BiologyISC Class 11 · Plant Kingdom

Pteridophytes and Gymnosperms: Vascular Plants without Fruits

Updated 17 October 2026 · Fact-checked

Pteridophytes are seedless vascular plants with a dominant sporophyte and a small, independent gametophyte (prothallus); fertilisation needs water. Gymnosperms are seed plants with naked ovules and seeds, a dominant sporophyte, and heterosporous reproduction; pollen tubes remove the need for water for fertilisation.

Understand Pteridophytes and Gymnosperms

Pteridophytes. Ferns and their relatives; the first terrestrial plants with vascular tissue (xylem and phloem). The main plant is the sporophyte, differentiated into root, stem and leaves (fronds in ferns); sporangia are borne on sporophylls, which may form strobili (cones, as in Selaginella and Equisetum). Spores germinate into a small, multicellular, free-living, mostly photosynthetic gametophyte called the prothallus, which bears antheridia and archegonia. Water is needed for the male gametes to reach the egg. The zygote grows into the new sporophyte.

Classes. Psilopsida (Psilotum), Lycopsida (Selaginella, Lycopodium), Sphenopsida (Equisetum) and Pteropsida (Dryopteris, Pteris, Adiantum).

Homospory and heterospory. Most pteridophytes are homosporous, producing one kind of spore. Selaginella and Salvinia are heterosporous, producing smaller microspores (which become male gametophytes) and larger megaspores (female gametophytes). In these, the female gametophyte is retained on the parent sporophyte and the zygote develops into the young embryo within it, a precursor to the seed habit.

Fern life cycle (Dryopteris). (1) The diploid sporophyte is the dominant, leafy plant. (2) Sporangia are grouped in sori on the underside of the fronds (sporophylls). (3) Spore mother cells divide by meiosis to form haploid spores. (4) A spore germinates into a small, heart-shaped, free-living haploid prothallus. (5) The prothallus bears antheridia (producing flagellated antherozoids) and archegonia (each with one egg). (6) In a film of water the antherozoids swim to the archegonium and fertilise the egg, forming the diploid zygote. (7) The zygote develops into an embryo and then a young sporophyte, which at first depends on the prothallus and then becomes independent.

Gymnosperms. Plants with naked ovules, not enclosed in an ovary, so the seeds are not covered by a fruit (gymnos = naked, sperma = seed). Examples: Cycas, Pinus, Cedrus; Sequoia is among the tallest trees. Roots are tap roots; in Pinus roots have fungal association (mycorrhiza); in Cycas they are coralloid roots, associated with N₂-fixing cyanobacteria. Leaves may be needle-like with thick cuticle and sunken stomata, an adaptation to reduce water loss. They are heterosporous: microsporangia in microsporophylls form microspores (pollen grains) and megasporangia in megasporophylls form megaspores; the sporophylls are arranged in male and female cones. The male gametophyte is highly reduced, and the female gametophyte is retained within the ovule. Pollination is by wind; fertilisation does not require water; the ovule becomes a seed.

Pinus life cycle. (1) The diploid sporophyte is a tree, and it bears separate male and female cones on the same plant. (2) Male cone: microsporophylls carry microsporangia. Microspore mother cells divide by meiosis to form haploid microspores, which develop into winged pollen grains. The pollen grain is the highly reduced male gametophyte. (3) Female cone: megasporophylls (cone scales) bear ovules. One megaspore mother cell in the nucellus divides by meiosis, and one megaspore survives. It forms the female gametophyte with archegonia inside the ovule. (4) Wind carries pollen to the ovule, where it enters through the micropyle (pollination). (5) The pollen grain forms a pollen tube that carries the male gametes to the archegonium. There is a long gap, of many months to about a year or more, between pollination and fertilisation. (6) Fertilisation gives a diploid zygote, which develops into the embryo. (7) The ovule becomes the seed, which is naked and usually winged, and is shed from the cone scales. Water is not needed for fertilisation.

Life cycle summary. Bryophytes: gametophyte dominant. Pteridophytes: sporophyte dominant, gametophyte free-living. Gymnosperms: sporophyte dominant, gametophyte dependent on the sporophyte.

Pteridophytes and Gymnosperms: key facts

Pteridophyte classes: $P s i l o p s i d a : P s i l o t u m ∣ L y co p s i d a : S e l a g in e l l a ∣ S p h e n o p s i d a : E q u i se t u m ∣ P t er o p s i d a : D r y o pt er i s$; Vascular plants without seeds.
Spores: Homosporous: one type | Heterosporous: microspores and megaspores; Selaginella and Salvinia are heterosporous.
Gymnosperm features: Naked ovule
Needle-like leaves in conifers
Cones
Heterospory; Cycas, Pinus, Cedrus.
Dominant phase: Bryophytes: gametophyte | Pteridophytes and gymnosperms: sporophyte; Gametophyte is reduced in gymnosperms.

