DNA Replication

• State the two types of cell division.

  Mitosis and Meiosis.
• What is mitosis?

  Cell division which produces two daughter cells which have the same number of chromosomes as the parent cell, both are genetically identical.
• What is meiosis?

  Cell division which produces four daughter cells each with half the number of chromosomes as the parent cell and are all genetically different.
• What is meant by the term gene mutation?

  A change in the order or number of nucleotides in a gene.
• What joins two chromatids together in a chromosome?

  Centromere.
• What occurs during interphase of mitosis?

  The cell carries out normal cellular activity including G1, S, and G2 phases.
• What occurs during during G1 phase?

  The cell grows to its normal size after the previous division.
• What occurs during S phase?

  The cell undergoes DNA replication.
• What occurs during G2 phase?

  The cell produces new organelles specific for division.
• What occurs during prophase of mitosis?

  Chromosomes condense and become visible. Centrioles start to move to the poles of the cell. Centrioles start to form spindle fibres.
• What occurs during metaphase of mitosis?

  The chromosomes are pulled using spindle fibres to the equator of the cell.
• What occurs during anaphase of mitosis?

  The centromere divides, the spindle fibres get shorter and the chromatids move to the opposite poles of the cell.
• What occurs during telophase of mitosis?

  The chromatids unravel and the nuclear envelope reforms.
• What is binary fission?

  Cell division in prokaryotic cells.
• What is meant by the term cytokinesis?

  Division of the cytoplasm to produce 2 cells.
• State the importance of mitosis.

  -Growth of new tissues.

  -Repair of tissues.

  -Reproduction of single celled eukaryotes.

  -Asexual reproduction.
• What do viruses use to enter the host cell?

  Attachment proteins.
• What do viruses inject into the host cell?

  DNA/RNA and enzymes.
• What is meant by the term haploid?

  When a cell only has one copy of each chromosome.
• What is meant by the term diploid? 


  When a cell has 2 copies of each chromosome.
• What is meant by the term cancer?

  Uncontrolled cell division.
• State two ways that cancer cells can be treated.


  Preventing DNA from replicating. Inhibiting spindle formation during metaphase.