page 11 14. An investigation was carried out into the social hierarchy in a group of five hens, V, W, X, Y and Z. Hens establish dominance by pecking each other aggressively. The number of pecks given and received was recorded. The results are shown in the table. Number of pecks given by each hen V W X Y Z Number of pecks received by each hen V - - - 10 - W 2 - - 13 - X 6 8 - 7 - Y - - - - - Z 11 10 5 4 - The order of hierarchy from most dominant to least dominant hen is A Z, V, X, W, Y B Y, V, W, X, Z C Z, X, W, V, Y D Y, W, V, X, Z. 15. Each type of human cell has a different structure and function because A only some of their genes are expressed B they contain different genes C some genes are lost during differentiation D some genes are gained during differentiation. [Turn over