Which of the following statements is not true? a. Archaea and bacteria have different membrane lipids. b. The cell walls of archaea lack peptidoglycan. c. Only bacteria have histones associated with DNA. d. Only some archaea use CO2 to oxidize H2, releasing methane.

Verified step by step guidance

1. Identify the domain of life each statement refers to, either Archaea or Bacteria.
2. Review the structural components of Archaea and Bacteria, focusing on membrane lipids and cell wall composition.
3. Understand the role of histones in DNA organization and which domains of life typically have histones associated with their DNA.
4. Examine the metabolic processes of Archaea, particularly those involving CO2 and H2 to determine if only some archaea use this pathway.
5. Compare each statement with your knowledge of microbial physiology and genetics to determine which statement is not consistent with established biological facts.

Key Concepts

Differences between Archaea and Bacteria

Archaea and bacteria are two distinct domains of life, differing in their cellular structures and biochemical pathways. One key difference is in their membrane lipids; archaea have ether-linked lipids, while bacteria have ester-linked lipids. This fundamental distinction affects their stability and functionality in extreme environments.

Cell Wall Composition

The composition of cell walls varies significantly between archaea and bacteria. Bacterial cell walls typically contain peptidoglycan, a polymer that provides structural support. In contrast, many archaea lack peptidoglycan and instead may have cell walls made of proteins or polysaccharides, contributing to their resilience in extreme conditions.

Histones and DNA Packaging

Histones are proteins that help package DNA into a compact, organized structure known as chromatin. While bacteria generally do not have histones, archaea possess histone-like proteins that assist in DNA organization. This similarity suggests a closer evolutionary relationship between archaea and eukaryotes compared to bacteria.