Classification Quiz
Questions: 16 · 10 minutes
1. Which sequence lists the major taxonomic ranks from broadest to most specific?
Species, genus, family, order, class, phylum, kingdom, domain
Kingdom, domain, class, phylum, family, order, species, genus
Domain, phylum, kingdom, order, class, family, genus, species
Domain, kingdom, phylum, class, order, family, genus, species
2. A dolphin has a streamlined body and fins like many fish, but it breathes with lungs, produces milk, and shares key anatomical and genetic features with mammals. Which classification approach is strongest?
Classify it as a fish because body shape should outweigh other evidence
Place it in a separate domain because it lives in water
Classify it according to whichever common name is most familiar
Classify it as a mammal using multiple lines of evidence about ancestry
3. A student is using a dichotomous key to identify a plant. What should the student expect at each step?
A list of every species that has the observed trait
A pair of contrasting statements or characteristics
A DNA sequence from the unknown plant
A ranking from the oldest species to the newest
4. New DNA evidence shows that a traditionally grouped set of species does not share the close relationship scientists once assumed. What is the most appropriate response?
Ignore the DNA evidence because classifications cannot change
Reevaluate the group and revise its classification if the evidence supports doing so
Place every species in a separate domain
Use common names instead of scientific evidence
5. Bird wings and insect wings both enable flight but arose from different ancestral structures. How are they best described?
Analogous structures shaped by similar selective pressures
Vestigial structures inherited without a function
Homologous structures showing the same underlying ancestry
Identical traits proving membership in the same class
6. Which written form correctly applies the usual capitalization rule for a two-part scientific name?
Both the genus and species words begin with capital letters
Neither the genus nor species word begins with a capital letter
Homo sapiens
The species word is capitalized, while the genus word is lowercase
7. In the scientific name Felis catus, which word identifies the genus?
catus
Felis catus
Felis
Neither word; the genus is not included
8. Scientists compare the same gene in four species. Species A and B have the fewest sequence differences. What does this evidence most directly suggest?
Species A evolved before all the other species
Species A and B must live in the same environment
Species A and B likely share a more recent common ancestor
Species A and B are necessarily members of the same species
9. If two organisms are classified in the same family, what is the most specific higher rank they must also share?
Order
Genus
Species
Ecological niche
10. The forelimbs of whales, bats, cats, and humans have similar underlying bone arrangements despite serving different functions. What does this similarity most strongly support?
The organisms occupy the same ecological niche
Their forelimbs were inherited from a common ancestor
They should all be classified as members of one species
Their forelimbs evolved independently from unrelated structures
11. What is a primary scientific benefit of classifying Earth’s millions of species?
It assigns every organism a fixed level of importance
It ensures that every species has the same common name worldwide
It prevents classifications from changing when new evidence appears
It organizes organisms and helps communicate similarities and relationships
12. Two animals belong to the same genus but to different species. Compared with two animals that share only a family, what is generally the best inference?
The same-genus animals must look and behave identically
The animals sharing only a family must have the more recent common ancestor
The same-genus animals are generally classified as more closely related
No relationship can be inferred from taxonomic ranks
13. On a cladogram, what does a branch point connecting two lineages represent?
The habitat where both lineages currently live
A common ancestor from which the lineages diverged
The moment both lineages became identical species
A taxonomic rank such as family or order
14. In biological classification, what is a taxon?
A named group of organisms at any taxonomic rank
Only the two-part scientific name of a species
A physical trait found in every living organism
A diagram used exclusively to identify fossils
15. Why can the biological species concept be difficult to apply to organisms that reproduce asexually?
It relies heavily on interbreeding and reproductive isolation
Asexual organisms never pass genetic information to offspring
Asexual organisms cannot be compared using physical traits
It applies only to organisms without cells
16. Researchers find a multicellular organism whose cells contain nuclei and which obtains energy by consuming other organisms. To which domain should it be assigned?
It cannot belong to any domain
Bacteria
Archaea
Eukarya