Peter has a problem with his semicircular canals. this probably means that: a. he cannot speak clearly. b. he has difficulty hearing what is being said. c. he has trouble processing information. d. he has trouble with his balance.

The correct answer is letter D. He has trouble with his balance. This is part of the inner ear that is contains a semi-like fluid inside that is sensitive to movements and motions of the body. Inside these semi-circular canals are hair-like structures that sway or move with the fluids when it detects motion. If there is an imbalance within the membrane, a person may have problems with his balance. A condition that is also known as vertigo.

Many cells are specialised. They have structures that are adapted for their function. For example, muscle cells bring parts of the body closer together. They contain protein fibres that can contract when energy is available, making the cells shorter.