Question 1: Define Archaea and explain how they differ from bacteria and eukaryotes.

Answer: Archaea are a group of single-celled microorganisms that are distinct from bacteria and eukaryotes, characterized by unique genetic and biochemical features, such as different membrane lipids and RNA sequences.

Question 2: Describe one environment where Archaea are commonly found and explain why they thrive there.

Answer: Archaea are commonly found in extreme environments like hot springs or deep-sea vents, where they thrive because they can survive high temperatures, acidity, or high salinity that inhibit other organisms.

Question 1: What is the primary genetic difference between Archaea and bacteria?

Answer: Archaea have different sequences of their ribosomal RNA genes compared to bacteria, reflecting a more distant evolutionary relationship.

Question 2: Explain how the cell membrane of Archaea differs from that of bacteria.

Answer: Archaeal cell membranes contain ether bonds and unique lipids that make them more stable in extreme environments, unlike bacterial membranes which have ester bonds.

Question 1: If a hot spring has a temperature of 80°C and an Archaea species can survive up to 100°C, what is the maximum temperature margin in which these Archaea can live?

Answer: 20°C (100°C - 80°C)

Question 2: A sample of water from a deep-sea vent contains 2.5 x 10^6 Archaea per milliliter. How many Archaea are present in a 500 mL sample?

Answer: 1.25 x 10^9 Archaea

Question 1: Design a basic experiment to test the tolerance of different Archaea species to salt concentrations. Include variables and safety precautions.

Answer: The experiment would involve growing different Archaea species in media with varying salt concentrations. Independent variable: salt concentration; dependent variable: Archaea growth; controlled variables: temperature, pH. Safety precautions include using gloves, eye protection, and working in a biosafety cabinet to prevent contamination and exposure to extreme environments.

Question 1: A study reports that Archaea populations in a saline lake increased after the introduction of a specific pollutant. What could be a possible explanation for this observation?

Answer: Certain Archaea can utilize pollutants like sulfur compounds as energy sources or tolerate high salinity and pollution, giving them a survival advantage in contaminated environments.

Question 1: Discuss the ecological importance of Archaea in extreme environments and their potential applications in biotechnology.

Answer: Archaea play a vital role in biogeochemical cycles, such as nitrogen and sulfur cycling, especially in extreme environments where other organisms cannot survive. Their enzymes and metabolic pathways are valuable in biotechnology for processes like bioremediation, bioenergy production, and industrial applications due to their stability under harsh conditions.

Question 1: How are Archaea being used or could be used in environmental cleanup efforts?

Answer: Archaea can be used in bioremediation to break down pollutants like sulfur compounds or hydrocarbons in contaminated environments, helping to clean up oil spills, mining waste, or polluted water in extreme conditions where other organisms are ineffective.