Title: Question Set

Q: Explain the differences between mitosis and meiosis in terms of the genetic outcome and the types of cells they produce.
A: Mitosis and meiosis are both types of cell division but serve different purposes. Mitosis results in two daughter cells that are genetically identical to each other and to the parent cell. This equational division maintains the same number of chromosomes in each cell and is essential for growth, repair, and asexual reproduction in eukaryotes. On the other hand, meiosis consists of two divisions, resulting in four haploid daughter cells each with half the number of chromosomes of the original diploid parent cell. This reductional division is integral to sexual reproduction as it produces gametes (sperm and eggs) with a single set of chromosomes, which upon fusion during fertilization, restores the diploid state in the offspring.

Q: Describe the role of the spindle fibers during cell division and how they interact with chromosomes.
A: Spindle fibers are crucial components in cell division, formed by the spindle apparatus. Their primary role during mitosis and meiosis is to organize and separate chromosomes to ensure that each daughter cell receives the appropriate set of genetic material. During prometaphase, spindle fibers attach to the kinetochores on the centromeres of sister chromatids. These fibers then exert forces that align the chromosomes at the metaphase plate during metaphase. In anaphase, the spindle fibers shorten, pulling the sister chromatids apart to opposite poles of the cell, ensuring that each new nucleus receives one copy of each chromosome. This separation is critical for maintaining the integrity of the genetic information passed on to the daughter cells.

Q: Name the key checkpoints in the eukaryotic cell cycle and explain their significance.
A: The eukaryotic cell cycle features three main checkpoints: the G1/S checkpoint, the G2/M checkpoint, and the metaphase/anaphase checkpoint. The G1/S checkpoint, also known as the restriction checkpoint, ensures that the cell is ready for DNA replication, checking for DNA damage and sufficient cellular resources. If conditions are not met, the cell cannot proceed to the S phase. The G2/M checkpoint verifies that DNA replication has been completed correctly before the cell enters mitosis; this prevents the distribution of damaged or incomplete genetic material. The metaphase/anaphase checkpoint ensures that all chromosomes are properly attached to the spindle apparatus before allowing the cell to progress to anaphase, where the chromosomes are separated. These checkpoints are crucial for maintaining genomic stability and preventing the propagation of errors during cell division, reducing the risk of cancerous growth and other diseases associated with cell cycle dysregulation.