A gardener grows a species of dahlia, a flowering plant. Each year the gardener chooses his best plants and takes cuttings to make new plants. shoots are cut (cuttings) and their lower leaves removed the cut ends are placed into well-watered soil and covered by a transparent plastic bag single dahlia plant the cut ends grow roots and the cuttings develop into new plants

1. (a)(i)Removing the lower leaves and placing the cuttings in a transparent bag helps prevent them wilting until the roots develop. Suggest and explain how these two steps help to prevent wilting. removal of lower leaves covering with transparent bag[3]
2. (a)(ii)Taking cuttings is a commercial application of asexual reproduction. Define asexual reproduction.[2]
3. (b)The stems of the dahlia cuttings contain xylem vessels. Describe two functions of xylem vessels in young stems of dahlias. For each function explain one way in which xylem structure is adapted for this function. function 1 adaptation function 2 adaptation[4]
4. (c)The gardener's dahlia cuttings grow into full-sized plants with flowers. The gardener decides that he would like to produce a plant that combines the disease-resistant characteristics of one of these plants with the red petal colour of another. With reference to named parts of the flowers, describe how he could achieve this.[5]

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