Scelta multipla
During which phase of meiosis I do homologous pairs of chromosomes separate?
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12. Meiosis
Meiosis I
Scelta multipla
In meiosis, homologous chromosomes of a tetrad cross over and form chiasmata.
A
sister chromatids; a dyad; centromeres
B
non-homologous chromosomes; a tetrad; kinetochores
C
homologous chromosomes; a dyad; spindle fibers
D
homologous chromosomes; a tetrad; chiasmata
Guida verificata passo dopo passo1
Understand the context of meiosis: Meiosis is a type of cell division that reduces the chromosome number by half, producing four haploid cells. It involves two stages: Meiosis I and Meiosis II. The crossing over of homologous chromosomes occurs during Prophase I of Meiosis I.
Define the key terms: Homologous chromosomes are pairs of chromosomes (one from each parent) that have the same genes at the same loci but may have different alleles. A tetrad is a group of four chromatids formed by the pairing of two homologous chromosomes during Prophase I. Chiasmata are the points where crossing over occurs between homologous chromosomes.
Analyze the process of crossing over: During Prophase I, homologous chromosomes pair up to form a tetrad. At this stage, segments of chromatids may exchange genetic material at points called chiasmata. This process increases genetic diversity in the resulting gametes.
Eliminate incorrect options: Sister chromatids are identical copies of a single chromosome and do not form chiasmata. Non-homologous chromosomes do not pair up to form tetrads. Dyads and spindle fibers are involved in later stages of meiosis but are not directly related to the formation of chiasmata.
Conclude with the correct answer: The correct answer is 'homologous chromosomes; a tetrad; chiasmata,' as these terms accurately describe the structures and processes involved in crossing over during meiosis.
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