IB Biology

• what is diffusion?

  the move of cells moving from high to low concentration
• What is Osmosis?

  the passing of water- diffusion of water or solvents through a membrane that blocks solutes
• How does water move?

  water moves from hypertonic to areas
• Hypertonic

  areas with higher solute concentration
• hypotonic?

  areas with lower solute concentration
• Active transport movement?

  moves from low to high concentration
• what is the basic unit of life?

  the cell
• what is the two main types of cells?

  prokaryotes and eukaryotes cells
• which types of cells lacksa true nucleaus

  prokaryotic cells
• which type of cell contains membrane-bound organelles


  eukaryotic cells
• name one principle of cell theory

  all living organisms are made of one or more cells
• how do you calculate magnification in microscopy?


  magnification= size of image/actual size of object
• what is the ultrastructure of a cell?


  The detailed structure of a cell is visible only with an electron microscope, including organelles.
• what is the function of the nucleus

  it controls the cell and contains genetic material
• what is the role of mitochondria

  they produce energy for the cell
• why is smaller cell size more efficient?

  a smaller cell has larger surface area relative to its volume, allowing beter exchange of materials
• what is the cell membrane primarily made of?

  a phospholipid bilayer
• what is the role of cholesterol in the cell membrane?

  it helps control the fluidity and flexibility of the membrane
• what are the two types of membrane proteins?

  integral proteins and peripheral proteins
• what is passive transport?

  the movement of molecules across a membrane without energy, such as diffusion
• what is active transport?

  the movement of molecules against a concentration gradient using energy
• what is osmosis?

  the diffusion of water across a selectively permeable membrane
• what is the difference between simple and facilitated diffusion?

  simple diffusion doesn't require proteins, while factilated diffusion uses channel or carrier proteins
• what is endocytosis?

  the process by which a cell takes in large molecules by engulfing them in a membrane
• what is exocytosis?

  the process by which a cell expels materials in verticals that merge with the cell membrane
• what happens to a cell in a hypertonic solution?

  the cell loses water and shrinks (crenation in animal cells, plasmolysis in plant cells)
• what happens to cells in a hypotonic solution?

  the cell gains water and may swell or burst (lysis in animal cells, turgid in plant cells)
• what are the stages of the cell cycle

  G1, S, G2, M
• what are the stages of mitosis?

  prophase, Metaphase, anaphase, telophase
• what is the difference between mitosis and meiosis?

  mitosis results in two identical diploid cells, while meiosis results in four genetically unique haploid cells
• what is crossing over and in which process does it occur?

  crossing over is the exchange of genetic material between homeologous chromosomes during prophase 1 and meiosis
• what is mitosis

  cell divides to make two identical cells, each with same number of chromosomes os og cell. helps with growth and repair.
• what is meiosis?

  cell divides to make four cells, each with half the number of chromosomes. used for reproduction