Cell Division

Cards (39)

  • Chromosome formation
    DNA strands form chromosomes when cells prepare to divide
  • Cell cycle stages

    1. Growth and DNA replication
    2. Mitosis
    3. Cell division
  • Stem cells
    Undifferentiated cells capable of becoming other types of cells, undergoing a process known as differentiation
  • The Cell Cycle
    A) growth and DNA replication
    B) mitosis
    C) cell division
    • When cells are in their normal states, the DNA in the nucleus exist in the form of LONG STRANDS.
    • When cells prepare to divide, the strands of DNA form CHROMOSOMES.
  • CHROMOSOMES
    structures within the nucleus of cells containing tightly coiled DNA.
    • Human body cells have 46 CHROMOSOMES, which exists as 23 PAIRS, where each pair is inherited from each parent.
    • Sex Cells (known as GAMETES) have HALF the number of chromosomes (23), and when a sperm cell fertilises an egg cell, the two halves join to form a full set of 46 Chromosomes.
    • Each chromosome holds numerous GENES responsible for various PHYSICAL CHARACTERISTICS like hair colour and eye colour.
  • The CELL CYCLE,
    a series of events that cells go through to grow and DIVIDE, with the result of the formation of 2 cells that are IDENTICAL to the original cell, which was known as DAUGHTER CELLS.
    A) daughter cells
  • The cell cycle
    A) growth dna replication
    B) mitosis
    C) cell division
    1. Growth and DNA Replication
    The cell increases its SUBCELLULAR STRUCTURES, such as mitochondria and ribosomes.
    • The nucleus of the cell REPLICATE their DNA, forming two identical x-shaped chromosomes
  • 2. Mitosis
    The MEMBRANE of the nucleus breaks down
    • The Chromosomes align in the CENTRE of the cell and are then pulled apart to opposite ends of the cell by structures known as CELL FIBRES.
  •  3. Cell Division
    New membranes form around each set of chromosomes to form TWO NUCLEI
    • The cytoplasm and cell membrane SPLIT to form TWO IDENTICAL DAUGHTER CELLS
  • chromosomes
    When the cell starts to divide, strands of DNA (genetic material) found in the nucleus coil/form into chromosomes, which carries thousands of genes.
  • The cell cycle
    The cell grows and chromosomes duplicate.
    Then one set of chromosomes is pulled to each end of cell by cell fibres.
    Two nuclei forms from that.
    Cytoplasm & membrane divides (Cytokinesis) to form two identical cells.
  • describe how mitosis produces two genetically identical cells.
    When the chromosomes is doubled, it gets pulled apart from cell fibre, then two new nuclei form and each new cell has the same set of genes.
  • 35 %
  • Describe what's happening in the photo.
    cytoplasm and cell membrane dividing to form two identical daughter cells.
  • The cell cycle makes new cells for:
    • growth and development of multicellular organisms
    • repairing damaged tissues
    • asexual reproduction
    • Stem cells are UNDIFFERENTIATED cells that can differentiate into other cell types
    1. Stem cells found in early HUMAN EMBRYOS, have the potential to turn into ANY cell type.
  • 2. ADULT STEM CELLS exist too but are limited in the types of cells they can turn into. Are commonly found in BONE MARROW and can only differentiate into different types of BLOOD CELLS (eg. Red blood cells and White blood cells).
  • STEM CELLS can be grown in labs and differentiated into specialised cells for MEDICINE or RESEARCH.
    • ADULT STEM CELLS can be used to treat diseases by replacing faulty BLOOD CELLS in patients.
    • EMBRYONIC STEM CELLS have potential in treating a variety of conditions, including DIABETES and SPINAL INJURIES.
    • THERAPEUTIC CLONING involves creating embryos with the same DNA as a patient, which can be used to produce stem cells with the same genetic information as the patient, to reduce risks of REJECTION.
    • In plants, stem cells are found in MERISTEM TISSUE, which are on the TIPS of plant shoots and roots where growth occurs.
  • plant stem cells can differentiate into ANY type of plant cell.
  • Plant stem cells can be used to produce identical CLONES of plants, this is useful for preserving RARE SPECIES of plant and producing CROPS with desirable traits like DISEASE and INSTECTICIDE RESISTANCE.
  • stem cells can differentiate, therefore can form heart cells.
    1. Adult can give consent
    2. cells will not be rejected
    • it can treat diseases.
    • cells of any type can be produced
    • would reduce waiting time of transplants
    • cells unlikely to be rejected by patient
    • many cells produced
  • suggest two disadvantages of therapeutic cloning.
    • shortage of donors
    • egg donation has risks
  • bone marrow cells differentiate into many types of blood cells, so will cure diseases where cells are damaged.
  • Embryos advantages:
    • can create many embryos in a lab
    • painless technique
    • can treat many diseases
    Disadvantage
    • may not work
  • Bone marrow advantages:
    • patient can give permission
    • can treat some diseases
    • reliable technique
    • patients recover quickly from procedure
    Disadvantages:
    • risk of infection from procedure
    • can only treat a few diseases
    • procedure can be painful
  • embryos and bone marrow advantage:
    • can treat the disease
    disadvantage:
    • risk of transfer of viral infection
    • some stem cells become cancerous.