4.6.1.2 meiosis

• What is meiosis?

  a type of cell division that produces gametes with half the number of chromosomes as the parent cell.
• in meiosis how many cells are made from the original cell?

  four
• what is the first stage meiosis?

  the cells duplicates its genetic information
• what happens after the genetic information is replicated?

  the chromosomes arrange themselves in pairs at the centre of the cell
• What happens after the chromosomes arrange themselves into pairs?

  The pairs are pulled apart so each new cell has one copy of the chromosone
• what happens in the second division?

  the chromosomes line up at the centre again and the arms of the chromosomes are pulled apart
• What are all the gametes?

  Genetically different
• what happens to the gametes at fertilisation?

  they join to restore the normal number of chromosomes
• what happens to the new cell made after fertilisation?

  the new cell divides by mitosis to make a copy of itself
• how many times does mitosis repeat and why?

  many times to prodcue lots of new cells in an embryo
• what happens to the cells as the embryo develops?

  differentiation