Week 14 - biotechnology

Question 1

Vector

Answer 1

• nucleic acid molecules that deliver a gene into a cell

USEFUL PROPERTIES

• small enough to manipulate in a lab
• survive inside cells
• contain recognisable genetic marker
• ensure genetic expression of gene
• inc. VIRAL GENOME & PLASMIDS

Question 2

Enzymes in DNA sequencing

Answer 2

• Restriction enzyme: cleaves DNA

- DNA ligase: seals DNA into an opening created by the restriction enzyme

Question 3

Restriction enzmes

Answer 3

• cleave (cut) DNA at specific sites
• enzymes are used by bacteria against viruses, the enzymes restrict bacterial viruses from being able to invade some bacteria

Question 4

Plasmids

Answer 4

• small circular chromosomes
• contain genes not essential for survival
• have their own origin of replication → can replicate independently of the main chromosome

Question 5

linking gene and vector

Answer 5

• DNA LIGASE joins the two fragments forming a stable DNA molecule
• catalyses formation of a PHOSPHODIESTER BOND betw. adjacent phosphate & hydroxyl groups of DNA nucleotides
• same enzyme joins Okazaki fragments on lagging strand in replication

Question 6

Applications of polymerase chain reaction

Answer 6

• allows the investigation of minute samples of DNA
• forensics: drop of blood, cells at base of hair
• detection of genetic defects in embryos by analysing single cell
• analysis of mitochondrial DNA from early human species

Question 7

agricultural application

Answer 7

• adoption of GM crops has being resisted in some areas bc of:
  → crop safety for human consumption
  → movement of genes into wild relatives

Question 8

Herbicide resistance

Answer 8

GLYPHOSATE (ROUND UP) kills all plants

• gene from salmonella conveys resistance to glyphosate
• farmers kill weeds w/o killing crops
• reduces tilling and soil erosion