Week 3

Chapter 3: Molecular Biology and Genetics

DNA Replication & Cell Cycle:
- Describe the processes of DNA replication and the overall cell cycle.
Mitosis vs. Meiosis:
- Highlight the key differences between mitosis and meiosis.
Protein Synthesis:
- Explain the steps of protein synthesis including transcription and translation.
Mendelian Inheritance:
- Use Mendelian principles to predict genotypes and phenotypes.
Genetic Inheritance Patterns:
- Explain complexities in genetic inheritance and polygenic traits.
Genetic Testing Ethics:
- Discuss challenges and bioethical issues related to genetic testing.

Hayley Mann's journey began in 2003 with the Human Genome Project.
Genetics intersects with biological anthropology to study human variation through molecules (cells, proteins, etc.).
Improved scientific methods have enhanced our understanding of ancient biomolecules and how they relate to human evolution.

Four Basic Types:
- Proteins: Essential for cellular tasks; composed of amino acids.
- Lipids: Forms cell membranes (phospholipid bilayer); includes fats and hormones.
- Carbohydrates: Provide energy (glucose).
- Nucleic Acids: Store genetic information (DNA/RNA).

Prokaryotes: Simple, single-cell organisms without membrane-bound organelles (e.g., bacteria).
Eukaryotes: More complex, can be single or multi-celled; contain membrane-bound organelles.
- Differences: Eukaryotic cells have a nucleus and specialized organelles, while prokaryotes do not.

Nucleus: Contains DNA, the genetic blueprint.
Mitochondria: Energy production (ATP); possess their own DNA.
Endoplasmic Reticulum (ER): Rough (with ribosomes) synthesizes proteins; smooth (without ribosomes) synthesizes lipids.
Golgi Apparatus: Modifies and packages proteins.
Ribosomes: Sites of protein synthesis.
Lysosomes: Contains enzymes for digestion within the cell.

Genetics studies heritable traits, with variations becoming evident across generations.
Molecular Geneticists: Examine mechanisms that create variation, such as mutations and cell division.
Ancient DNA (aDNA): Helps explore historical genomic data.

Semi-conservative method: Each daughter DNA strand has one original and one new strand.
Stages of Replication:
1. Initiation: DNA unwinds at the replication fork.
2. Elongation: New nucleotides are added by DNA polymerase.
3. Termination: Replication completes, resulting in two identical DNA molecules.

Mitosis: Divides somatic cells into two identical diploid cells for growth and repair.
Meiosis: Produces haploid gametes (sperm and egg), increasing genetic diversity through recombination.

Mendel's Contributions:
- Dominant and recessive traits; established laws of inheritance (Segregation and Independent Assortment).
Key Terms:
- Genotype: Composition of alleles (e.g., BB, Bb).
- Phenotype: Observable traits derived from genotype (e.g., purple flowers).
- Punnett Square: Tool for predicting genetic outcomes.

Polygenic Traits: Influenced by multiple genes (e.g., height).
Pleiotropy: A single gene affects multiple traits (e.g., Marfan syndrome).
Epigenetics: Environmental factors regulate gene expression without altering DNA sequences.

Advancements: Newborn screenings, awareness of diseases through genetic testing.
Clinical Testing: Involves medical guidance; includes carrier screening and IVF applications.
Direct-to-Consumer (DTC) Testing: Allows individuals to access their genetic data without medical intermediaries but raises ethical concerns regarding interpretation and understanding of results.

Understanding genetics at various levels (organismal, cellular, molecular) is essential.
Genetic theory continues to evolve with an emphasis on both simple Mendelian traits and complex polygenic inheritance.