(a)[3]
Use label lines and the letters C to E to identify the following on Fig. 6.1. C - a structure involved in ribosome synthesis. D - an organelle involved in the modification and packaging of proteins. E - an organelle involved in aerobic respiration.
(b)[4]
The concentration of sucrose in the sap of the phloem sieve tube element is much higher than the concentration in the cytoplasm of the photosynthesising cell. Describe and explain how sucrose is moved from the photosynthesising cell into the phloem sieve tube element.