Question

meiosis: stages of meiosis - meiosis i
name each phase of the first meiotic division and drag & drop the descriptions
centrosomes are at opposite poles and the spindle has formed. homologous chromosome pairs line up in the middle, oriented randomly.
the nuclear envelope breaks down and homologous chromosomes pair up, forming a tetrad. crossing over occurs.
the spindle fibers contract to pull chromosomes to opposite poles, separating the homologous pairs.
a nuclear envelope reforms at each pole and then cytokinesis divides the cell into two. each cell is haploid. the chromosomes will decondense.

Explanation:

Step1: Identify Prophase I

Match description: Nuclear envelope breaks, homologs pair, crossing over.
<Description match: The nuclear envelope breaks down and homologous chromosomes pair up, forming a tetrad. Crossing over occurs.>
Phase: Prophase I

Step2: Identify Metaphase I

Match description: Homologs line up at middle randomly.
<Description match: Centrosomes are at opposite poles and the spindle has formed. Homologous chromosome pairs line up in the middle, oriented randomly.>
Phase: Metaphase I

Step3: Identify Anaphase I

Match description: Spindle pulls homologs to poles.
<Description match: The spindle fibers contract to pull chromosomes to opposite poles, separating the homologous pairs.>
Phase: Anaphase I

Step4: Identify Telophase I & Cytokinesis

Match description: Nuclear envelope reforms, cell splits into haploids.
<Description match: A nuclear envelope reforms at each pole and then cytokinesis divides the cell into two. Each cell is haploid. The chromosomes will decondense.>
Phase: Telophase I & Cytokinesis

Answer:

1. (First phase, leftmost): Prophase I

• Corresponding description: The nuclear envelope breaks down and homologous chromosomes pair up, forming a tetrad. Crossing over occurs.

1. (Second phase): Metaphase I

• Corresponding description: Centrosomes are at opposite poles and the spindle has formed. Homologous chromosome pairs line up in the middle, oriented randomly.

1. (Third phase): Anaphase I

• Corresponding description: The spindle fibers contract to pull chromosomes to opposite poles, separating the homologous pairs.

1. (Fourth phase, rightmost): Telophase I & Cytokinesis

• Corresponding description: A nuclear envelope reforms at each pole and then cytokinesis divides the cell into two. Each cell is haploid. The chromosomes will decondense.