BIOLOGY paper 1

• What contains genetic information in the nucleus

  Chromosomes
• What do chromosomes contain


  Genetic information in the nucleus
• What is mitosis


  Growth and repair
• How many copies do body cells have

  2
• Is diploid cells 4 or 2 copies

  2
• Cells divide by mitosis to make what?

  2 identical cells
• 2 new cells are always what?

  Identical
• How many stages of cell division are there?

  5
• What are the stages of cell division in mitosis


  Interphase propose metaphase anaphase telephone (cytokinesis)
• Explain interphase


  DNA spreads out into long strings
• Explain prophase


  Chromosomes double and get into pairs,membrane breaks down
• Explain metaphase


  Chromosomes line up in the middle of the cell
• Explain anaphase

  Cell fibres pull the chromosomes apart towards opposite ends of the cell
• Explain Telophase


  Membrane forms around each set of chromosomes and become the nuclei of 2 new cells
• Explain cytokinesis


  Cytoplasm and cell membrane divide to form 2 separate cells
• What happens at the end of mitosis

  The cell produces 2 new daughter cells
• What's it called when 2 cells are genetically identical?

  Diploid cells
• What grows fast when young and older?


  Animals
• Where does cell division happen in plants?

  Meristem
• What is made by plant cell division?

  Xylem and phloem
• What is cancer?


  Uncontrolled cell division
• What is uncontrolled cell division?

  Cancer
• Where are stem cells found?

  Human embryos or bone marrow
• What are stem cells important for

  Growth and development
• Define stem cell


  Stem cells are a cell that has no purpose for the human body YET
• What can stem cells be used for?

  To treat certain conditions
• What's another word for identical?

  Aesexual or
• What is meiosis?


  Cell division that produces gametes
• How many is a haploid?

  4
• Where does meiosis occur?

  Reproductive organs
• What are the reproductive organs?

  Ovaries and testes
• What is fertilisation?

  Sperm and egg fuse to form zygote
• Is meiosis identical or variation?

  Variation(4 different genetic cells)
• What is the shape of DNA?

  double helix
• How many strands is a double helix

  2
• Does DNA have weak or strong hydrogen bonds?

  Weak hydrogen bonds
• What are the complimentary pairs of DNA

  A-T and C-G
• what is DNA stored as?

  Chromosomes
• Where is chromomes of dna found?

  Nucleus of eukaryotic cells
• What is a gene?

  Section of DNA