Question 1: Define Archaea and describe one key difference between Archaea and Bacteria.

Answer: Archaea are a domain of single-celled microorganisms that are distinct from bacteria and eukaryotes; a key difference is that Archaea have unique genetic sequences and membrane lipids that differ from bacteria.

Question 2: List two environmental conditions where Archaea are commonly found.

Answer: Extreme conditions such as high temperatures (thermophiles) and high salinity (halophiles).

Question 1: Explain how the cell membrane structure of Archaea differs from that of bacteria.

Answer: Archaeal cell membranes contain ether linkages instead of ester linkages found in bacteria, and their membrane lipids have branched hydrocarbon chains, which make them more stable in extreme environments.

Question 2: Describe one ecological role of Archaea in the environment.

Answer: Archaea play a crucial role in the nitrogen cycle by converting ammonia into nitrites and nitrates through processes like nitrification.

Question 1: Multiple Choice: Which of the following is a common application of Archaea in biotechnology?

Answer: Bioremediation of oil spills

Question 2: Fill in the blank: Archaea are particularly useful in industrial processes that involve ____________ environments because of their ability to survive extreme conditions.

Answer: high-temperature or high-salinity

Question 3: Long Answer (6 marks): Discuss the importance of studying Archaea in understanding the evolution of life on Earth and their potential uses in future technologies.

Answer: Studying Archaea helps scientists understand the evolutionary pathways of early life forms, as they are considered some of the oldest microorganisms. Their unique adaptations to extreme environments reveal information about Earth's conditions billions of years ago. Additionally, Archaea's enzymes and biochemical processes have potential applications in biotechnology, such as biofuel production, waste treatment, and development of robust industrial enzymes that function under harsh conditions.