1. Cell Biology

• What are the two main types of cells?

  Prokaryotic and eukaryotic
• What is the key difference between prokaryotic and eukaryotic cells?

  Prokaryotes lack a nucleus and membrane-bound organelles, while eukaryotes have a nucleus and organelles
• What is cell specialization?

  The process by which cells become specialized to perform specific functions
• What is an adaptation of a nerve cell that helps it transmit signals?

  Long axons
• What are the main stages of mitosis?


  Interphase, prophase, metaphase, anaphase, telophase, cytokinesis
• During which stage of mitosis do chromosomes line up at the cell's equator?

  Metaphase
• What are the 3 main types of cellular transport?

  Diffusion, osmosis, active transport
• Which type of cellular transport requires energy from the cell?

  Active transport
• What are the two main types of stem cells?

  Embryonic and adult
• Which stem cells have greater differentiation potential?

  Embryonic stem cells
• What is diffusion in the context of cell transport?

  Diffusion is the passive movement of particles from an area of high concentration to an area of low concentration.
• What are the key characteristics of diffusion?

  Diffusion occurs spontaneously, moves along a concentration gradient, and does not require energy input from the cell.
• Why can't large protein molecules diffuse across cell membranes?

  They are too large to fit through the membrane.
• Name three specific substances transported by diffusion in animal cells.

  Oxygen (O₂), carbon dioxide (CO₂), and water (H₂O).
• Which organelle is the site of anaerobic respiration? 


  Cytoplasm
• Which organelle is the site of protein synthesis?

  Ribosomes
• Which organelle is the site of photosynthesis?

  Chloroplast
• How many chromosomes does a human skin cell contain?

  46
• How many chromosomes does a human gamete contain?

  23
• How does the acrosome help the sperm cell to carry out its function?

  The acrosome, in the tip, releases the necessary enzymes to digest through the egg cell membrane.
• Why do cells undergo mitosis?

  • so cells can grow
  • so cells can be replaced
  • to repair damaged tissue
• What happens to the cell during mitosis?

  • nucleus disappears and chromosomes line up at the centre of the cell
  • cell fibers pull the 2 identical arms of each chromosome apart and towards opposite poles of the cell
  • a new nucleus forms around each set of chromosomes
  • cytoplasm divides forming 2 identical daughter cells
• What are embryonic stem cells?

  Cells removed from the embryo that have totipotency (potential to become any cell type)
• Name 2 medical conditions that could be treated with embryonic stem cells in the future.

  • Diabetes
  • Paralysis
• How could you prepare an uncontaminated culture of bacteria using the aseptic technique?

  • sterilise petri dishes and surfaces before use
  • sterilise inoculating loop by passing it through a hot flame
  • tape lid onto petri dish after transferring bacteria to prevent contamination from microorganisms in the air
• What is diffusion? 


  The spreading out of the particles of any gas or liquid from an area of high concentration to an area of lower concentration.
• Name 3 substances that are transported into or out of animal cells by diffusion.

  • Oxygen
  • Carbon dioxide
  • Amino acids
• What is the purpose of the objective lens in the light microscope?

  To form and magnify an image of the specimen.
• Name the tubes that transport water up the stem of a plant by transpiration. 


  Xylem
• What is osmosis? 


  The movement of a solvent (eg: water) from an area of high concentration to a lower concentration through a semi-permeable membrane.
• Describe an advantage of using therapeutic cloning to treat disease.

  An embryo is made to have the same genetic information as the patient, so stem cells from it would contain the same genes and wouldn’t be rejected by the patient’s body.
• Which organelle is the site of aerobic respiration? 


  Mitochondria
• Which organelle controls the movement of substances in and out of the cell?

  Cell membrane
• Which organelle contains the genetic information? 


  Nucleus
• What is the cytoplasm? 


  A gel-like substance where chemical reactions happen. It contains enzymes that control these reactions.
• How does the ability to differentiate differ between plant cells and animals cells?

  The ability to differentiate is lost at an early stage in most animal cells (after they have become specialised), but lots of plant cells don’t ever lose this ability.
• What is the function of xylem cells and how are they specialised for this function?

  Xylem cells transport water and minerals up plants. They are specialised for their function as the cells are long and are joined end to end, forming hollow tubes. This means that substances can flow through them.
• What is the function of a nerve cell and how is a nerve cell adapted for its function?

  A nerve cell carries electrical impulses (signals) from one part of the body to another. The cell is long and has branched connections (axons) at its ends to connect to other nerve cells and form a network throughout the body. This allows for rapid signalling.
• What is a stem cell?

  An undifferentiated cell which has the ability to become one of many different types of cell or more stem cells