1. 1
   A commercial plant nursery is comparing different cloning methods to decide which is best for propagating a rare orchid species quickly and in large numbers.

   (a)

   A commercial plant nursery takes small groups of cells from a rare orchid and grows them on a nutrient medium to produce large numbers of genetically identical plants. Which cloning technique is being used?

   [1 mark]

   • ATissue culture
   • BEmbryo transplant
   • CAdult cell cloning
   • DTaking cuttings

   (b)

   The nursery manager also considers simply cutting sections of stem from a parent orchid and planting them directly in soil to grow into new plants. Why is this method generally considered simpler than tissue culture, even though it usually produces fewer plants per parent plant?

   [1 mark]

   • AIt requires a sterile nutrient medium and laboratory equipment
   • BIt does not require specialist laboratory equipment or a nutrient medium
   • CIt produces genetically varied offspring rather than clones
   • DIt only works with animal tissue, not plant tissue

   (c)

   The nursery manager decides to use tissue culture for large-scale production but keeps a few cuttings as a backup method. Suggest two reasons why a plant business might want to use more than one cloning method rather than relying on tissue culture alone.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A livestock breeder is investigating different ways of cloning cattle, and later considers using adult cell cloning to reproduce a prize-winning cow with valuable characteristics.

   (a)

   A livestock breeder wants to produce several genetically identical calves from one high-quality embryo before any of the cells have become specialised. Which cloning technique should be used?

   [1 mark]

   • ATissue culture
   • BGenetic engineering
   • CTaking cuttings
   • DEmbryo transplant

   (b)

   The breeder later asks a laboratory about adult cell cloning to reproduce the prize-winning cow. In this technique, what is inserted into an unfertilised egg cell after its own nucleus has been removed?

   [1 mark]

   • AA whole embryo from a different cow
   • BA nucleus from a sperm cell of a different cow
   • CA nucleus from an adult body cell of the cow, such as a skin cell
   • DA bacterial plasmid containing the cow's genes

   (c)

   After the nucleus from the cow's skin cell has been inserted into the empty egg cell, describe what happens next for adult cell cloning to produce a calf that is genetically identical to the prize-winning cow.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A biotechnology company is developing genetically engineered organisms, first bacteria to produce human insulin, and separately a crop plant modified to resist attack by insects.

   (a)

   A biotechnology company wants to produce human insulin using genetically engineered bacteria. Describe the steps involved in inserting the human insulin gene into a bacterial cell so that the bacteria can produce insulin.

   [3 marks]

   (b)

   The same company also develops a crop plant with a gene inserted at an early stage of development so that the mature plant is resistant to attack by a particular insect pest. Explain why the gene must be inserted at an early stage of the plant's development for every cell of the mature plant to show insect resistance.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A farming cooperative is deciding whether to switch from a conventional herbicide-resistant crop to a genetically modified (GM) version of the same crop, which the seed supplier claims gives a higher yield.

   (a)

   Using the information given, explain the reasons a farmer might choose to grow GM crops and discuss the concerns that have been raised about growing GM crops, so that the cooperative can make an informed judgement.

   [6 marks]

   (b)

   A member of the cooperative suggests that, instead of using GM crops, they should clone their best-performing conventional plants using tissue culture to keep improving yields. Evaluate whether tissue culture cloning could achieve the same benefits as switching to a GM crop, and explain a key difference between what each technique can achieve.

   [6 marks]

   Total for question 4: 12 marks

End of questions