Classification and identification keys

1. Which statement best describes how organisms are first placed into classification groups?

1. They are grouped using features that they share.
2. They are grouped only by the habitat in which they were found.
3. They are grouped only by their adult body mass.
4. They are grouped alphabetically by common name.

2. Which description matches the biological definition of a species used in this course?

1. Organisms that have exactly the same appearance
2. Organisms that live in the same habitat
3. Organisms that can reproduce with one another to produce fertile offspring
4. Organisms that eat the same type of food

3. Which name uses the correct two-word order and capitalisation?

1. Homo
2. Homo sapiens
3. Homo Sapiens sapiens
4. sapiens Homo

4. What makes an identification key dichotomous?

1. It always identifies exactly two species.
2. It uses only measurements with two digits.
3. It can be used only twice for each specimen.
4. Each step presents two alternative statements.

5. What relationship do modern classification systems aim to reflect?

1. Evolutionary relationships between organisms
2. The order in which organisms were discovered
3. The economic value of each organism
4. The distance between their present habitats

6. Equal lengths of a corresponding DNA region are compared. Species P and Q differ at 2 base positions, while P and R differ at 18. What is the best conclusion from this evidence?

1. P and R must be the same species.
2. Q evolved directly from P.
3. P and Q probably share a more recent ancestor than P and R.
4. R has no evolutionary relationship with P.

7. An organism has a mycelium made of hyphae, no chloroplasts and obtains soluble nutrients after external digestion. To which kingdom does it belong?

1. Plant
2. Fungus
3. Animal
4. Prokaryote

8. A unicellular organism has circular DNA free in its cytoplasm and has no nucleus. Which kingdom contains it?

1. Animal
2. Plant
3. Protoctist
4. Prokaryote

9. A microscopic single-celled organism has a nucleus and chloroplasts. Which kingdom is the best placement?

1. Protoctist
2. Prokaryote
3. Fungus
4. Animal

10. Which feature provides the clearest evidence that an unfamiliar vertebrate is a mammal?

1. It has four limbs.
2. It breathes air.
3. It has hair and females produce milk.
4. It lives on land.

11. An animal has feathers, a beak and lays hard-shelled eggs. Which vertebrate group is it in?

1. Reptiles
2. Birds
3. Mammals
4. Amphibians

12. A vertebrate has dry scaly skin and lays eggs with leathery shells on land. How should it be classified?

1. Fish
2. Bird
3. Amphibian
4. Reptile

13. Which set of features is most characteristic of an amphibian?

1. Moist skin and jelly-coated eggs laid in water
2. Feathers and a hard-shelled egg
3. Hair and milk production
4. Dry scales and a leathery-shelled egg

14. An adult vertebrate lives in water and has fins, scales and gills. Which group does it belong to?

1. Amphibians
2. Reptiles
3. Fish
4. Mammals

15. An arthropod has three body regions, three pairs of legs and one pair of antennae. Which group is it in?

1. Arachnids
2. Insects
3. Crustaceans
4. Myriapods

16. An arthropod has two main body regions, four pairs of legs and no antennae. Which group is it in?

1. Insects
2. Crustaceans
3. Myriapods
4. Arachnids

17. Which combination identifies a crustacean rather than the other named arthropod groups?

1. Two pairs of antennae and more than four pairs of legs
2. No antennae and four pairs of legs
3. One pair of antennae and three pairs of legs
4. One pair of antennae and many similar leg-bearing segments

18. A land arthropod has many similar body segments, many legs and one pair of antennae. How is it classified?

1. Insect
2. Arachnid
3. Myriapod
4. Crustacean

19. A plant has roots, a stem and fronds but produces no flowers or seeds. It releases spores. Which group is it in?

1. Monocotyledon
2. Fern
3. Dicotyledon
4. Fungus

20. A flowering plant has one cotyledon, parallel leaf veins and flower parts in multiples of three. How is it classified?

1. Fern
2. Dicotyledon
3. Protoctist
4. Monocotyledon

21. Which feature combination supports identifying a flowering plant as a dicotyledon?

1. Two cotyledons and branching net-like leaf veins
2. One cotyledon and parallel leaf veins
3. Fronds and spore production without seeds
4. No nucleus and circular DNA free in cytoplasm

22. Which description states the required structural features of a virus?

1. A nucleus surrounded by cytoplasm and a cell membrane
2. A cell wall containing a nucleus and chloroplasts
3. Genetic material surrounded by a protein coat
4. Circular DNA free in cytoplasm inside a cell wall

23. Use this key: 1a wings present — go to 2; 1b wings absent — species R. 2a one pair of wings — species S; 2b two pairs of wings — species T. A specimen has wings, with two pairs. What is its identification and route?

1. Species R by route 1b
2. Species T by route 1a → 2b
3. Species S by route 1a → 2a
4. Species T by route 1b → 2b

24. An unfamiliar organism is multicellular, has cellulose cell walls and chloroplasts, and makes organic nutrients by photosynthesis. What is the best classification from these features?

1. Fungus, because it has cell walls
2. Animal, because it is multicellular
3. Protoctist, because it contains chloroplasts
4. Plant, because the combined features match the plant kingdom