Cloning and Biotechnology

Question 1

What are the key stages of somatic cell nuclear transfer (SCNT)?

Answer 1

1. A somatic cell nucleus is removed from an adult animal
2. An ovum of a different female animal of the same species is enucleated
3. The nucleus from the somatic cell is transferred into the enucleated ovum
4. The somatic nucleus is fused with the enucleated ovum, often stimulated by electrofusion
5. The fused cell begins dividing, forming an embryo
6. This embryo is implanted into the uterus of a surrogate mother
7. The surrogate eventually gives birth to a clone of the somatic cell donor

Question 2

What are the key stages of artificial twinning?

Answer 2

1. A female organism is treated with hormones to produce multiple ova
2. The ova are extracted and fertilised in a Petri dish by semen to produce an embryo
3. The embryo divides into several cells and while the cells are still totipotent, the embryo is split
4. Each cell is placed into its own Petri dish to develop into individual embryos
5. The embryos are implanted into the uteruses of surrogate mothers for development

Question 3

What are the key stages of inoculating agar?

Answer 3

1. Sterilise all equipment before use eg bunsen burner
2. Dip sterilised inoculating loop into a starter culture
3. Transfer the microbes to a Petri dish containing a sterile nutrient medium
4. Close the plates and lightly tape them so they are not completely sealed
5. Label the plates and incubate upside down under the required conditions
6. Repeat steps one to five for a control agar dish with no bacteria
7. Assess microbial growth by observing colony formation on the agar