Cloning - (1)

What is a clone?

A genetically identical organism or section of DNA.

What are reproductive cloning technologies?

Artificially induced interventions producing genetically identical clones.

Name the six cloning technologies.

SCNT, therapeutic cloning, embryo splitting, tissue culture, cutting, grafting.

What does SCNT stand for?

Somatic cell nuclear transfer.

What is SCNT?

Transfer of a somatic cell nucleus into an enucleated egg cell.

What is enucleation in SCNT?

Removal or destruction of the nucleus from the donated egg cell.

What happens during SCNT extraction?

The nucleus is extracted from the donated somatic cell.

What happens during SCNT insertion?

The somatic cell nucleus is inserted into the enucleated egg.

What happens during SCNT development?

The cell divides into an embryo, which is implanted into a surrogate.

Which donor is the SCNT clone genetically identical to?

The somatic cell donor.

Why is the SCNT clone mainly identical to the somatic donor?

The transferred nucleus contains most of the genetic material.

What does the egg cell provide during SCNT?

Mitochondrial DNA and cytoplasm.

Who was Dolly?

The first mammal cloned using SCNT, in 1997.

What cell supplied Dolly's transferred nucleus?

An adult sheep's mammary gland cell.

What did Dolly demonstrate?

A complete organism can develop from DNA in one diploid cell.

What is one major complication of animal SCNT?

Severe developmental abnormalities and shorter life expectancy.

Why is human reproductive cloning controversial?

It involves ethical concerns and destruction of eggs and embryos.

What is one proposed reason clones may age prematurely?

Shortened telomeres may contribute to faster ageing.

What happened to Dolly at six years old?

She was euthanised after developing a severe lung infection.

Why is reproductive cloning considered controversial?

Live-birth success is low and many offspring suffer deformities.

What is therapeutic cloning?

Cloning particular tissue for medical benefit.

What could therapeutic cloning potentially replace?

Treatments such as organ transplants and skin grafts.

Why might cloned tissues avoid rejection?

They are genetic clones of the patient.

What is another advantage of therapeutic cloning?

Tissues or organs may be produced faster than transplant waitlists.

What cells can be harvested from a developing embryo?

Pluripotent embryonic stem cells.

What is embryo splitting?

Division of an early embryo into several individual embryos.

What is another name for embryo splitting?

Artificial twinning.

Why are embryos split in agriculture?

To produce multiple genetically identical offspring with desirable traits.

What happens to split embryos?

They are implanted into surrogate mothers to complete development.

When can embryo splitting occur?

When embryonic cells are totipotent.

How can IVF be used with embryo splitting?

Desirable eggs and sperm are selected, fertilised, then embryos are split.

Give an agricultural example of selective cloning.

Cows and bulls with desirable traits can produce split embryos.

What traits might farmers select for?

High milk production or increased muscle mass.

Name three complications linked to embryo splitting.

Preterm birth, low birth weight, and foetal conditions such as TTTS.

What maternal complications can occur with embryo splitting?

Hypertensive disorders and gestational diabetes.

Are complications more frequent with assisted reproductive technologies?

Yes, compared with natural conceptions.

What is plant cloning?

Creating an organism with an identical genotype to its parent.

Name three plant cloning technologies.

Tissue culturing, plant cutting, and plant grafting.

What happens in laboratory plant cloning?

A plant sample grows on a medium, producing roots, shoots and a plantlet.

What is plant tissue culturing?

Cloning plant cells on nutrient culture medium in a controlled environment.

What is another name for plant tissue culturing?

Micro-propagation.

What is a callus?

A mass of plant cells.

What is a disadvantage of plant tissue culturing?

It can be expensive and specialised.

How can tissue culture help conservation?

Rare and endangered plants can be cloned to help prevent extinction.

Which Australian plant was saved through cloning?

The Wollemi pine (Wollemia nobilis).

How does plant cloning benefit horticulture?

Plants can be rapidly produced year-round in less space.

Why can desirable plant characteristics be maintained through cloning?

Offspring have the same genotype as the parent.

What is plant cutting?

Growing a plant using a fragment of the original leaf, stem or root.

How is a plant cutting prepared?

A shoot is cut at an angle and placed into root powder.

Why is root powder used in plant cutting?

To help the cutting form new roots.

What is a major advantage of plant cutting?

It is a cheap and simple cloning method.

What is plant grafting?

Attaching a scion to a plant with an established rootstock.

What is a scion?

The stem of one plant attached during grafting.

What is a rootstock?

The plant with the already developed root system.

What happens after grafting?

The two plant sections grow and fuse together.

Which plant is genetically cloned by grafting?

The plant from which the scion was taken.

What are two advantages of grafting?

It can provide disease resistance and cold tolerance.

How can grafting increase productivity?

It can combine useful characteristics with rapid plant growth.

Name six advantages of plant cloning.

Mass production, year-round cultivation, disease resistance, faster maturation, conservation, cost-effectiveness.

What is a major biological disadvantage of plant cloning?

Reduced genetic diversity.

Name other disadvantages of plant cloning.

Genetic abnormalities, high costs, sterile environments, acclimatisation issues, limited species suitability.

Why is a sterile environment needed for tissue culture?

To reduce contamination during the specialised cloning process.

What is an acclimatisation challenge?

Cloned plants may have difficulty adjusting to new growing conditions.

Why can low genetic diversity be dangerous?

Cloned populations are more vulnerable to disease, pests and environmental change.

How can cloning affect a species' genetic diversity?

Unrestrained cloning can reduce genetic diversity within the population.

Why is genetic diversity biologically important?

It helps populations respond to disease, pests and environmental change.

What is one key disadvantage of reproductive cloning in animals?

Many cloned offspring can suffer developmental abnormalities.

Why is human reproductive cloning opposed by many scientists?

They have ethical concerns about experimenting on humans.

What is the key difference between sexual and asexual reproduction?

Sexual reproduction increases genetic diversity; asexual reproduction produces clones.

What is the main biological advantage of sexual reproduction?

It produces genetically diverse offspring.

What is the main biological disadvantage of cloning?

It produces little genetic diversity.