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Flashcards · Biology · Cell Structure

Cell Specialisation and Differentiation

20 cards

  1. What is a specialised cell?

    A cell with a structure that is suited to its particular job.

  2. What is differentiation?

    The process by which a cell changes to become specialised.

  3. Why does a sperm cell have a long tail?

    So it can swim to the egg.

  4. Why does the middle of a sperm cell contain many mitochondria?

    They release the energy needed for swimming.

  5. What is the job of the acrosome?

    It contains enzymes that digest the outer layer of the egg so the sperm can get in.

  6. How is a nerve cell adapted to carry impulses over long distances?

    It has a long axon, and a myelin sheath that insulates it.

  7. Why do nerve cells have branched dendrites?

    They connect to many other nerve cells.

  8. What do muscle cells contain that lets them contract?

    Special protein fibres that slide over each other, and many mitochondria for energy.

  9. How does the shape of a root hair cell help it?

    The long projection gives a large surface area to absorb water and minerals.

  10. Why do root hair cells have a large permanent vacuole?

    It speeds up the movement of water into the cell.

  11. What does xylem transport?

    Water and mineral ions, from the roots up to the leaves.

  12. Why is xylem strengthened with lignin?

    The rings stop the hollow tube collapsing and make it strong.

  13. What does phloem transport?

    Dissolved sugars to wherever they are needed.

  14. What are sieve plates?

    The walls between phloem cells, with holes that let sugars flow through.

  15. What is the job of companion cells in phloem?

    Their mitochondria supply the energy for moving sugars.

  16. Do animal cells or plant cells keep the ability to differentiate throughout life?

    Plant cells. Most animal cells differentiate early.

  17. Put these in order, smallest first: organ, cell, tissue, organism.

    Cell, tissue, organ, organism.

  18. A sperm cell with a pointer marked X to the middle section. Name the part marked X on this sperm cell, and explain why it is there.

    Mitochondria in the middle section. They release the energy from respiration that the tail needs for swimming.

  19. A nerve cell with a pointer marked X to a segment of the myelin sheath. Name the part marked X on this nerve cell and say what it does.

    The myelin sheath. It is a fatty layer that insulates the axon and speeds up the impulse.

  20. A root hair cell with a pointer marked X to the long root hair. What is the structure marked X on this root hair cell, and how does it help?

    The root hair. Its long, thin shape gives a large surface area for absorbing water and mineral ions from the soil.