Biology Question (A-Level)

Practising exam papers over and over again and then reading mark schemes, self marking and learning required terminology should help. You also need to make sure certain terms are spelt correctly e.g. protoctista.

When describing the cardiac cycle, begin writing about diastole (ventricles and atria relaxing), then go on to say about atrial systole and further on to ventricular systole etc.

You find carrier proteins and channel proteins in the phospholipid bilayer, and they allow for transport via facilitated diffusion. Channel proteins form pores in the membrane and are often shaped to allow only one type of ion through+many are gated, so can open and close. Carrier proteins are shaped for specific molecules such as glucose to fit into them at the membrane surface and the protein changes shape when the molecule fits, to allow if through the other side of the membrane.