ap bio final rev

Biochemical Reactions

  • Dehydration Synthesis
      - The process involves removing water molecules to build covalent bonds, resulting in larger molecules (e.g., monomers to polymers). It is anabolic in nature.

  • Hydrolysis
      - This process involves adding water to break covalent bonds, leading to the breakdown of larger molecules into smaller units (e.g., polymers to monomers). It is catabolic in nature.

Gene Expression Regulation

  • Gene expression is indicated by the production of proteins; if a protein is produced, the corresponding gene is expressed.

  • If a protein is not produced, the gene is blocked or not expressed.

  • Important to carefully analyze details regarding gene expression in questions.

Genetics and Punnett Squares

  • Understanding genotypic probability is crucial.

  • Example problem involved a heterozygous mother (Aa) and a homozygous dominant father (AA):
      - Calculating the genotype probability for offspring using Punnett squares.
        - Conduct separate Punnett squares for each trait if there are multiple traits (e.g., traits A, B, C).
        - Multiply the probabilities from each square for overall genotype probability.

Prokaryotes vs. Eukaryotes

  • Common Features:
      - All living cells have:
        - Ribosomes
        - Phospholipid bilayer (cell membrane)
        - Cytoplasm
        - DNA (or genetic material)

  • Differences:
      - Prokaryotic DNA is circular with no telomeres.
      - Eukaryotic DNA is linear with telomeres.
      - Prokaryotes do not have nucleus or histones.
      - Prokaryotic transcription and translation can occur simultaneously due to the lack of introns and nuclear membrane.

Mitosis and Meiosis

  • Mitosis Promoting Factor (MPF):
      - Composed of cyclin-dependent kinase (CDK) and cyclic substances.
      - CDK is an enzyme that is not consumed and remains available throughout the cell cycle.
      - Cyclin concentrations vary, peaking during specific cell cycle phases.
      - MPF regulates entry into mitosis, while the degradation of cyclin leads to exit from mitosis.

DNA Replication

  • Leading Strand:
      - Synthesized continuously as helicase opens up the DNA strands.
      - DNA polymerase adds nucleotides in the 5’-3’ direction continuously.

  • Lagging Strand:
      - Synthesized discontinuously in fragments (Okazaki fragments) due to the opposite orientation of helicase.
      - Requires ligase to connect fragments.

Evolutionary Biology

  • Key Terms:
      - Homologous structures: Similar due to common ancestry, diverging in function (e.g., forelimbs of mammals).
      - Analogous structures: Different structures that have evolved similarities due to similar environmental pressures, not common ancestry (e.g., wings of bats and insects).

  • Darwinian Evolution:
      - Variation is essential, stemming from sexual reproduction in eukaryotes and mutations in prokaryotes.
      - Environmental changes lead to differential survival and reproduction of individuals based on favorable traits.

Endosymbiotic Theory

  • Proposes that mitochondria and chloroplasts are derived from prokaryotic cells that were engulfed by ancestral eukaryotic cells.

  • Both chloroplasts and mitochondria possess their own DNA and replicate via binary fission, similar to bacterial division.

Hardy-Weinberg Principle

  • Conditions for a non-evolving population:
      - No mutation
      - Random mating
      - No natural selection
      - Large population size
      - No gene flow (no migration of alleles).

Genetic Techniques

  • PCR (Polymerase Chain Reaction):
      - Used to amplify specific DNA segments for study.

  • Gel Electrophoresis:
      - Technique for separating DNA fragments by size. Bands on a gel indicate genetic relationships; similar bands suggest relatedness.

  • Restriction Enzymes:
      - Enzymes that cut DNA at specific sequences used in genetic engineering and cloning.

Osmosis and Solute Movement

  • Water moves through osmosis (from hypo- to hypertonic environments) while solute movement occurs from high to low concentration.

  • Changes in mass or volume are indicators of water movement in cells. Assess changes to deduce unknown concentrations in solutions.

Signal Transduction Pathways

  • Understanding diagrams and questions regarding cell signaling; read provided diagrams to answer questions based on visual information.

Gene Linkage

  • When traits are linked on the same chromosome, they do not assort independently during gamete formation.

  • Recombinants can indicate genes that assort independently, while linked genes show fewer recombinants.

Summary

  • Expect both MCQ and FRQ assessments on relevant topics. Pay attention to preparation strategies including revision of practice problems, understanding the significance of central concepts, and refining analytical skills for graph interpretation and experimental situations.