Diatomaceous earth consists of the fossilized remains of diatoms, which are unicellular algae with silica-based cell walls. Because of its hardness and fine, porous structure, it is widely used as a mild abrasive in polishes for metals and automotive finishes, as well as in filtration systems.
1312
Which substance derived from algae is utilized in the processing and manufacturing of natural and synthetic rubbers?
Algin, or alginic acid, is a polysaccharide extracted from brown algae. It is widely used in various industries, including the rubber industry, as a stabilizer, thickener, and emulsifying agent in latex processing.
1313
Diatomaceous earth is primarily composed of the fossilized remains of which organisms?
Diatomaceous earth, also known as diatomite, is a naturally occurring, soft, siliceous sedimentary rock. It is formed by the accumulation of the silicified cell walls (frustules) of dead diatoms, which are a major group of algae, over geological time periods.
1314
Which physical method of sterilization is primarily responsible for the coagulation of microbial proteins?
Moist heat, such as autoclaving, is highly effective at sterilization because the presence of water facilitates the denaturation and coagulation of proteins at lower temperatures compared to dry heat. The water molecules help break hydrogen bonds within the protein structure, leading to rapid cell death in microorganisms.
1315
Which group of organisms is commonly utilized to assist in the filtration and purification of water in aquariums and ponds?
Certain algae are used in biological filtration systems for aquariums and ponds because they absorb excess nutrients like nitrates and phosphates, thereby helping to maintain water quality and clarity.
1316
Which algal genus is frequently utilized in the production of food items such as cakes and pastries?
Chlorella is a unicellular green alga rich in proteins, vitamins, and minerals. It is often used as a nutritional supplement or food additive in various baked goods, including cakes and pastries, to enhance their nutritional profile and color.
1317
Which marine organism serves as a historical source for ammonia and charcoal?
Historically, large brown algae like kelp were harvested and processed to extract various chemicals. The burning of dried kelp was a traditional method for obtaining potash and other mineral-rich residues, including charcoal and ammonia-related compounds used in early industrial applications.
1318
What is a primary commercial application for the red alga Gelidium?
Gelidium is a genus of red algae primarily harvested for the production of agar. While agar is most famous for its use as a solidifying agent in microbiological culture media, it is also utilized in the pharmaceutical industry as a bulk laxative because it absorbs water and expands in the digestive tract.
1319
Which of the following is considered a rich source of essential minerals like zinc, iron, copper, boron, and manganese?
Kelp is highly regarded for its dense nutritional profile. It absorbs a wide array of trace elements from seawater, making it an excellent natural source of essential minerals such as zinc, iron, copper, boron, and manganese for human consumption.
1320
Which group of organisms is responsible for the production of antibiotics like streptomycin and terramycin?
Streptomycin and related antibiotics are typically produced by Actinobacteria (often grouped with cyanobacteria in older or simplified texts). These soil-dwelling filamentous bacteria are the primary source of many clinically significant antibiotics. Note: The source answer lists cyanobacteria, which may be a taxonomic simplification in the provided curriculum.
