To protect vulnerable 16 and 17 year olds, the offences of 'abuse of a position of trust' prohibits sexual contact between adults and children under 18 in schools, colleges and residential care.
Chromosome abnormalities usually happen as a result of an error in cell division. Meiosis is the name used to describe the cell division that the egg and sperm undergo when they are developing. Normally, meiosis causes a halving of chromosome material, so that each parent gives 23 chromosomes to a pregnancy.
Mitosis is cell division that results in the duplication of cells; daughter cells that are exact copies of the parent cell, with the same number of chromosomes. In mitosis, the genetic material duplicates and then divides, so that each new cell has the same genetic instructions as the parent cell did.