Cloning

Cloning

Asexual Reproduction

Multiple Choice

Cloning is a form of asexual reproduction

• True

• False

Vocabulary

• Somatic cell - any body cell except the sex cells

• Embryo - Fertilised egg

• Surrogate mother - carries a child in the uterus but is not the biological mother

Cloning

• Cloning is the production of a new individual that contains the same genetic information as the parent

• A form of asexual reproduction

• Occurs naturally and artificially

• Artificial methods of cloning are: cuttings & grafts, tissue culture, embryo splitting and nuclear transfer

Multiple Choice

Cloning can only be done artificially

• True

• False

Cutting & grafts

• Both forms of asexual reproduction in plants

• Growing plants from cuttings is one of the oldest and simplest forms of cloning

• To clone a plant in this way, a section of plant (root, leaf or stem) is removed from the parent plant and put into water

• The cells in the cut area will undergo mitosis and differentiate into different structures

• Grafting is more complex and involves transferring part of the stem of a plant on to the cut stem of another plant

• Advantages of grafting: increase yield, increase tolerance to cold, disease resistant, early fruiting and rapid growth

Multiple Choice

An advantage of grafting is:

• Increase crop yield

• Decreases resistance to frosts

• Decreases resistance to diseases

Tissue Culture

• Fragments or single cells from a parent plant are selected and grown in a culture medium (contains nutrients and hormones)

• Plant fragments are treated with a sterilising solution to kill any bacteria or fungi

• Technique used to grow a large number of plants quickly

• Is expensive and labor intensive

Multiple Choice

An Advantage of tissue culture is:

• Is expensive

• Allows farmers to grow a large number of crops quickly

• Takes a lot of time and labor

Embryo Splitting

• An egg is fertilised in a petri dish (IVF) and scientists are able to split the embryo (up to 16 cell stage) to create multiple, genetically identical embryos

• Embryos are then implanted into surrogate mothers

• Used in livestock breeding programs to increase numbers of offspring born

Nuclear Transfer

• The nucleus is removed from an unfertilised egg and replaced with the nucleus of an adult somatic cell

• The egg is transplanted into into a surrogate mother where it will develop into an identical copy of the donar somatic cell

• This is how Dolly the sheep was cloned

Multiple Choice

Nuclear transfer is when:

• a nucleus is removed from an unfertilised egg and replaced with the nucleus of an adult somatic cell and implanted to a surrogate

• an egg is fertilised in a petri dish and then split multiple times to before it divides over 16 cells to create multiple clones

Dolly the sheep

- 1996

- First mammal to be cloned

- Was euthanised at 6 years old (sheep lifespan is 12 years) due to an incurable lung disease and arthritis

To Do:

• Finish writing any notes necessary from the power point