QCM : Cell Division Mastery — 10 questions

Explication

The correct sequence of mitosis stages is prophase, metaphase, anaphase, and telophase, as described in the content. This sequence reflects the orderly progression of nuclear division, starting with chromosome condensation and nuclear membrane breakdown, alignment at the metaphase plate, separation of sister chromatids, and finally nuclear reformation.

Explication

Walther Flemming is credited with early studies of cell division, including the description of cytokinesis in both plant and animal cells, making him the correct attribution for the differences in cytokinesis processes.

Explication

During metaphase in mitosis, individual chromosomes line up at the metaphase plate, ensuring each sister chromatid is attached to spindle fibers from opposite poles. In contrast, during metaphase I of meiosis, homologous chromosomes (forming tetrads) align in two parallel lines at the metaphase plate, reflecting the pairing of homologs. This difference in alignment pattern is a key distinguishing feature between the two processes.

Explication

A model simulation of meiosis involves using physical or visual models, such as beads and magnets, to demonstrate the pairing, crossing-over, and separation of chromosomes during meiosis, making the process easier to understand.

Explication

Chromosomes stain as colored bodies, which makes them visible under the microscope during slide examination, allowing identification of different stages of mitosis or meiosis.

Explication

Interphase activities occur before mitosis begins, during the G1, S, and G2 phases, where the cell prepares for division by growing, replicating DNA, and synthesizing necessary proteins. It is the preparatory phase that sets the stage for mitosis or meiosis, making 'Before mitosis begins' the correct answer.

Explication

Mitosis is the process of nuclear division that results in two genetically identical nuclei, which is essential for growth and tissue repair in multicellular organisms.

Explication

Crossing-over exchanges genetic material between non-sister chromatids, which increases genetic variation in gametes, a key effect that promotes diversity in offspring.

Explication

The correct application of haploid cells in sexual reproduction is that they fuse during fertilization to form a diploid zygote, restoring the full chromosome number. The other options are incorrect because haploid cells are produced by meiosis, not mitosis; they do not undergo mitosis to produce gametes; and they contain only one set of chromosomes, not two.

Explication

The main role of meiosis stages is to produce haploid gametes that contain half the chromosome number of the original cell, with genetic variation introduced through crossing-over and independent assortment, which is essential for sexual reproduction.