Molecular Genetic Techniques

Question 1

What is the purpose of making more copies of DNA?

Answer 1

• To enable studies of genetic variation
• For in use in human health and disease
• Agricultural Purposes (adding genes to animals giving the productive advantage)

Question 2

What are the models of human disease and why is this model chosen?

Answer 2

• Mice are commonly used as experimental model systems for human diseases
• They are used because they display symptoms similar to those observed in human and allow the study of disease development and treatments

Question 3

What are GMO’s and what is their purpose?

Answer 3

GMOs are genetically modified organisms. Specific genes that hold a production value are added to the plants such as tomatoes being modified to slow the ripening process and delay rotting

Question 4

What are clones and what are the two methods in making them?

Answer 4

Clones are genetically identical molecules, cells or organisms all derived from a single ancestor.

The two cloning methods are Embryo Splitting and Nuclear Transfer

Question 5

What is involved in cloning by Embryo splitting?

Answer 5

• Unfertilised eggs are collected from mother
• Fertilised in vitro
• Split after embryo starts developing
• Form two genetically identical embryos

Question 6

What is involved in cloning via nuclear transfer (Cell Fusion)?

Answer 6

• The nucleus is removed from the egg in order to eliminate the genetic contribution from the egg donor
• The nuclear information for a somatic cell of the individual to be cloned is fused in egg (providing genetic information)

Question 7

What is involved in cloning through nuclear transfer (Nuclear injection)?

Answer 7

• Somatic nucleus is injected into an enucleated egg

- Is more efficient/ higher success rate than nuclear transfer by cell fusion

Question 8

What is Recombinant DNA?

Answer 8

The joining together of DNA molecules from 2 different species that are inserted into a host organism to produce new genetic combination that are of value to science, medicine agriculture & industry

Question 9

What does Recombinant DNA allow for?

Answer 9

• Locating, mapping, isolating, sequence and transfer of genes
• Produce human proteins in animals
• Make disease-resistant food crops

Question 10

What are the techniques used in Recombinant DNA?

Answer 10

1. Cut the DNA into reproducible fragment via restriction enzyme
2. Paste DNA fragments into carrier molecule for transfer to host cells via vectors
3. Grow host cells to obtain large quantities of cloned DNA for study

Question 11

What are Southern, Northern and Western Blotting?

Answer 11

• Southern Blotting is a method of transferring DNA fragments from a gel to a membrane filter
• Northern Blotting is used to detect a specific RNA within a mixture of many RNA molecules.
• Western Blotting used to detect a specific protein among a mixture of proteins.

Question 12

What is Restriction Mapping and why is it useful?

Answer 12

• A restriction map establishes the number and order of restriction sites and the distance between restriction sites on a cloned DNA segment
• It provides information about length of the cloned insert and the location of restriction sites within the clone

Question 13

What is Fluorescence in situ hybridisation (FISH)?

Answer 13

• Molecular cytogenetic technique
  Detect chromosomal aberrations
• Used to map the locations of genes or other DNA sequences within large DNA sequences within large eukaryotic chromosomes
• Fluorescently labelled DNA probes

Question 14

What are stem cells and what are the two types?

Answer 14

Stem cells are unspecialised cell and have the ability to differentiate into other cell types

• Embryonic Stem Cells (Pluripotent)
• Adult Stem Cells (can only differentiate into certain cell types)