T-helper lymphocytes and Leydig cells are both mammalian cell types. Their principal function is to make and release cell-signalling molecules.
T-helper lymphocytes make proteins called cytokines.
Leydig cells make the steroid (lipid) hormone testosterone from cholesterol. Leydig cells also make cholesterol.
(a)[1]
State one way in which cytokines take part in an immune response.
(b(i))[2]
State, with reasons, whether Fig. 3.1 shows part of a Leydig cell or part of a T-helper lymphocyte.
(b(ii))[2]
Underline the correct name for the type of image shown in Fig. 3.1 and justify your choice.
(c(i))[2]
Outline one way in which testosterone molecules could enter their target cells.
(c(ii))[2]
Cytokine molecules are unable to enter their target cells. Suggest and explain why cytokine molecules are unable to cross the cell surface membrane to enter their target cells.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Any one immune response that is stimulated or suppressed (for example, antibody production, macrophage response, chemotaxis)” …