Biology 9700 · AS & A Level · Control and coordination in mammals
Control and coordination in mammals — practice question
In mammals, sensory receptor cells detect stimuli and produce action potentials in sensory neurones.
On the human tongue, taste buds contain chemoreceptor cells. Different chemoreceptor cells are sensitive to different chemical stimuli.
Fig. 6.1 shows a diagram of chemoreceptor cells in a taste bud.
(a)[3]
Name the structures in region Y and describe what they do in a chemoreceptor cell.
(b)[6]
When a sugar molecule attaches to a receptor protein on the cell surface membrane of cell A, the endoplasmic reticulum releases calcium ions into the cell cytoplasm. Explain how the release of calcium ions will result in an action potential being generated in sensory neurone B.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Microvilli / brush border extensions” …