Pteridophytes and Gymnosperms in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Why a fern needs a damp spot

Suppose a gardener notices that fern spores germinate on damp soil under a shaded wall, but fail on dry sunny ground.

Explain this with reference to the fern life cycle.

Try it first, then show the solutionSolution

The spore germinates into a small prothallus, which bears antheridia and archegonia.
The male gametes are flagellated and need a film of water to swim to the egg.
Without moisture fertilisation fails, so no new sporophyte (the leafy fern) can develop.

Answer: The prothallus needs water for fertilisation.

Memory hook: Pteridophytes are vascular, but the gametophyte stage still depends on water.

Tricks to remember Pteridophytes and Gymnosperms

Short memory aids. Say each one aloud once, then use it on a question the same day.

Naked seed, naked ovule
Gymnosperm = no ovary wall, so no fruit.
Use it when: Defining gymnosperms.
Coralloid = Cycas, mycorrhiza = Pinus
Both are root associations.
Use it when: Roots of gymnosperms.

Pteridophytes and Gymnosperms: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Gametophyte of ferns · 1 mark · MCQBoard level

The gametophyte of a fern is called:
(a) sporophyll
(b) prothallus
(c) protonema
(d) thallus of Marchantia

Try it first, then show the solutionSolution

The small heart-shaped gametophyte of a fern is a prothallus.

Answer: (b) prothallus

Example 2: Pteridophytes · 3 marks · Short answerBoard level

Name the four classes of pteridophytes with an example of each. State two features that make them more advanced than bryophytes.

Try it first, then show the solutionSolution

Psilopsida (Psilotum), Lycopsida (Selaginella), Sphenopsida (Equisetum), Pteropsida (Dryopteris). (1.5 marks)
They have vascular tissue (xylem and phloem) and true roots, stem and leaves. (0.75 mark)
The sporophyte, not the gametophyte, is the dominant phase. (0.75 mark)

Answer: Four classes; vascular tissue and a dominant sporophyte.

Example 3: Heterospory · 4 marks · Short answerHarder board level

Define heterospory with an example. Explain why it is considered a step towards the seed habit.

Try it first, then show the solutionSolution

Heterospory is the production of two kinds of spores, small microspores and large megaspores, as in Selaginella and Salvinia. (1.5 marks)
The megaspore germinates into the female gametophyte inside the megasporangium, retained on the parent sporophyte. (1 mark)
The zygote develops into a young embryo within the female gametophyte on the parent, so the embryo is protected and nourished, like the seed in gymnosperms and angiosperms. (1.5 marks)

Answer: Two spore types; retention of the female gametophyte and embryo on the parent resembles the seed habit.

Example 4: Features of gymnosperms · 4 marks · Short answerHarder board level

Give four characteristics of gymnosperms, with the reasons why the leaves of Pinus are needle-shaped and how Cycas roots differ from those of Pinus.

Try it first, then show the solutionSolution

Naked ovules and seeds; heterosporous; cones; dominant sporophyte. (1 mark)
Needle-like leaves with thick cuticle and sunken stomata reduce water loss in cold, dry conditions. (1.5 marks)
Cycas has coralloid roots associated with N₂-fixing cyanobacteria. (0.75 mark)
Pinus has roots with a mycorrhizal fungus that helps absorb minerals and water. (0.75 mark)

Answer: Naked seed, heterospory, cones, dominant sporophyte; needle leaves reduce water loss; coralloid roots (Cycas) versus mycorrhiza (Pinus).

Example 5: Comparing three groups · 5 marks · Long answerHOTS / competency

Compare bryophytes, pteridophytes and gymnosperms on the following: dominant generation, vascular tissue, seed formation, and the need for water in fertilisation. Why is the gametophyte reduced in gymnosperms?

Try it first, then show the solutionSolution

Bryophytes: gametophyte dominant, no vascular tissue, no seed, water needed. (1.25 marks)
Pteridophytes: sporophyte dominant, vascular tissue present, no seed, water needed for the free-living prothallus. (1.25 marks)
Gymnosperms: sporophyte dominant, vascular tissue present, naked seeds, no water needed since pollen tubes carry the male gametes. (1.5 marks)
The gametophyte is reduced because it is retained within the ovule on the sporophyte, which supplies nutrition and protection. (1 mark)

Answer: The sporophyte dominates in pteridophytes and gymnosperms; only gymnosperms form seeds and avoid water for fertilisation.

Where students lose marks in Pteridophytes and Gymnosperms

The slips examiners see most often, and what to write instead.

