A student places thin sections of leaf tissue containing palisade cells into separate dishes of sucrose solution. A different sucrose concentration is used in each dish. After treatment, the student records whether the cell membrane has pulled away from the cell wall.
Which action would control a variable in this investigation?
Use tissue from a different leaf at each concentration.
Leave tissue for longer in the more dilute solutions.
Count the cells in each section whose membrane has pulled away.
Put the same volume of sucrose solution in every dish.
194 exam-style questions on OCR GCSE Biology 2.1 Supplying the cell, covering 2.1.1 Transport across cell membranes, 2.1.2 Mitosis and the cell cycle, 2.1.3 Importance of cell differentiation, and 2.1.4 Stem cells. Each one has a worked solution and a mark scheme showing where the marks go.