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Subdecks (3)

Cards (36)

  • Describe how the nervous system enables the body to respond to stimuli. Include in your answer the roles of sensory neurons, motor neurons, and synapses in transmitting signals.
    • the stimuli are detected by receptors(in the skin or eyes)
    • the sensory neurones transmit electrical impulses to the CNS
    • the brain processes the information and sends a response via motor neurones
    • motor neurones carry carry impulses to effectors(muscles, glands)
    • synapses transmit electrical impulses via neurotransmitters
    • reflex arcs can bypass the brain for rapid responses(involuntary)
  • Explain how cells become specialised for specific functions. Include in your answer the roles of root hair cells, sperm cells, and red blood cells, and how their structure relates to their function.
    • Root hair cells are specialised for water and mineral absorption
    • Sperm cells have a long tail for movement, mitochondria for energy and an acrosome for fertilising the egg
    • Red blood cells are biconcave to increase surface area and lack a nucleus to carry more haemoglobin
    • Specialised cells have structures adapted to their functions
    • Specialisation occurs during development
  • Explain how the structure of alveoli is adapted for efficient gas exchange.
    • Alveoli have a large SA due to their spherical shape which increases the area for gas exchange
    • Alveoli are one cell thick, providing a short diffusion distance for gases
    • Alveoli are surrounded by a network of capillaries, allowing for a rich blood supply and maintaining a concentration gradient
    • moist walls allowing gases to diffuse more easily
    • large SA ensures that oxygen can be absorbed into the bloodstream and carbon dioxide can be expelled
  • Describe the process of osmosis in plant cells and explain how it affects the cell's turgidity? PART 1
    • Osmosis is the movement of water molecules from a high concentration to a low concentration across a semi-permeable membrane
    • In plant cells, water enters the cell through the cell membrane by osmosis when the surrounding solution is hypotonic(low conc of solutes than cell)
    • As water enters, the cell vacuole fills up, and the cells swells
  • What does the cell wall prevent in plant cells?
    It prevents the plant cell from bursting
  • What is turgor pressure in plant cells?
    Pressure of the vacuole against the cell wall
  • What does turgidity refer to in plant cells?
    State of being full of water
  • How does turgidity affect a plant's structure?
    It results in the cell being swollen and firm
  • What happens to a plant cell in a hypertonic solution?
    Water leaves the cell, causing plasmolysis
  • What is the result of a vacuole shrinking in a plant cell?
    The cell membrane pulls away from the cell
  • What is the state of a plant cell when it becomes flaccid?
    The cell loses turgor pressure and firmness
  • What is the effect of a hypertonic solution on plant cells?
    It causes the cells to become plasmolysed
  • What does it mean for a plant cell to be plasmolysed?
    The cell membrane pulls away from the cell wall
  • How does osmosis affect the turgidity of plant cells?
    Osmosis regulates water movement, affecting turgidity