Classification: Practice Questions

Name the three domains used in the internationally agreed classification system for all life on Earth.

Which of the following describes the correct formatting and meaning of the binomial system of naming a marine species, such as the Great White Shark, Carcharodon carcharias?

Dinoflagellates and diatoms are both microscopic, single-celled protoctists. Which structural characteristic can be used to distinguish a diatom from a dinoflagellate?

The binomial system of naming species uses two parts to define the scientific name of an organism. Which two taxonomic ranks do these two parts represent?

A marine biologist observes a newly discovered organism. It is microscopic and single-celled, but possesses a membrane-bound nucleus and a silica skeleton. To which kingdom and group should this organism be assigned?

According to the binomial system, how is the scientific name of a marine species formed?

State two characteristic features used by scientists to classify a marine organism into the kingdom Animalia rather than the kingdom Plantae.

Distinguish between the kingdoms Plantae and Protoctista using examples of marine organisms and their typical cellular organization.

Organisms in the domain Eukarya are further classified into kingdoms.
(a) List the three main kingdoms of Eukarya found in marine habitats.
(b) For each kingdom listed in (a), provide one distinct marine example.
(c) Explain the purpose of using an internationally agreed system (the binomial system) for naming these species.

A marine research expedition has collected several unidentified specimens from a diverse coastal ecosystem. To accurately catalog these organisms, the scientists must use established classification systems.

(a) The binomial system is used to provide a unique name for every species, such as the killer whale, Orcinus orca. State the two levels of classification used in this naming system and explain why using an internationally agreed system is essential for marine biology.

(b) One specimen is found to have bilateral symmetry, a segmented body, and setae. Identify the phylum this organism belongs to and describe how its body organization differs from an organism in the phylum Mollusca.

(c) The researchers also collected seagrass and kelp. Even though both are photosynthetic marine organisms, they are classified into different kingdoms. State the kingdom for each and describe two structural features of seagrasses that distinguish them from macroalgae like kelp.