What occurs in prophase II?

Answer 5

• spindle apparatus reforms

Question 6

What occurs in metaphase II?

Answer 6

• chromosomes line up at the middle of the spindle apparatus

Question 7

What occurs in anaphase II?

Answer 7

• sister chromatids separate, begin moving to opposite poles of the spindle apparatus

Question 8

What occurs in telophase II?

Answer 8

• daughter chromosomes finish moving to opposite poles

- spindle apparatus disassembles

Question 9

What occurs in telophase I?

Answer 9

• homologs finish moving to opposite sides of the spindle

Question 10

What is the end result in meiosis I?

Answer 10

• reduction division that separates homologous chromosomes
• results in 2 daughter cells that have only one chromosome of each homologous pair
• sister chromatids remain attached
• random assortment of maternal and paternal chromosomes

Question 11

What is the end result in meiosis II?

Answer 11

• separates sister chromatids of the previously replicated chromosome, no replication takes place
• produces 4 haploid daughter cells with unreplicated chromosomes