Biotechnology Quiz

What is the role of anaerobic respiration in yeast during the production of ethanol for biofuels?

• Anaerobic respiration in yeast produces carbon dioxide, which is harmful for biofuel production.
• Yeast only uses aerobic respiration for ethanol production in biofuels.
• Anaerobic respiration in yeast generates heat, which is used to power engines.
• Anaerobic respiration in yeast produces ethanol through fermentation, which is essential for biofuel production.

Answer explanation

Anaerobic respiration in yeast converts sugars into ethanol and carbon dioxide without oxygen. This process is crucial for biofuel production, as it allows for the efficient fermentation of biomass into renewable energy sources like ethanol.

What is the role of yeast during bread-making?

• Yeast adds flavor to the bread without affecting its texture.
• Yeast is used to color the bread crust during baking.
• Yeast acts as a preservative to extend the shelf life of bread.
• Yeast helps the dough rise by producing carbon dioxide during fermentation.

Answer explanation

Anaerobic respiration in yeast during bread-making produces carbon dioxide and ethanol. The carbon dioxide causes the dough to rise, creating a light texture, while the ethanol contributes to flavor. This process is essential for leavening bread.

What is the use of pectinase in fruit juice production?

• Pectinase is used to add flavor to fruit juice.
• Pectinase is used to preserve the color of fruit juice.
• Pectinase is used to carbonate fruit juice.
• Pectinase is used to clarify fruit juice and improve yield by breaking down pectin.

Answer explanation

Pectinase is an enzyme used in fruit juice production to break down pectin, a polysaccharide in cell walls. This process clarifies the juice, increases yield, and improves extraction efficiency, resulting in a clearer and more palatable product.

What is the advantage of biological washing powders that contain enzymes?

• They clean effectively at lower temperatures and are energy-efficient.
• They require higher temperatures for effective cleaning.
• They contain more fragrances for a pleasant smell.
• They are cheaper than regular detergents.

Answer explanation

Biological washing powders use enzymes to break down stains and dirt at lower temperatures, making them effective and energy-efficient. They target proteins, fats, and carbohydrates, enhancing cleaning power while being environmentally friendly.

What is the use of lactase to produce lactose-free milk?

• Lactase is a type of milk that contains lactose.
• Lactase is used to thicken milk for better texture.
• Lactase is used to add flavor to milk.
• Lactase is used to break down lactose into simpler sugars, making lactose-free milk.

Answer explanation

Lactase is an enzyme that breaks down lactose into glucose and galactose. By adding lactase to regular milk, lactose is converted, resulting in lactose-free milk suitable for lactose-intolerant individuals.

Describe how fermenters can be used for the large-scale production of useful products by bacteria and fungi.

• Fermenters are primarily used for growing plants and not microorganisms.
• Bacteria and fungi cannot produce insulin or penicillin in fermenters.
• Fermenters enable large-scale production of insulin, penicillin, and mycoprotein by providing controlled environments for bacteria and fungi to grow and produce these valuable products.
• Fermenters are used only for small-scale production of beverages.

Answer explanation

Fermenters enable controlled growth of bacteria and fungi for large-scale production. They optimize conditions for producing insulin, penicillin, and mycoprotein, ensuring high yields and efficiency in bioprocessing.

What are the conditions that need to be controlled in a fermenter?

• Light intensity, wind speed and humidity

• Carbon dioxide concentration, nitrogen content and light exposure

• Fermenter size, materials and color.

• Temperature, pH, and oxygen levels.

Answer explanation

In a fermenter, key conditions to control include temperature, pH, oxygen levels, and nutrient supply. These factors ensure optimal microbial activity and product yield, preventing contamination and promoting efficient fermentation.

Which one is the example of how genetic modification is useful in agriculture to produce higher quality crops?

• Organic corn that is fertilised by organic materials only.

• Bt cotton, which is genetically modified to resist bollworm pests.
• Different wheat varieties with no pest resistance.

• Naturally herbicide-resistant soybeans.

Answer explanation

Examples of genetic modification include the creation of Bt corn, which is engineered to resist pests, and golden rice, enriched with vitamin A to combat malnutrition. These modifications enhance crop yield and nutritional value.

The process of genetic modification using bacterial production of a human protein involves isolating the gene and inserting it into the ... .

• chromosome
• virus
• ribosome
• plasmid

Answer explanation

The process involves isolating the gene for the human protein, inserting it into a plasmid, transforming bacteria with the plasmid, and then culturing the bacteria to produce the protein, which can be harvested and purified.

Which statement shows one of the disadvantages of genetically modifying crops?

• Genetically modified crops can lead to reduced biodiversity.
• Genetically modified crops require less water than traditional crops.
• Genetically modified crops are always more nutritious.
• Genetically modified crops can increase crop yields.

Answer explanation

Genetically modifying crops can increase yield, enhance resistance to pests, and reduce the need for chemical pesticides. However, it may lead to biodiversity loss, potential health risks, and ethical concerns regarding food safety.