Question

which activities occur during prophase ii? check all that apply. ☐ dna condenses to form chromosomes. ☐ each chromosome pairs up with its mate. ☐ spindle fibers form. ☐ chromosomes move to the opposite end of the cell. ☐ the nuclear envelope disappears.

Explanation:

To determine the activities in prophase II of meiosis:

• DNA condenses to form chromosomes: In prophase II, chromatin (DNA - protein complex) condenses into visible chromosomes. This is a key event as the cell prepares for division.
• Spindle fibers form: The spindle apparatus starts to assemble during prophase II. Spindle fibers are essential for moving chromosomes during cell division.
• The nuclear envelope disappears: The breakdown of the nuclear envelope occurs in prophase II, allowing the spindle fibers to interact with the chromosomes.

Now, let's analyze the incorrect options:

• Each chromosome pairs up with its mate: Homologous chromosome pairing (synapsis) occurs in prophase I, not prophase II.
• Chromosomes move to the opposite end of the cell: Chromosome movement to opposite poles happens during anaphase, not prophase.

Answer:

• $\boldsymbol{\square}$ DNA condenses to form chromosomes. (checked)
• $\boldsymbol{\square}$ Each chromosome pairs up with its mate. (not checked)
• $\boldsymbol{\square}$ Spindle fibers form. (checked)
• $\boldsymbol{\square}$ Chromosomes move to the opposite end of the cell. (not checked)
• $\boldsymbol{\square}$ The nuclear envelope disappears. (checked)

So the correct checked options are: DNA condenses to form chromosomes, Spindle fibers form, The nuclear envelope disappears.