Biology paper 1

• What are the two main types of cells?

  Prokaryotes and Eukaryotes
• What is the function of the cytoplasm?

  It is a gel-like substance where reactions happen and contains enzymes.
• What does the nucleus contain?

  The genetic material for the cell.
• Where do most aerobic reactions take place in a cell?

  In the mitochondria.
• What is the role of respiration in cells?

  It transfers energy that the cell needs to work.
• What is the function of ribosomes?

  They are where proteins are made in the cell.
• What is the composition of the cell wall in plant cells?

  Cellulose.
• How does a bacteria cell wall differ from a plant cell wall?

  Bacteria cell walls are simple layers and not made of cellulose.
• What is a plasmid?

  An extra circular strand of DNA in bacteria cells.
• What is the maximum magnification of a light microscope?

  2000x.
• How does an electron microscope differ from a light microscope?

  It uses electrons instead of light to form an image.
• What is the maximum magnification of an electron microscope?

  2,000,000x.
• What is the resolution limit of an electron microscope?

  0.1 nm.
• How do you calculate magnification?

  Magnification = image size / real size.
• What are the steps in the required practical for observing onion cells under a microscope?

  1. Add a drop of water to a clean slide.
  2. Cut up an onion and peel off epidermal tissue layers.
  3. Place the epidermal tissue into the water on the slide.
  4. Add a drop of iodine solution to highlight the cells.
  5. Place a cover slip over the specimen.
• What is the function of the eyepiece in a light microscope?

  It allows you to view the specimen.
• What is cell differentiation?

  It is the process in which a cell changes to become specialized for its job.
• What is the primary function of sperm cells?

  To get the male DNA to the female DNA.
• How is a sperm cell adapted for its function?

  It has a long tail and a streamlined head to help it swim to the egg.
• Why do sperm cells have many mitochondria?

  To provide the energy needed for movement.
• What is the role of acrosomes in sperm cells?

  They contain digestive enzymes to penetrate the egg cell membrane.
• What are the stages of cell specialization during development?

  1. All cells start as undifferentiated.
  2. As the organism develops, cells differentiate.
  3. Specialized cells can carry out specific functions in tissues, organs, or the whole organism.
• What is the function of nerve cells?

  To carry signals from one part of the body to another.
• How are nerve cells adapted for their function?

  They are long and have branched connections to cover more distance.
• What is the function of muscle cells?

  To contract and cause movement.
• How are muscle cells specialized for contraction?

  They are long and contain many mitochondria to generate energy.
• What is the role of root hair cells?

  To absorb water and minerals from the soil.
• How do root hair cells increase absorption efficiency?

  They have long extensions that increase surface area.
• What are phloem and xylem cells specialized for?

  Transporting substances such as food and water around plants.
• How do phloem and xylem cells form tubes?

  They are long and joined end to end.
• What is unique about xylem cells?

  They are hollow in the center.
• What is unique about phloem cells?

  They have very few subcellular structures so sugar can flow through them.
• What are stem cells?

  • Undifferentiated cells
  • Can develop into specialized cells
  • Important for growth and repair
• Pathogen

  A microorganism that causes disease in animals, including humans.
• How do pathogens cause disease?


  Toxin production, Invasion, Immune system suppression, Nutrient competition
• Photosynthesis


  The process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose.