A3.1 Diversity of organisms (Organisms): Practice Questions

Which of the following is a characteristic found in the domain Archaea but not in the domain Bacteria?

A cladogram shows the evolutionary relationships between several species. If species A and B share a more recent common ancestor with each other than either does with species C, which of the following inferences about their characteristics is most likely correct?

A newly discovered multicellular eukaryotic organism is observed to obtain nutrients by secreting digestive enzymes externally and absorbing the breakdown products. It possesses cell walls made of chitin. To which kingdom would this organism most likely be classified?

Which of the following statements accurately describes a key difference between organisms classified in Domain Archaea and Domain Bacteria?

A unicellular organism discovered in an extreme hypersaline environment possesses a cell wall that does not contain peptidoglycan and a cell membrane composed of ether-linked lipids. Which taxonomic group does this organism belong to?

State the two components of a scientific name according to the binomial nomenclature system and describe the standard formatting for the genus name when typed.

Examine the provided diagram of four leaf shapes (A, B, C, and D). Construct the first couplet of a dichotomous key that effectively splits these four organisms into two distinct groups based on a single observable trait.

Discuss how extreme environments have driven the evolution of specialized adaptations in organisms belonging to the Archaea domain, providing an example.

Biological classification systems aim to organize the vast diversity of life on Earth.

(a) Explain the hierarchical nature of the Linnaean classification system, listing the main taxonomic ranks in order from most inclusive to least inclusive.
(b) Discuss the limitations of traditional morphological classification when faced with species that exhibit convergent evolution or cryptic species complexes. Explain how modern tools, such as molecular genetics, address these limitations in understanding organismal diversity.