PAPER 1 : CB1 - CB5

• What are the basic units of life?

  Cells
• What is the function of the nucleus in a cell?

  It contains genetic material (DNA) and controls cell activities.
• What is the jelly-like substance where chemical reactions occur in a cell?

  Cytoplasm
• What controls what enters and leaves the cell?

  Cell membrane
• What are the powerhouses of the cell where energy is produced?

  Mitochondria
• What is the site of protein synthesis in a cell?

  Ribosomes
• What additional organelles are found in plant cells but not in animal cells?

  Cell wall, chloroplasts, and vacuole
• What is the main difference between plant and animal cells regarding cell walls?

  Plant cells have a cell wall made of cellulose, while animal cells do not have a cell wall.
• Why do plant cells have chloroplasts while animal cells do not?

  Chloroplasts are present in plant cells for photosynthesis, which is not a function of animal cells.
• What is the significance of a large central vacuole in plant cells?

  A large central vacuole provides storage and helps maintain turgor pressure in plant cells.
• How do the shapes of plant and animal cells differ?

  Plant cells are usually rectangular, while animal cells are often round or irregular.
• What is cell specialization?

  Cell specialization is the process by which cells develop specific structures and functions to perform particular roles in the body.
• What are stem cells?

  Stem cells are unspecialized cells that can develop into various cell types.
• What is differentiation in the context of cells?

  Differentiation is the process of a cell becoming specialized.
• What is the shape of red blood cells and why is it important?

  Red blood cells have a biconcave shape, which allows for a larger surface area for oxygen transport.
• Why do nerve cells have a long and branched structure?

  Nerve cells (neurons) are long and branched for rapid signal transmission.
• What is diffusion?


  Diffusion is the movement of particles from an area of high concentration to low concentration without requiring energy.
• What is osmosis?


  Osmosis is a special type of diffusion involving the movement of water molecules across a partially permeable membrane.
• What is active transport?

  Active transport is the movement of particles against the concentration gradient, requiring energy (ATP).
• What is the function of root hair cells in plants?

  Root hair cells have long projections to increase surface area for water absorption.
• What is facilitated diffusion?


  Facilitated diffusion is the diffusion of specific molecules through protein channels in the cell membrane without requiring energy.
• If a cell needs to move glucose from an area of low concentration to an area of high concentration, which method of transport would be used?

  Active transport
• Which processes require energy from the cell?

  Active transport and protein synthesis require energy from the cell.
• Which process is a passive process that does not require energy from the cell?

  Diffusion
• What happens to a plant cell in a hypertonic solution?

  The cell will lose water and shrink (plasmolysis).
• What are the terms related to osmosis?

  • **Hypotonic**: Lower solute concentration outside the cell
  • **Hypertonic**: Higher solute concentration outside the cell
  • **Isotonic**: Equal solute concentrations inside and outside the cell
• What are the key points about osmosis?

  • Movement of water molecules across a partially permeable membrane
  • From high water concentration to low water concentration
  • Specific to water molecules
  • Important for plant cell turgor and animal cell water balance
• What happens to a plant cell when placed in pure water?

  It becomes turgid but doesn't burst.
• In which type of solution does a plant cell become turgid?

  Hypotonic solution
• What is the definition of cell division?

  Cell division is the process by which a parent cell divides into two or more daughter cells.
• What are the two main types of cell division?

  The two main types of cell division are mitosis and meiosis.
• What is the outcome of mitosis?

  Mitosis results in two genetically identical daughter cells.
• What happens during anaphase of mitosis?

  During anaphase, sister chromatids separate and move to opposite poles of the cell.
• What is the significance of metaphase in mitosis?

  In metaphase, chromosomes align at the cell's equator, ensuring proper separation during anaphase.
• What is cytokinesis?


  Cytokinesis is the division of the cytoplasm, resulting in two separate daughter cells.
• What is differentiation in the context of stem cells?

  Differentiation is the process by which stem cells become specialized cell types, controlled by various factors including genes and environmental signals.
• What happens during the G0 phase of the cell cycle?

  During the G0 phase, cells exit the cell cycle temporarily or permanently and do not actively divide.
• What is the duration of a typical human cell cycle?

  A typical human cell cycle might complete in about 24 hours.
• What is the role of the cleavage furrow in cytokinesis?

  The cleavage furrow forms in animal cells during cytokinesis to help divide the cytoplasm into two daughter cells.
• What is the role of the cell plate in cytokinesis?

  The cell plate forms in plant cells during cytokinesis to help divide the cytoplasm into two daughter cells.