Bio B Trimester Final Review Notes

Organelles

  • Nucleus: Contains DNA; parts include nuclear membrane and nucleolus; found in Eukaryotic cells.
  • Nucleolus: Inside the nucleus, makes ribosomes.
  • Nuclear Envelope: Boundary of the nucleus.
  • Nuclear Pores: Tiny holes in the nuclear envelope.
  • Cell Membrane: Selectively permeable, regulates molecule movement.
  • Ribosome: Site for protein synthesis.
  • Mitochondria: Site of cellular respiration, converts chemical energy into ATP.
    • ATP stands for Adenosine Triphosphate.
    • Active transport needs ATP.
  • Chloroplast: Site of photosynthesis.

Cell Membrane

  • Main Function: Regulates flow of materials in and out of cell.
  • Main Parts: Phospholipids and proteins.
  • Selectively Permeable: Allows material movement through pores.
  • Phospholipid Parts: Phosphate group, glycerol, two fatty acids.

DNA Replication and Chromosomes

  • DNA Replication Purpose: Duplication of DNA.
  • Chromosomes: Made of tightly coiled DNA.
    • Not visible during interphase and cytokinesis.
    • Visible during prophase, metaphase, and anaphase.

Cell Cycle Stages:

  • Anaphase: Chromosome halves separate, moved by spindle fibers, no nucleus.
  • Metaphase: Chromosome pairs line up in the middle, no nucleus, spindle fibers present.
  • Interphase: Nucleus and nucleolus present, chromosomes loosely coiled.
  • Telophase: Two new nuclei form, cell begins to split, nuclear envelopes reappear.
  • Prophase: Nuclear envelope disappears, tightly coiled chromosomes.
  • Cytokinesis: Two new identical cells, cytoplasm splits.

DNA Structure

  • Outside: Sugar-phosphate backbone.
  • Rungs: Bases.
  • Intermolecular Force: Hydrogen bonds.
  • Base Pair Rules:
    • DNA: A--T, C--G
    • RNA: A--U, C--G

Macromolecules

  • DNA: Built by nucleotides.
  • Proteins: Built by amino acids.

DNA

  • Gene: Segment of DNA that determines a person's phenotype or traits.
  • DNA Replication: The process of duplicating DNA.

Reproduction

  • Types: Sexual and asexual.
  • Sexual reproduction leads to inheritance of diverse traits.
  • Meiosis: Comes before sexual reproduction, which produces sex cells or a zygote.
  • Gametes:
    • Male gamete: Sperm.
    • Female gamete: Egg.
  • Chromosome Number:
    • Human diploid cell: 46.
    • Human haploid cell: 23.
  • Sperm/egg cells are haploid.

Asexual (A), Sexual (S), or Both (B) Reproduction:

  • A: Produces identical offspring.
  • S: Creates non-identical offspring; produces diploid cell; uses gametes for fertilization; needs meiosis; produces a zygote; fertilization happens because of this reproduction.
  • B: Works through mitosis.
  • Sex cells are non-identical.

Miscellaneous

  • Chromosomes are tightly coiled pieces of DNA.

Embryology

  • Fertilization occurs after meiosis.
  • Cell: Basic unit of living things.
  • Tissue: Several cells form a tissue that has a specific function.
  • Organ: Two or more tissues form an organ.
  • System: Has defined shapes and functions within a body.

Transport

  • Active Transport: Moves molecules from low to high concentration (requires ATP).
  • Passive Transport: Moves molecules from high to low concentration.

Cell Size and Growth

  • Cells need to remain small in size to maintain homeostasis.
  • Diffusion rate changes with cell size; small cells diffuse molecules more efficiently.
  • Cells respond to growth as a stimulus; if cells get too large they might not maintain homeostasis.