Biotechnology and genetic modification Flashcards iGCSE Biology

[q] Why Sterilisation is required in fermentation?

[a] Sterilisation is required to Prevent Contamination.

[q] How Sterilisation is done in fermentation?

[a] Sterilisation is done by Steam/Autoclave/Ultraviolet Radiation/Bleach.

[q] Why Nutrients are used in fermentation?

[a] Nutrients are used by microorganisms for growth and reproduction.

[q] How Nutrients are used in fermenters?

[a] Nutrients are used through Nutrient Inlet.

• Supplies nutrients for energy and growth.

[q] Why the Optimum pH is maintained in the fermenter?

[a] Optimum pH is maintained because Enzymes are efficient and do not denature in the fermenter.

[q] How the Optimum pH is maintained in the fermenter?

[a] Optimum pH is maintained through Probe/Sensor/Data logger.

• Monitors temperature and pH

[q] Why the Optimum Temperature is maintained in fermenter?

[a] Optimum Temperature is maintained so that Enzymes are efficient and do not denature.

[q] How the Optimum Temperature is maintained in fermenter?

[a] Optimum Temperature is maintained through Water Jacket in the fermenter.

[q] What does the Optimum Temperature does in the fermenter?

[a] It Maintain and control temperature in the fermenter.

[q] Why Oxygen is required in the fermenter?

[a] Oxygen is supplied for Respiration in the fermenter.

[q] How the Oxygen is supplied in fermenter?

[a] Oxygen is supplied through the Air Supply in the fermenter.

Air is pumped in the fermenter.

[q] Why the Stirring is performed in the fermenter?

[a] Stirring is performed to

• Enables microorganism to always have access to nutrients;
  
• Keeps microorganism suspended in mixture;
  
• To create uniform, homogenous mixture;
  
• To form pellets of fungus;

[q] How the Stirring is performed in the fermenter?

[a] Stirring is performed through the Stirrer/Paddle.

[q] Why the Outlet is present in the fermenter?

[a] Outlet allows collection of the liquid containing penicillin after fermentation.

[q] How the Outlet perform in the fermenter?

[a] Through the Filter the outlet performs. Penicillin is filtered through the outlet in the fermenter.

[q] Principles of enzyme production from micro-organisms

[a]

[q] Why the fermenter is used in fermentation process?

[a]

• For even / uniform, distribution / concentration, of contents / AW;
  
• Ensure more access of bacteria with, medium / AW;
  
• Prevent settling / clumping of, contents / AW;
  
• So oxygen / glucose / nutrients, dissolves;
  
• So that growth is not limited;
  
• So bacteria can absorb substances (more easily);
  
• Bacteria need oxygen for respiration;

[q] What are the Advantages of Biofuel against Fossil Fuel?

[a]

• Biofuels are renewable;
  
• Plants uses carbon dioxide from the atmosphere;
  
• Ref to photosynthesis;
  
• Less likely to cause acid rain and global warming / climate change / (enhanced) greenhouse effect;
  
• Uses waste from crops for energy;

[q] What are the Functions of DNA?

[a] The Functions of DNA are:

• Store of genetic information;
  
• DNA / genes, codes for proteins;
  
• Sequence of bases in DNA codes for sequence of amino acids;
  
• Transfer of information to daughter cells (during mitosis);
  
• DNA copied as mRNA;

[q] Genetic Engineering

[a]

• Restriction enzyme cuts human DNA;
  
• Plasmid is cut with the same restriction enzyme (as DNA);
  
• Sticky ends are formed that are complementary to sticky ends of gene;
  
  
  • Base sequences are complementary;
    
• DNA ligase used to join plasmid and gene together;
  
• Formation of recombinant DNA / plasmid;

[q] Samples were taken from the fermenter at frequent intervals and the number of live bacteria was determined. The results are shown in Fig. 1.2.

Describe and explain what happens to the number of live bacteria shown in the stages labelled A, B, C and D in Fig. 1.2. [6 Marks]
(0610/43 May/June 2019)

[a]

[q] State two beneficial examples of genetic engineering

[a] The beneficial examples of genetic engineering are

• Drought / salt/ pollution/metal / frost/ stress / cold resistant;
  
  
  • Increased, yield /productivity;
    
  • Extend range where crops can be grown;
    
• Herbicide/Pesticide resistance;
  
  
  • Increased yield/productivity;
    
• Crop plants produce own insecticides;
  
  
  • Less insecticide used;
    
  • Increased yield;
    
• Vitamin / nutrient, enrichment / β carotene (golden rice);
  
  
  • Increased nutritional value;
    
• Pathogen resistant /bt;
  
  
  • Increased productivity / less pesticide use;
    
• Antigens / vaccines / pharmaceuticals;
  
  
  • E.g. Insulin cheap production of medicines;
    
• Flavour/ texture /ripening;
  
  
  • Improved customer satisfaction / shelf life;

[q] State two uses of Yeast in industry

[a] Yeast is used in

• Bread-making;
  
• Alcohol production;
  
• Producing biofuels/ethanol;
  
• Production of yeast extract;
  
• GM yeast;

[q] What are the advantages of genetically modifying crops?

[a] The advantages of Genetically modified crops are Higher yield, Shorter growing seasons, Better nutrients and vitamins, Uniform shape (e.g: round apple).

[q] What are the disadvantages of genetically modifying crops?

[a] The disadvantages of genetically modifying crops are:

• Loss of biodiversity
  
• Potential development of weeds resistant to herbicides
  
• Long term health effects unknown
  
• Farmers tied to large agricultural suppliers, potentially manipulating seed prices.

[q] Why are bacteria useful in biotechnology and genetic engineering?

[a] Bacteria are useful in biotechnology and genetic engineering because of

1. Rapid reproduction rate
2. Ability to make complex molecules (e.g: proteins)
3. No ethical concern over manipulation and growth
4. Genetic code shared with all other organisms
   • Genes from animals/plants can be successfully transfered into bacterial DNA
5. Presence of plasmids
   • Small circular pieces of bacterial DNA

[q] Why is pectinase used in fruit juice production?

[a] Pectinase is used in fruit juice production for:

• Clearer juice
  
  
  • Pectin digested to soluble products.
    
• Sweeter
  
  
  • Pectin broken down into sugars.
    
• Extracts More juice
  
  
  • Pectin broken down, easier to extract juice.