Chapter 17: Microbes and Biotechnology Command Term to Master

Worksheet 17.2

Chapter 17: Microbes and biotechnology – command term to master

Outline Give a brief account or summary.

Examples

Assessment statement F.1.4 Outline the diversity of habitat in the Archaeabacteria as exemplified by methanogens, thermophiles, and halophiles.

Assessment statement F.2.4 Outline the conditions that favour denitrification and nitrification.

Assessment statement F.2.6 Outline the role of saprotrophic bacteria in the treatment of sewage.

Assessment statement F.4.2 Outline the production of soy sauce (using Aspergillus oryzae).

Author’s comment

Questions using the command term outline are found in Paper 3. You are expected to know a series of facts in order to answer the question fully. Answers can be in the form of bulleted points. Full sentences are not required for complete marks to be given.

Example answer

Outline the diversity of habitat in the Archaea.

Note: You are expected to know the names of the three types of Archaea.

Methanogens

· Strict anaerobes

· Use carbon dioxide to make methane

· Live in the guts of termites or cattle

Thermophiles

· Heat lovers

· Live in sulfur hot springs which are very acidic

· Can live in hydrothermal vents under the ocean

Halophiles

· Salt lovers

· Live in the Great Salt Lake where salinity is 10 times the salt content of the ocean.

Example answer

Outline the conditions that favour denitrification and nitrification.

Nitrification by Nitrobacter and Nitrosomonas

· Available oxygen

· Neutral pH

· Warm temperatures

Denitrification by Pseudomonas

· No available oxygen

· High nitrogen input.

Example answer

Outline the role of saprotrophic bacteria in the treatment of sewage.

Note: You are expected to know which two systems are being asked for here.

Trickling filter beds

· A bed of stones is used with saprophytic bacteria adhering to the stones

· Sewage trickled over these stones is broken down by the bacteria

· Clean water which trickles out is further treated with chlorine to kill the bacteria

Reed bed system

· This is an artificial wetland used to treat waste water

· Reeds are growing in the wetlands and use some waste for nutrient

· Saprophytic bacteria are present which also breakdown waste

· Reeds use the nitrates and phosphates which are products of the breakdown as nutrients.

Example answer

Outline the production of soy sauce.

Note: You are expected to know that Aspergillus oryzae is the bacterium responsible for the fermentation process.

· Aspergillus oryzae is mixed with the soybean culture

· The soybean culture is a combination of salt, soybeans and water

· Carbohydrates are broken down into glucose by fermentation

· Proteins are broken down into peptides and amino acids

· Fermentation takes 6–8 months.