CloningIB MYP Biology: Flashcards

Exam questions on Cloning

1. A tea farm in Kenya has one bush that produces an exceptionally high yield of leaves with a strong flavour. The farm manager cuts short stems from this bush, dips them in rooting powder and plants them in a nursery bed. After a few weeks the stems grow roots and become new bushes.
   Explain why the new bushes grown from the cuttings have the same characteristics as the original bush.2 marks
2. In 1996 scientists in Scotland produced Dolly the sheep. They removed the nucleus from an unfertilised egg cell taken from Sheep 1 and replaced it with the nucleus from an udder cell taken from Sheep 2. A small electric pulse made the cell start to divide, and the resulting embryo was placed in the uterus of Sheep 3, who gave birth to Dolly.
   Dolly looked like Sheep 2, not like Sheep 3, who gave birth to her. Explain why.2 marks
3. A biotechnology company grows orchids by tissue culture. Small pieces of tissue from one orchid are placed on sterile jelly containing nutrients and rooting hormone. In a trial, the company used 10 pieces of tissue at each of four hormone concentrations (0, 1, 2 and 3 mg per litre), kept all of them at 22 °C in the light for six weeks, and counted the roots on each plantlet. The mean number of roots per plantlet was 1.2, 3.8, 6.1 and 6.3 respectively.
   Identify the independent variable, the dependent variable and one control variable in this trial.3 marks