If a team official, substitute, substituted or sent off player or outside agent enters the field of play the referee must: 1  only stop play if there is interference with play. 2  have the person removed when play stops. 3  take appropriate disciplinary action.
The bicarbonate ion (hydrogencarbonate ion) is an anion with the empirical formula H C O 3 â and a molecular mass of 61.01 daltons; it consists of one central carbon atom surrounded by three oxygen atoms in a trigonal planar arrangement, with a hydrogen atom attached to one of the oxygens.
Contain haemoglobin to carry oxygen to the cells. Thin outer membrane to let oxygen diffuse through easily. Shape increases the surface area to allow more oxygen to be absorbed efficiently. No nucleus, so the whole cell is full of haemoglobin. You are likely to be given information, perhaps in a diagram, to help you to explain the adaptations of a particular cell type to its function.