Final Answer:
True, lipids in archaeal cytoplasmic membranes lack true fatty acids.
Step-by-step explanation:
Archaeal cytoplasmic membranes do not primarily contain fatty acids as seen in bacterial and eukaryotic cell membranes. Instead, archaeal lipids consist of isoprenoid chains connected to glycerol via ether linkages, forming unique membrane structures called isoprenoid ethers or diether and tetraether lipids.
These lipids contribute to the extreme resilience of archaea in harsh environments due to their resistance to high temperatures, pH extremes, and salinity. Unlike fatty acids found in bacterial and eukaryotic membranes, these isoprenoid chains provide stability through their highly branched and often tetrafunctional nature. The absence of fatty acids in archaeal membranes is a defining characteristic that distinguishes them from other domains of life.