Jun 21, 2025
Cell division is the process by which cells reproduce and multiply, playing a crucial role in growth, development, repair, and reproduction in living organisms. There are two main types of cell division: mitosis and meiosis.
Q1: What are the main phases of the cell cycle?
A: The main phases are interphase (G1, S, G2) and the M phase (mitosis or meiosis). Interphase is when the cell grows and replicates its DNA, while the M phase is when the cell divides.
Q2: What is mitosis?
A: Mitosis is a type of cell division that produces two genetically identical daughter cells from a single parent cell. It is important for growth, tissue repair, and maintenance in multicellular organisms.
Q3: What are the stages of mitosis?
A: The stages of mitosis are prophase (chromosomes condense and spindle forms), metaphase (chromosomes align at the cell’s equator), anaphase (sister chromatids separate), telophase (nuclear membranes reform), followed by cytokinesis (division of the cytoplasm).
Q4: What is meiosis?
A: Meiosis is a type of cell division that occurs in reproductive cells, resulting in four genetically different daughter cells, each with half the chromosome number of the parent cell. It consists of two divisions: meiosis I and meiosis II.
Q5: Why is meiosis important?
A: Meiosis is important because it introduces genetic variation through recombination and independent assortment, and it reduces the chromosome number by half, which is essential for sexual reproduction.
Q6: What is the difference between mitosis and meiosis?
A: Mitosis produces two genetically identical cells with the same chromosome number as the parent, while meiosis produces four genetically different cells with half the chromosome number.
Q7: What happens during the S phase of interphase?
A: During the S phase, DNA replication occurs, resulting in the duplication of chromosomes in preparation for cell division.
Q8: What is cytokinesis?
A: Cytokinesis is the process that follows mitosis or meiosis, where the cytoplasm divides, resulting in two separate daughter cells.
Q9: What is the significance of mitosis?
A: Mitosis is significant for the growth of organisms, repair and replacement of damaged tissues, and maintenance of genetic stability by producing identical cells.
Q10: What is the significance of meiosis?
A: Meiosis is significant because it ensures genetic diversity in offspring and maintains the chromosome number across generations by producing gametes with half the original chromosome number.
Q11: What are the key differences between meiosis I and meiosis II?
A: Meiosis I is the reductional division where homologous chromosomes separate, reducing the chromosome number by half. Meiosis II is similar to mitosis, where sister chromatids separate, resulting in four haploid cells.
Q12: How does genetic variation arise during meiosis?
A: Genetic variation arises through crossing over (exchange of genetic material between homologous chromosomes during prophase I) and independent assortment (random distribution of chromosomes to daughter cells).
Q13: What roles do G1 and G2 phases play in the cell cycle?
A: G1 is the phase of cell growth and preparation for DNA replication, while G2 is the phase where the cell prepares for mitosis by synthesizing proteins and organelles needed for cell division.
Q14: What is the importance of the cell cycle checkpoints?
A: Cell cycle checkpoints ensure that each phase is completed accurately before the next phase begins, preventing errors in cell division and maintaining genetic stability.
Q15: What is the outcome if cell division is not properly regulated?
A: Improper regulation of cell division can lead to uncontrolled cell growth, resulting in tumors or cancer, or can cause cell death or genetic disorders due to errors in chromosome number or structure.