Quiz: The Four Classes of Pteridophytes
Pteridophytes are the first true terrestrial plants with vascular tissues, yet their reproduction still depends on water. That paradox is exactly what makes their classification so revealing.
In this quiz you will work through the four recognised classes — Psilopsida, Lycopsida, Sphenopsida and Pteropsida — and the genera that anchor each one: Psilotum, Selaginella, Lycopodium, Equisetum, Dryopteris, Pteris and Adiantum.
What to expect
- Matching each class with its representative genera.
- Distinguishing the homosporous condition from the heterosporous condition.
- Recognising the reproductive events that foreshadow the seed habit.
- Structural clues such as jointed stems, strobili and leafless branching axes.
Twenty questions, moderate difficulty. Read each stem carefully — the distractors are built from real pteridophyte features, so precision matters.
Q1. Into how many classes are the pteridophytes further classified?
The pteridophytes are further classified into four classes: Psilopsida, Lycopsida, Sphenopsida and Pteropsida.
Q2. Which genus is the representative of the class Psilopsida?
Psilopsida is represented by Psilotum, a genus whose sporophytes lack true roots and leaves.
Q3. Which pair of genera represents the class Lycopsida?
Lycopsida contains Selaginella and Lycopodium, plants with small, simple leaves and often distinct strobili.
Q4. Equisetum is placed in which class of pteridophytes?
Sphenopsida is represented by Equisetum, distinguished by its jointed architecture of nodes and internodes.
Q5. Which set of genera belongs to the class Pteropsida?
Pteropsida gathers the ferns proper — Dryopteris, Pteris and Adiantum.
Q6. The sporophyte of Psilotum is characterised by which feature?
Psilotum lacks true roots and leaves, bearing instead dichotomously branching aerial axes that arise from a rhizome.
Q7. A compact, cone-like structure bearing spore-producing organs, conspicuous in many lycopsids, is called a:
The strobilus is a compact cone-like structure bearing spore-producing organs and is a conspicuous feature of Lycopsida.
Q8. Which structural feature most clearly distinguishes Equisetum from the other pteridophyte genera studied?
Equisetum shows jointed architecture: stems are clearly divided into nodes and internodes, with branches arising at the nodes.
Q9. Plants in which all the spores are of similar kinds are described as:
In the majority of pteridophytes all the spores are of similar kinds; such plants are called homosporous.
Q10. Which two genera are cited as heterosporous because they produce macrospores and microspores?
Genera like Selaginella and Salvinia produce two kinds of spores, macro (large) and micro (small) spores, and are known as heterosporous.
Q11. Within Lycopsida, which genus is homosporous and therefore contrasts with Selaginella?
Lycopodium is homosporous, so it sits beside the heterosporous Selaginella as a contrasting example within the same class.
Q12. The megaspores and microspores of heterosporous pteridophytes germinate to give rise to which structures, respectively?
The megaspores germinate to give rise to female gametophytes, while the microspores give rise to male gametophytes.
Q13. In heterosporous pteridophytes, the female gametophytes are:
The female gametophytes in these plants are retained on the parent sporophytes for variable periods.
Q14. Where does the development of the zygote into a young embryo take place in heterosporous pteridophytes?
The development of the zygotes into young embryos takes place within the female gametophytes.
Q15. The retention of the female gametophyte and embryo development upon the parent sporophyte is regarded as a precursor to:
This event is a precursor to the seed habit, considered an important step in evolution.
Q16. Which class is matched with the genus Adiantum?
Pteropsida includes Dryopteris, Pteris and Adiantum.
Q17. Which of the following correctly pairs a class with its representative genus?
Lycopsida is represented by Selaginella and Lycopodium. The other pairings are incorrect: Psilopsida is Psilotum, Sphenopsida is Equisetum, and Pteropsida is Dryopteris, Pteris and Adiantum.
Q18. The gametophytes of pteridophytes are described as free-living, mostly photosynthetic thalloid structures called:
The gametophytes are free-living, mostly photosynthetic thalloid structures called prothallus, requiring cool, damp, shady places to grow.
Q19. Why is the spread of living pteridophytes limited to narrow geographical regions?
Because of the specific restricted requirement of the gametophytes and the need for water for fertilisation, the spread of living pteridophytes is limited and restricted to narrow geographical regions.
Q20. Which statement about the pteridophyte life cycle is correct?
The zygote produces a multicellular well-differentiated sporophyte, which is the dominant phase of the pteridophytes. Water is required for transfer of antherozoids released from the antheridia to the mouth of the archegonium.