Cloning and biotechnology part 2

Question 1

give examples of natural cloning

Answer 1

• yeast reproduce by budding and bacteria reproduce by binary fission and those that give asexual reproduction

Question 2

what are the plants that can produce natural clones by vegetative propagation

Answer 2

• rhizomes
• stolens
• suckers
• tubers
• bulbs

Question 3

describe rhizomes

Answer 3

• they grow horziontally underground away from the parent plant
• have nodes from which roots can develop
  eg - bamboo

Question 4

describe Runners (Stolens) n

Answer 4

the grow horizontally away from the parent plant on the surface of the soil
- new shoots and roots can develop frm the nodes or form at the end of the stolon
eg - strawberries

Question 5

describe suckers

Answer 5

shoots that grow from the sucker buds present on the shallow roots of a parent plant, close to the base of an older stem
- elm trees

Question 6

what are the natural methods of cloning plants

Answer 6

• vegetative propagation
• cuttings
• grafting - joining the shoot of one plant to the grwoing stem and teh root of another plant
• layering

Question 7

describe artificial cloning in plants

Answer 7

tissue culture

Question 8

describe different types of cuttings that can be used

Answer 8

• root cuttings in which a section of root is buried just below the soil surface and produce new shoots
• scion cuttings which are dormant woody twigs
• lead cuttings in which a leaf is placed on moist soil, the leaves develop new stems and new roots, some leaves may produce many new plants from one cutting

Question 9

describe negatives of cloning

Answer 9

• large scale cloning by taking cuttings can be time consuming and needs a lot of space

Question 10

what is micropropagation

Answer 10

• this si when tissue culture is used to produce lots of cloned plants quickly

Question 11

What are the methods of artificial cloning (reproductive clonning)

Answer 11

• artificial embryo twinning

- somatic cell nuclear transfer

Question 12

what is embryo twinning used for

Answer 12

• technique used to clone elite farm animals or animals for scientific research but the precise genotype and phenotype of the offspring produced will depended upon the sperm and egg used therefore the precise phenotype will be unknown until the animals are born

Question 13

what are the methods of non reproductive cloning

Answer 13

• thrapeutic cloning

Question 14

describe Somatic cell nuclear transfer

Answer 14

1. a somatic cell (any cell that is not a reproductive cell) is taken from an organism
2. an oocyte (immature egg) is take from anothe organism and its nucleus is removed to form an enucleated oocyte
3. the nucleus from the original organism is inserted into the enucleated oocyte, therefore the oocyte now contains the genetic information from the original organism
4. the nucleus and enuclated oocyte are fused together and stimulated to divide producing an embryo, divides by mitosis
5. the embryo is then impatned into a surrogate mother and the offspring is born

Question 15

what are the uses of animal cloning

Answer 15

• test new drugs, variables coming from genetic differences are removed
• save endangerd species
• increase number of animals with desirable characteristics to breed from
• genetically modified to produce a useful characterstics
• cloning doesnt have to be used to make whole animals, can be used to make embryonic stem cells and these can replace damaged cells an treat a wide range of diseases
• wont be rejected from patients own immune system

Question 16

arguments against animal cloning

Answer 16

• time consuming, difficult and expensive
• no genetic variability, so undesirable genetic characteristics are always passed on to clones, this means that all of the cloned animals in a population are susceptible to the same disease
• some evidence suggests that clones may no live as long as natural offspring this is unethical
• using cloned human embryos as a source of stem cells is controversial - embryos are destroyed after embryonic stem cells have been harvested