Biology 9700 · AS & A Level · Structure of transport tissues
Structure of transport tissues — practice question
Meristematic tissue occurs in the growing parts of plants, for example the shoot tips. Meristematic cells perform a role comparable to stem cells in animals.
Fig. 4.1 shows several stages in the development of a mature phloem sieve tube element and companion cells from a meristematic cell.
(a)[1]
Cells E and F in Fig. 4.1 are daughter cells formed when the meristematic cell divides in the shoot tip. Explain why it is important for one of the daughter cells (cell E) to remain a meristematic cell.
(b)[3]
Complete Table 4.1 by describing the changes shown in Fig. 4.1 from stages F to G, G to H, and H to J.
(c)[4]
Explain how the structure of a mature sieve tube element is connected to its function.
(d)[2]
Describe the roles of companion cells in transport in the phloem.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Meristems supply cells that divide and differentiate so growth can continue” …