Grade 9 whole of bio

• Who is the expert examiner mentioned in the video?

  Lauren
• What is the function of the cell membrane?

  To control the entry and exit of substances into the cell
• What is the largest structure inside an animal cell?

  The nucleus
• What is the function of ribosomes?

  To carry out protein synthesis
• What is the function of mitochondria?

  To carry out aerobic respiration and provide energy for the cell
• What is the function of chloroplasts in plant cells?

  To absorb light energy for photosynthesis
• What is the main difference between plant and animal cells?

  Plant cells have a cell wall, vacuole, and chloroplasts, while animal cells do not
• What type of cells are both plant and animal cells classified as?

  Eukaryotic cells
• What does the term 'prokaryotic' mean?

  Cells that do not have a nucleus
• Where is the DNA located in prokaryotic cells?

  In the cytoplasm, floating around
• What is a flagellum used for in some bacterial cells?

  For movement or swimming
• What is the function of plasmids in bacterial cells?

  They often contain useful genes like antibiotic resistance
• What is the main similarity between prokaryotic and plant cells?

  Both have a cell wall
• What is the process called when cells become specialized?

  Differentiation
• What are root hair cells specialized for?

  To absorb water and mineral ions from the soil
• What is the function of xylem in plants?

  To transport water
• What is the function of phloem in plants?

  To transport sugars and amino acids
• What is the main function of sperm cells?

  To swim to the egg for fertilization
• What is the role of mitochondria in muscle cells?

  To provide energy for contraction
• What are stem cells?

  Undifferentiated cells that can produce different cell types
• What is the difference between embryonic and adult stem cells?

  Embryonic stem cells can differentiate into nearly any type of cell, while adult stem cells can only differentiate into some types
• What is therapeutic cloning used for?

  To produce embryonic stem cells that are genetically identical to the patient
• What is diffusion?

  The net movement of particles from an area of high concentration to an area of low concentration
• What are the main components of an animal cell and their functions?

  • Cell membrane: controls entry and exit of substances
  • Cytoplasm: where chemical reactions happen
  • Ribosomes: protein synthesis
  • Nucleus: controls cell activities
  • Mitochondria: aerobic respiration and energy production
• What are the main components of a plant cell and their functions?

  • Cell wall: provides structure and support
  • Cell membrane: controls entry and exit of substances
  • Cytoplasm: where chemical reactions happen
  • Ribosomes: protein synthesis
  • Nucleus: controls cell activities
  • Mitochondria: aerobic respiration and energy production
  • Chloroplasts: absorb light energy for photosynthesis
  • Permanent vacuole: supports cell structure
• What are the differences between prokaryotic and eukaryotic cells?

  Differences:

  • Prokaryotic cells do not have a nucleus; eukaryotic cells do.
  • Prokaryotic cells lack mitochondria and chloroplasts; eukaryotic cells have them.
  • Prokaryotic cell walls are not made of cellulose; eukaryotic plant cell walls are.
• What is the process of differentiation in cells?

  • Cells become specialized through differentiation.
  • Different genes are turned on or off.
  • Changes in shape and number of subcellular structures occur.
• What is the significance of stem cells in development?

  • Stem cells are undifferentiated and can become various cell types.
  • They are crucial in early development and tissue repair.
  • Adult stem cells have limited differentiation potential compared to embryonic stem cells.
• What are the steps to prepare a microscope slide?

  1. Add a drop of water to the slide.
  2. Place a thin piece of tissue on the slide.
  3. Stain the tissue (e.g., with iodine).
  4. Lower a cover slip gently over the tissue.
  5. Place the slide on the microscope stage.
• What is the formula to calculate bacterial growth through binary fission?

  • Formula: Number of bacteria = Initial number × \(2^{\text{number of divisions}}\)
• What are the ethical issues surrounding embryonic stem cell use?

  • Consent issues: embryos cannot consent.
  • Potential life concerns: destruction of unused embryos.
  • Risks of viral infection and cancer from rapid cell division.
• What type of cells can be grown to treat paralysis after cancer treatment?

  Nerve cells or nerve tissue
• Why are there ethical issues surrounding the use of embryonic stem cells?

  Because the embryo cannot consent to be used
• What is a concern regarding the destruction of unused embryos in stem cell research?

  Some people believe it is not acceptable as the embryo represents potential life
• What is a risk associated with using stem cells from another person?

  There is a risk of viral infection transfer
• What is diffusion?

  Diffusion is the net movement of particles from an area of high concentration to an area of low concentration
• What types of molecules primarily diffuse into cells?

  Oxygen and glucose
• What waste products diffuse out of cells?

  Carbon dioxide and urea
• What are the four factors that affect the rate of diffusion?

  Concentration gradient, distance, temperature, and surface area
• How does increasing the concentration gradient affect diffusion?

  It increases the speed of diffusion