BIO MAIN IDEAS

📘 Module 9: Cellular Reproduction

  1. Surface Area to Volume Ratio

    • A smaller ratio signals the cell to divide to maintain efficiency in transporting materials.

  2. Advantages of Small Cell Size

    • Increases efficiency of nutrient/waste exchange and communication.

  3. DNA Organization

    • DNA is structured into chromatin, then chromosomes, with genes located on chromosomes.

  4. Cell Cycle Phases and Events

    • Includes interphase (G1, S, G2), mitosis (PMAT), and cytokinesis.

  5. Cell Cycle Regulation

    • Controlled by checkpoints and regulatory proteins to ensure proper division.

  6. Mitosis and Its Events

    • Mitosis divides the nucleus: prophase, metaphase, anaphase, telophase.

  7. Apoptosis

    • Programmed cell death, removes damaged or unneeded cells.

  8. Meiosis and Its Events

    • Two rounds of division produce four genetically unique haploid gametes.

  9. Examples of DNA Nondisjunction

    • Trisomy 21 (Down Syndrome), Turner Syndrome, and Klinefelter Syndrome.

  10. Cellular Differentiation

  • Process by which unspecialized cells become specialized in structure and function.

  1. Embryonic vs. Adult Stem Cells

  • Embryonic can become any cell type; adult stem cells have limited potential.

🧬 Module 10: Genetics & Patterns of Inheritance

  1. Mendel’s Conclusions

    • Traits are inherited as discrete units (genes); one allele from each parent.

  2. Law of Segregation & Law of Independent Assortment

    • Alleles separate during gamete formation; genes separate independently.

  3. Monohybrid and Dihybrid Crosses

    • Predict offspring genotypes and phenotypes using Punnett squares.

  4. Role of Crossing Over and Independent Assortment

    • Increases genetic variation during meiosis.

  5. Selective Breeding: Pros and Cons

    • Produces desired traits but may reduce genetic diversity and increase disease risk.

  6. Test Crosses

    • Used to determine the unknown genotype of an individual showing a dominant trait.

  7. Pedigrees

    • Diagrams that track the inheritance of traits in families.

  8. Complex Patterns of Inheritance

    • Includes incomplete dominance, codominance, epistasis, sex-linked, polygenic traits, and dosage compensation.

🧪 Module 11: Molecular Genetics

  1. DNA Structure and Orientation

    • Double helix with anti-parallel strands and complementary base pairing (A-T, G-C).

  2. Experiments Leading to Discovery of DNA Function

    • Griffith, Avery, Hershey-Chase demonstrated DNA is the molecule of heredity.

  3. DNA Replication

    • Semi-conservative process involving unwinding, base pairing, and joining new strands.

  4. Transcription

    • DNA is transcribed into mRNA in the nucleus.

  5. mRNA Processing

    • Includes capping, poly-A tail addition, and splicing out introns.

  6. mRNA, rRNA, and tRNA Comparison

    • mRNA carries code, rRNA forms ribosomes, tRNA brings amino acids.

  7. Translation

    • mRNA is translated into a protein at the ribosome using codons and anticodons.

  8. Reading the Genetic Code

    • Codons are 3-letter RNA sequences that specify amino acids.

  9. Mutations and Their Timing

    • Can occur during DNA replication or meiosis; may affect protein function.

  10. Examples of Mutations

  • Sickle cell anemia, cystic fibrosis, color blindness.

  1. Gene Regulation Example

  • The lac operon in bacteria controls the expression of genes in response to lactose presence.