Mistake: Calling gymnosperm seeds enclosed
Writing that gymnosperms have fruits.
Do this: They have naked seeds with no ovary or fruit.
Usually costs: 1 to 2 marks.
Mistake: Confusing prothallus and protonema
Using protonema for ferns.
Do this: Prothallus: fern gametophyte; protonema: moss.
Usually costs: 1 mark.
Mistake: Wrong dominant generation
Writing that gymnosperms have a dominant gametophyte.
Do this: The sporophyte is dominant; the gametophyte is highly reduced.
Usually costs: 1 mark.

Exam tips

List the four classes with one example each.
State why heterospory is an evolutionary step.
Tabulate the three groups for comparison questions.
Mention the root associations of Cycas and Pinus.

Practice questions on Pteridophytes and Gymnosperms

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
Which of the following is a heterosporous pteridophyte?
(a) Dryopteris
(b) Selaginella
(c) Equisetum
(d) Pteris
Hint
It produces microspores and megaspores.
Answer
(b) Selaginella
Q2 · 2 marks · Short answerBoard level
What are coralloid roots and where are they found?
Hint
They are associated with cyanobacteria.
Answer
Coralloid roots are small, upward-growing, branched roots of Cycas associated with nitrogen-fixing cyanobacteria.
Q3 · 3 marks · Short answerHarder board level
Why are gymnosperms called "naked-seeded" plants?
Hint
Think about the ovary.
Answer
Their ovules are not enclosed in an ovary; after fertilisation the seeds remain exposed on the cone scales, with no fruit wall around them.
Q4 · 3 marks · Short answerHarder board level
Name the male and female structures of Pinus and the reproductive units in each.
Hint
Cones of two types.
Answer
The male cone bears microsporophylls with microsporangia that produce pollen grains (microspores). The female cone bears megasporophylls with ovules in which the megaspore forms the female gametophyte.
Q5 · 3 marks · Assertion-reasonHarder board level
Assertion (A): Pteridophytes are considered the first vascular land plants. Reason (R): They have xylem and phloem in the sporophyte. Choose: (a) both true and R explains A (b) both true, R does not explain A (c) A true, R false (d) A false, R true.
Hint
Vascular tissue is the key feature.
Answer
(a) Both are true and R explains A.
Q6 · 4 marks · Case-basedHOTS / competency
Case study: Suppose a student compares a fern and a pine tree.
(i) Name the dominant phase in each. (1 mark)
(ii) Name the gametophyte of the fern. (1 mark)
(iii) State which one forms seeds. (1 mark)
(iv) State which one depends on water for fertilisation. (1 mark)
Hint
The fern is a pteridophyte; pine is a gymnosperm.
Answer
(i) Sporophyte in both. (ii) Prothallus. (iii) Pine. (iv) The fern.
Q7 · 4 marks · Short answerHarder board level
Describe the life cycle of a fern such as Dryopteris, from the sporophyte to the new sporophyte.
Hint
Sori, spores, prothallus, antheridia and archegonia, zygote.
Answer
The dominant diploid sporophyte bears sori of sporangia on its fronds. Spore mother cells undergo meiosis to form haploid spores. A spore germinates into a free-living, heart-shaped haploid prothallus bearing antheridia and archegonia. Antherozoids swim through water to the egg in the archegonium and fertilise it. The diploid zygote develops into an embryo and then a new sporophyte.
Q8 · 5 marks · Long answerHOTS / competency
Describe the life cycle of Pinus. Include the male and female cones, pollination, the pollen tube, the gap before fertilisation, and the formation of the seed.
Hint
Both cones are borne on the same sporophyte tree; the gametophytes are reduced.
Answer
The diploid Pinus tree bears male and female cones. In the male cone, microspore mother cells divide by meiosis to form microspores, which develop into winged pollen grains (the reduced male gametophyte). In the female cone, a megaspore mother cell in the ovule divides by meiosis, and one megaspore forms the female gametophyte with archegonia. Wind carries pollen to the micropyle (pollination), and the pollen tube carries the male gametes to the egg. Fertilisation comes many months to about a year or more after pollination and needs no free water. The zygote forms an embryo, and the ovule becomes a naked, winged seed on the cone scale.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Gametophyte of fern?Show answer
Prothallus.
2.Example of a heterosporous pteridophyte?Show answer
Selaginella.
3.What are naked ovules?Show answer
Ovules not enclosed in an ovary.
4.Roots of Cycas?Show answer
Coralloid roots.

Pteridophytes and Gymnosperms: frequently asked questions

Why do pteridophytes need water for fertilisation?

The antherozoids are motile and swim through a film of water to the archegonium.

What is the advantage of pollen in gymnosperms?

Pollen grains carried by wind and a pollen tube carry the male gametes to the egg, so fertilisation does not need free water.

Why are gymnosperms called conifers sometimes?

Many, such as Pinus and Cedrus, bear cones; "conifer" is a name for the cone-bearing gymnosperms.