Cloning in animals

Question 1

Natural cloning in animals:

Answer 1

When animals produce G.I offspring using asexual reproduction

Question 2

Describe natural cloning in invertebrates:

Answer 2

Regeneration/fragmentation
–>forms new G.I offspring from broken body parts

Question 3

Describe natural cloning in vertebrates:

Answer 3

Occur naturally when early embryo splits into two G.I embryos

Each embryo grows independently = monozygotic twins

Question 4

What is artificial embryo twinning?

Answer 4

Process whci single embryo manufacturally split –> separating cells b4 differentiation.
–> produces multiple identical offspring from single embryo.

Used to maximise good dairy produce from cattle

Question 5

Describe process of A.T?

Answer 5

• Female treated with hormones -> produce multiple ova
• Ova extracted + fertilised in Petri dish to produce embryo
• Embryo divides into several cells –> embryo split while cells = totipotent
• Each cell placed into own Petri dish –> develop into individual embryos
• Embryos implanted into uterus of surrogate mother for development.

Question 6

What is somatic cell nuclear transfer?

Answer 6

Nucleus transferred from somatic cell of 1 animal into ovum of another animal to form embryo.

–> Leads to development of clone of organism which nucleus extracted from

Question 7

Describe the steps in SCNT:

Answer 7

1. Somatic cell nucleus removed from adult animal
2. Ovum of different female animal of same species enucleated
3. Nucleus from somatic cell transferred into enucleated ovum
4. Somatic nucleus fused with enclueated ovum –> stimlulated by electric shock (electrofusion)
5. Fused cell begins dividing –> embryo
6. Embryo implanted into uterus of surrgoate mother
7. Surrogate gives birth to clone of somatic cell donor

Question 8

What are the applications of animal cloning?

Answer 8

Medical research: drug testing/disease modelling

Conservation: offers method to boost number of endangered species from limited gene pool

Agriculture: Cloning replicate animals woth desirable characteristics for selective breeding to improve product quality

Pharming: G.E animal clones = used to produce therapeutic proteins

Stem cells: Cloned embryos provide source of immunocompatible stems cells for tissue repair

Question 9

Arguments for animal cloning:

Answer 9

• Ensures transmission of desirable genetic traits to multiple offspring
• Enables reproduction of infertile animals
• Helps preserve biodiveroisty
• Rapidly increase population size of certain species
• Facilitates medical advancements –> alleviate suffering

Question 10

Arguments against animal cloning:

Answer 10

• High costs + technically complex
• Reduced genetic diveristy = increases disease risk
• Potential for shorter lifespans in clones
• Ethical concerns - destruction of embryos
• Cloned animals = health issues
• SCNT = inefficient –> many ova = 1 single cloned offspring –> high failure rates