AP BIOLOGY

Detailed explanation-1: -During metaphase I, the tetrads move to the metaphase plate with kinetochores facing opposite poles. The homologous pairs orient themselves randomly at the equator. This event is the second mechanism that introduces variation into the gametes or spores.

Detailed explanation-2: -Metaphase I: The tetrads line up along the metaphase plate. Microtubules originating from the centrosomes at the 2 opposite poles of the cell attach to the kinetochores of each chromosome. Anaphase I: Homologous chromosomes are separated by the microtubules to opposite poles of the cell.

Detailed explanation-3: -In a real cell, chromosomes would not be visible during interphase of the cell cycle. During prophase I and metaphase I of meiosis, a chromosome consists of a tetrad (4 chromatids or 4 DNA molecules) and is reduced to two chromatids (2 DNA molecules) by the time metaphase II occurs.

Detailed explanation-4: -Metaphase I follows prophase I and precedes anaphase I.In meiosis I, the lining-up stage of metaphase I is relatively rapid. Tetrads or bivalents (a pair of chromosomes with four chromatids (2 originals, 2 copies) are pulled into line at what is known as the metaphase (or equatorial) plate.

Detailed explanation-5: -Metaphase I: Instead of all chromosomes pairing up along the midline of the cell as in mitosis, homologous chromosome pairs line up next to each other. This is called synapsis. Homologous chromosomes contain the matching alleles donated from mother and father.