Biology 9700 · AS & A Level · Structure of transport tissues

Structure of transport tissues — practice question

Cellulose is a polysaccharide. Fig. 5.1 depicts three sub-units taken from one cellulose molecule.
(a(i))[1]

Name the sub-unit molecule in cellulose.

(a(ii))[1]

Name the bonds that connect the sub-unit molecules together in cellulose.

(b)[2]

Explain why cellulose has such high mechanical strength that it is suitable for plant cell walls.

(c)[4]

Use the labelled parts in Fig. 5.2 to match each statement below to the correct cell structure. You must give just one letter for each one. A letter may be used once, more than once, or not at all. Statements: - organelle that contains DNA (first answer completed for you) - transports cell wall material to the cell surface membrane - site of transcription - site of ribosome synthesis - site of photosynthesis

(d)[3]

Enzymes called expansins are found in the matrix of cell walls and help cells grow. Using the information in Fig. 5.2, describe how proteins made by the ribosomes are delivered to the matrix of the cell wall.

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