03 – Mitosis and Meiosis

In this episode of the MCAT Prep Pod Biology Review, we dive deep into the mechanisms of cell division. We start by reviewing the difference between diploid and haploid cells, and the roles of somatic vs. germ cells. We then walk through the stages of the cell cycle, including interphase (G1, S, G2), the checkpoints that regulate progression (especially p53 and CDKs), and the process of cytokinesis.

We explore the full sequence of mitosis – prophase, metaphase, anaphase, and telophase (PMAT). and explain how one diploid parent cell produces two genetically identical diploid daughter cells for growth and tissue repair.

Next, we break down meiosis, the specialized process that occurs in germline cells to produce gametes. We go over how meiosis I separates homologous chromosomes and generates genetic diversity through crossing over (recombination) and independent assortment, while meiosis II separates sister chromatids, ultimately producing four genetically distinct haploid cells.

We highlight key differences between mitosis and meiosis, introduce useful mnemonics (like PMAT = Pass Me A Taco), and explain how errors in chromosome separation (such as nondisjunction) can lead to aneuploidy and disorders like Down syndrome (Trisomy 21).

Topics covered include:

• The cell cycle: G1, S, G2, M phase, and checkpoints

• Role of tumor suppressor genes (e.g., TP53), cyclins, and CDKs

• The steps and significance of mitosis and cytokinesis

• The stages of meiosis I and II, including synapsis and tetrad formation

• Genetic variation: crossing over, independent assortment, and random fertilization

• Key differences between mitosis and meiosis

• MCAT-relevant disorders: nondisjunction and aneuploidy

This episode is packed with core cell biology that frequently appears on the MCAT. It’s also supported by downloadable notes, diagrams, and flashcards to help reinforce what you’ve learned.