Y

Bio Notes (Flashcards)

🧬 Chapter 10 & 14: Genetics & Human Impact

🔹 Meiosis

  • Steps of Meiosis I & II:

    • Meiosis I: Homologous chromosomes separate

      • Prophase I, Metaphase I, Anaphase I, Telophase I

    • Meiosis II: Sister chromatids separate (like mitosis)

  • Result: 4 haploid gametes (sex cells)

🔹 Key Terms

  • Heredity: Passing traits from parents to offspring

  • Genotype: Genetic makeup (e.g., Aa)

  • Phenotype: Physical traits (e.g., blue eyes)

  • Homozygous: Same alleles (AA or aa)

  • Heterozygous: Different alleles (Aa)

  • Dominant: Trait that shows if at least one allele is present

  • Recessive: Trait only shown if both alleles are recessive

  • F1 Plants: First filial generation from parental cross

  • Hybrids: Offspring of two different traits or species

  • Gamete: Sex cell (sperm or egg)

  • Nondisjunction: Chromosomes don't separate properly

  • Plasmid: Circular DNA in bacteria

  • Genes: DNA segments that code for traits

🔹 Punnett Squares

  • Monohybrid: One trait (Aa × Aa)

  • Dihybrid: Two traits (AaBb × AaBb)

  • Sex-linked: Traits on X chromosome (e.g., color blindness)

  • Incomplete dominance: Blended traits (red + white = pink)

  • Codominance: Both alleles show (e.g., AB blood type)

🔹 Other Key Concepts

  • Blood Typing:

    • Universal donor: O-

    • Universal recipient: AB+

  • Sex Chromosomes:

    • Male: XY

    • Female: XX

  • Independent Assortment: Genes sort independently in gametes

  • Probability: Chance of trait showing (used with Punnett squares)

🔹 Genetic Disorders

  • Cystic Fibrosis: Thick mucus buildup

  • Sickle-cell Anemia: Misshaped red blood cells

  • Huntington’s Disease: Brain disorder, dominant trait

  • Down Syndrome: Extra chromosome 21

🔹 Karyotype & Pedigree

  • Karyotype: Picture of chromosomes

  • Pedigree: Family trait chart

🧬 Chapter 11-12: DNA & Protein Synthesis

🔹 DNA vs. RNA

  • DNA: Double helix, bases A-T, C-G

  • RNA: Single strand, bases A-U, C-G

🔹 Nucleotide Components

  • Sugar (deoxyribose or ribose), phosphate, nitrogen base

🔹 Scientists

  • Watson, Crick, Wilkins, Franklin: Discovered DNA structure

  • Nobel Prize: Watson, Crick, Wilkins (Franklin died before being recognized)

🔹 Key Processes

  • DNA Replication: Makes identical DNA copies

  • Transcription: DNA → mRNA (in nucleus)

  • Translation: mRNA → Protein (at ribosome)

  • Use a codon chart to find amino acids from mRNA codons

🔹 Mutations

  • Point mutation: One base is changed

  • HOX Genes: Control body plan during development

🧪 Ch. 14/15: Genetic Engineering

🔹 Biotech Tools

  • Selective Breeding: Humans breed for traits

  • Mutations: Used to introduce variation

  • Cloning: Copy of an organism

  • Transformation: Putting foreign DNA into cells

  • Recombinant DNA: DNA from multiple sources combined

  • GMO / Transgenic Organisms: Organisms with foreign DNA

🌍 Ch. 6, 8, 13: Evolution

🔹 Evidence for Evolution

  • Fossils: Show changes over time

  • Comparative Anatomy: Similar bone structures (homologous)

  • Embryology: Similar embryos = common ancestry

  • Selective Breeding: Human-controlled evolution

  • Direct Observation: Bacteria resistance

  • Law of Superposition: Oldest fossils are deeper in layers

  • Homologous = same structure, different function

  • Analogous = same function, different structure

  • Vestigial = useless traits (e.g., human tailbone)

🔹 Evolution Theories

  • Darwin: Natural selection, survival of the fittest

  • Lamarck: Acquired traits (not accepted today)

  • Hutton & Lyell: Earth is old and changes slowly

  • Darwin’s Voyage: Galapagos finches adapted to islands

🔹 Adaptations

  • Structural: Physical features (e.g., thick fur)

  • Behavioral: Actions (e.g., migration)

  • Physiological: Internal processes (e.g., poison production)

🔹 Speciation & Isolation

  • Species: Can breed and produce fertile offspring

  • Reproductive Isolation: Can't breed

  • Types:

    • Geographic: Physical barrier

    • Temporal: Different mating times

    • Ecological: Live in different environments

  • Genetic Drift: Random gene changes

  • Adaptive Radiation: One species → many

  • Convergent Evolution: Unrelated look alike

  • Divergent Evolution: Related become different

  • Gradualism: Slow changes

  • Punctuated Equilibrium: Quick bursts of change